QfortiBll 5llniiiBr0ita Hthrarg Sttjaca, JJew ^ntk BOUGHT WITH THE INCOME OF THE SAGE ENDOWMENT FUND THE GIFT OF HENRY W. SAGE 1891 Cornell University Library D 521.J66 Topography and strategy in '[je war 3 1924 027 831 589 Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924027831589 TOPOGRAPHY AND STRATEGY IN THE WAR BY DOUGLAS WILSON JOHNSON Associate Professor of Physiography in Columbia University WITH MAPS AND ILLUSTRATIONS NEW YORK HENRY HOLT AND COMPANY 1917 b.KP Copyright, 1917 BY HENRY HOLT AND COMPANY PabliBhed November, 1917 PKEFACE As a student of land forms who is more or less familiar with the broader topographic features of Europe the writer has had a professional as well as a personal interest in the great war. He was particularly anxious, to discover how far modern military operations are still affected by the element of terrain; and whether guns which hurl high ex- plosive shells with marvelous accuracy over lofty mountain ridges and across the widest river valleys, aeroplane service which permits better observations than can be secured from the most favorably situated topographic eminences, and modern engineering devices which refuse to be daunted by the deepest stream or steepest cliff, have eliminated the surface features of the land as an important factor in mili- tary calculations. Aided by large scale maps showing with precision the topography of the principal battle fronts he has, from the first days of the war, followed with some care the changes on each front, and has found ample indication that the role played by land forms in plans of campaign and movements of armies is no less important today than in the past. To emphasize this interesting relationship be- tween inanimate Nature and the science of war is one of the objects of this book. Another object, and perhaps the more important, is to place before the reader such a picture" of each theater of war as shall enable him to follow with greater ease and livelier interest the movements of our own and our Allies' troops. If the surface features of Europe control in im- portant measure the issues of the various campaigns, con- tributing to success in one field and imposing failure in understanding of the war despatches printed daily in the press. Maps ordinarily accessible to the public are in- accurate and vague, and there exists no single volume giving such maps, diagrams, photographs, and word descriptions of the theaters of war as will provide the reader with good mental pictures of those fields on which the battles of democ- racy are being waged. To meet this need, so far as I am able, is the chief purpose of this volume. In order to give it a maximum of usefulness I have endeavored to combine scientific accuracy in the descriptions of topography with a treatment which avoids the use of technical terms. Each important theater of war is discussed in a special chapter, which deals with the more striking surface features affecting military operations. Then follow one or more chapters reviewing the history of the campaigns in that particular area during the first three years of war, and pointing out the manner in which the element of terrain has affected army movements. It will be seen that this method of treatment incidentally provides a summary history of the chief military operations on the several fronts up to the time when America took her place among the combatants, and it is hoped this feature of the volume will prove of service to the reader. ISTo effort has been made to prepare a complete history of the war, however, and the writer makes no claim for special accuracy of detail or novelty of material in so far as this phase of the work is concerned. His task has been to picture the theaters of war and to emphasize the influence of land forms upon military opera- tions; and in recording the succession of military events he has relied upon the approximate dates and position marks indicated on his own war maps, supplemented by such mili- tary reviews and reports of operations as are available to PREFACE V any reader. He is quite sensible of the fact that when the full history of the war is written many errors of detail in these pages may iiave to be corrected; for while the maps themselves are accurate, official reports of troop positions issued during the war are always very generalized, usually extremely meager, and often purposely misleading. It is believed, however, that no corrections which may be required will in any wise alter the validity of the general conclusions set forth in the pages which follow. To the American Geographical Society I must express my obligation for their generous permission to make full use of a number of essays on the war which I contributed to their publications, the Bulletin of the Society and its suc- cessor, The Geographical Review. The essays which ap- peared in the Bulletin and which were in part reprinted in the Journal of the Military Service Institution, have been entirely rewritten; others appearing more recently in the Review have been brought up to date but otherwise not greatly modified; while a number of the chapters appear here for the first time. All of the maps were specially prepared under my direction by the draughtsmen of the American Geographical Society. The diagrammatic view of the eastern theater of war was drawn for me by one of my former students, Dr. A. K. Lobeck. It is appropriate also that I should acknowledge my debt to the published articles and books of Hilaire Belloc, whose reviews of military operations during the war have been of service in clarifying details of troop movements. Douglas Wilson Johnson. Columbia University, September 1, 1917. CONTENTS CHAPTER Preface I The Western Theater of War II The Plan of Campaign . III The Invasion of France IV The Deadlock .... V The Eastern Theater of War VI East Prussian Campaigns . VII Early Galician Campaigns . VIII Campaigns in Western Poland IX Teutonic Plan of Campaign in 1915 X The Great Russian Retreat XI The Italian Theater of War XII Campaigns for Italia Irredenta XIII The Balkan Theater of War XIV Campaigns Against Serbia . XV The Rumanian Theater of War XVI Conquest of Rumania . Index PAGE iii 1 20 26 41 50 62 69 82 88 97 121 128 144 162 177 186 205 ILLUSTRATIONS Alpini equipped with skis fighting on a glacier in the mountains of the Trentino Frontispiece FACINO FAGR The broad, flat floor of the middle Rhine valley, as seen from the foothills of the Black Forest Mountains 10 Schlucht Pass on crest of Vosges Mountains, showing contrast be- tween steep eastern face (foreground) and more gentle western slope (background). In lower left-hand corner is the carriage road ascending to the pass 12 Giintherstal, showing typical topography of the lower courses of valleys heading against the steep scarps of the Vosges and Black Forest Mountains 12 Meandering gorge of the Moselle River, showing great bend near Marienburg and the even skyline of the upland through which the river cuts its trench . 14 Gorge of the Rhine River through the Slate Mountains of west- ern Germany, showing level skyline of the flat-topped uplands. At the right are ruins of one of the ancient castles which once guarded this highly important trade route, while below is the modern village of St. Goar 16 Typical road on the gently undulating plain of northern France. This is the type of surface which made possible the rapid Ger- man advance on Paris 18 Sea cliffs cut in the margin of the plain of northern France, show- ing horizontal rock layers underlying the plain's surface . . 18 Old forts at Namur guarding trench of the Meuse River through the Ardennes Mountains 26 Gorge of the Meuse River at Dinant, showing steep rocky sides of the gorge, the flat character of the upland, and the old fortress of Dinant 26 A typical scene on the flat plain of Flanders 30 The level plain of Belgium, across which the main German advance on Paris was launched. Note the intensive cultivation of the plain and the network of roads. In the distance is the town of Audegem, burning as a result of artillery fire .... 30 First line of east-facing escarpment east of Paris, covered with vineyards. The view is taken near Epernay 36 The marsh of St. Gond at the foot of the first escarpment. The few routes through the marsh were rendered impassable by destroying the bridges 36 viii ILLUSTEATIONS ix FACIKS PAGE The flat-floored valley of theMame River in the vicinity of Meaux 38 Flooded floor of the Petit Morin valley, a tributary of the Marne which played an important rOle in the struggle . . 38 Official French photograph of a part of the Somme battlefield, taken from an aeroplane, showing ruined village of Soyecourt and the system of trenches then occupied by the Germans. Note the numerous shell craters and the smoke of bursting shells 40 Typical view of the Polish plain near Lodz. The motor car was destroyed by a bomb from an aeroplane 56 German soldiers advancing toward Warsaw across the level sur- face of the plain of Poland 56 The Niemen River spanned by a German pontoon bridge ... 64 Russian troops intrenched on the east bank of the Niemen, firing on German forces attempting to cross the river .... 64 Fortification at Rozan. In the distance is the flat, marshy floor of the Narew valley 72 The San River spanned by a temporary bridge constructed by Russian army engineers 72 When mountaineering and warfare are one. Austrian troops scaling a precipitous slope 78 Broad expanse of the Polish plain as seen in wet weather. The troops are part of a German cyclist division 82 The broad barrier of the Vistula River crossed near Wyszogrod by a pontoon bridge. Note the sandbar islands in the stream which made the problem of bridge construction less difficult ... 90 Fortifications bordering the Vistula River to render more diffi- cult its passage by an enemy 90 Great bridge at Warsaw destroyed by the Russians before their retreat in order to prevent the ready passage of the Vistula by the pursuing Germans 104 German troops crossing the Visula barrier to Warsaw on a pon- toon bridge ■ • • • ■^"* Imposing barrier of the Trentine Alps as seen from an Italian outpost on Monte Pasubio ^^^ Typical terrain of the Italian front in the Dolomite Alps of the ^^^ Trentino A trench in the rocks and snows of the Alps. Note the snow-laden barbed wire entanglements in front of the trench .... l^s Military transport service in the high Alps of the Trentino. Two Italian scouts traveling on the teleferic railway . . . id^ Bridges over the Isonzo River at Gorizia under fire A bursting shell is seen at the left, while in the stone bridge one arch has been destroyed. The Podgora foothills of the Julian Alps form the background X ILLUSTRATIONS PACING PAGE Line of trenches on the Carso front 140 Italian sharpshooters on a peak overlooking the deep gorge of the Isonzo River in the mountains north of Gorizia . . . 142 Italian artillerymen dragging a giant howitzer up a steep moun- tain trail in the Alps 148 One phase of mountain warfare. An engine driving rock drills used in excavating a tunnel under Mount Tofana. By means of this tunnel the Italians undermined and blew up an Austrian fortress on the mountain top . . . •. . . . .148 Serbian troops crossing the Kolubara River barrier on the ruins of a bridge which was repeatedly destroyed and repaired during the fighting along this stream 158 A barren basin or " polye " in the Serbian mountains. The bad road has caused the cart to upset with resulting injury to the driver 158 A portion of the Austrian army halted on the north side of the Save River barrier. Temporary military bridges are seen in the distance 166 A Serbian convoy retreating through a narrow section of the Morava Valley north of Nish 166 General Sarrail surveying the Vardar trench near Krivolak, north of the Demir Kapu gorge 172 French camp in the broad valley of the Vardar River south of the Demir Kapu gorge 172 Cavern used as a secret Austrian gun position 182 Watergap of a tributary to the Olt River entering the lowland between the main range of the Transylvanian Alps and the minor parallel ridges to the south 188 Part of the great Cernavoda Bridge over the Danube and its marshy floodplain Igg Red Tower Pass in the Transylvanian Alps 194 Predeal Pass, the main avenue of communication across the Tran- sylvanian Alps from Bukharest to Kronstadt . . . .194 DIAGRAMS AND MAPS TAGS Fig. 1 — Diagrammatic view of the western theater of war, show- ing the principal plateaus and plains, mountains and lowlands, cliff scarps and river trenches which have influenced military operations .... facing 4 Fig. 2 — ^Main defensive position of the Allied armies at the bat- tle of Mons-Charleroi-Namur 28 Fig. 3 — Approximate German positions at the battle of the Marne 34 Fig. 4 — ^Trench of the Aisne River .39 Fig. 5 — Terrain of the Verdun district 45 Fig. 6 — Diagrammatic view of the eastern theater of war, show- ing the Carpathian Mountains and their chief passes, the plain of Poland, the hill and lake country of East Prussia, the river trenches and marshes, and other features of the terrain which have influenced military operations in the east facing 50 Fig. 7 — Natural defenses of the Warsaw-Petrograd railway . . 65 Fig. 8 — Positions of the Russian front before and after the great retreat of 1915 91 Fig. 9 — Map of the Galician terrain, showing successive defensive positions of the Russian armies in earlier stages of the great retreat 98 Fig. 10 — River and marsh barriers protecting the Warsaw salient 106 Fig. 11 — Natural defenses of the Grodno salient . .110 Fig. 12 — ^Approximate position of the Russian front when the Vilna salient was most strongly developed . .113 Fig. 13 — ^Natural barriers in the Riga-Dvinsk region . . . 115 Fig. 14 — ^The Italian theater of war, showing thei principal mountain and plateau barriers, river trenches and marshes, affecting the Italian campaigns facing 121 Fig. 15 — The Isonzo front, showing the Carso and Bainsizza plateaus and the mountain peaks which formed the principal Austrian strongholds 137 Fig 16 — ^Map showing barriers and trenches of the Balkan Peninsula • • • ''""'"^ ^^^ Fig. 17 — ^Natural defenses of the armed camp of Saloniki . 175 Fig 18 — ^Map showing the chief natural defensive barriers of Rumania . /""iny "^ TOPOGRAPHY AND STRATEGY IN THE WAR CHAPTEE I THE WESTERN THEATER OF WAR The violation of Belgian neutrality was predetermined by events which took place in western Europe several million years ago. Long ages before man appeared on the world stage Nature was fashioning the scenery which was not merely to serve as a setting for the European drama, but was, in fact, to guide the current of the play into blackest tragedy. Had the land of Belgium been raised a few hun- dred feet higher above the sea, or had the rock layers of northeastern France not been given their uniform down- ward slope toward the west, Germany would not have been tempted to commit one of the most revolting crimes of history and Belgium would not have been crucified by her barbarous enemy. For it was, in the last analysis, the geological features of influence western Europe which determined the general plan of cam- terrain paign against France and the detailed movements of the invading armies. Military operations are controlled by a variety of factors, some of them economic, some strategic, others political in character. But many of these in turn have their ultimate basis in the physical features of the region involved, while the direct control of topography upon troop movements is profoundly important. Geological his- tory had favored Belgium and northern France with valuable 2 TOPOGRAPHY AND STRATEGY IN THE WAR deposits of coal and iron -jvliich the ambitious Teuton coveted. At the same time it had so fashioned the topography of these two areas as to insure the invasion of France through Bel- gium by a power which placed " military necessity " above every consideration of morality and humanity. The surface configuration of western Europe is the key to events in this theater of war ; and he who would understand the epoch- making happenings of the last few years cannot ignore the geography of the region in which those events transpired. The Natural Defenses of Paris The Paris What is now the country of northern France was in time Basin j^j^g p^gj. ^ pg^j. ^f ^jjg gpg_ When the sea bottom deposits were upraised to form land, the horizontal layers were un- equally elevated. Around the margins the uplift was great-^ est, thus giving to the region the form of a gigantic saucer or basin. Because Paris today occupies the center of this basin-like structure, it is known to geologists and geog- raphers as " the Paris Basin." Since the basin was formed it has suffered extensive erosion from rain and rivers. In the central area where the rocks are flat, winding river trenches, like those of the ■f. Aisne, Marne, and Seine, are cut from three to five hundred feet below the flat upland surface. To the east and north- east the gently upturned margin of the basin exposes alter- Plateaus ^sXe layers of hard and soft rocks. As one would naturally and low- expect. Soft layers like shales'* have readily been eroded to form broad flat-floored lowlands, like the Woevre^ district east of Verdun. The harder limestone and chalk beds are not worn so low, and form parallel belts of plateaus, the " cotes " of the French. These plateau belts and the inter- vening parallel lowlands are best shown in bird's-eye view by a diagrammatic sketch of western Europe (Fig. 1). THE WESTEEN THEATER OF WAR 3 The diagram represents a block of the earth's crust, cut out so as to show in cross section the manner in which the hard rock layers have been eroded to form the plateau cliffs. The fact that the rock layers dip toward the center of East- the basin has one striking result of profound military im- gcarpf portance. Every plateau belt is bordered on one side by a steep, irregular escarpment, representing the eroded edge of a hard rock layer ; while the other side is a gentle slope having about the same inclination as the dip of the beds. As will be seen from the diagram, the steep face is uniformly toward \ Germany, the gentle back-slope toward Paris; and the crest of the steep scarp always overlooks one of the broad, flat lowlands to the eastward. The military consequences arising from this peculiar topography will readily appear. It is not difficult to understand why the plateau belts have long been called " the natural defenses of Paris." -^ Imagine yourself at Paris, and start on a tour of inspec- tion eastward to the German border. Pirst you traverse the central plateau of the Paris Basin, called by many the Isle of France because of an ancient theory that the cir- cular line of bordering cliffs was cut by the waves of the sea. Here and there, especially if you turn northward or southward in your journey, you come suddenly upon the edge of a river valley trenching the plateau across which Valley you are traveling. Descending the steep slopes of the valley ''^"'^ ®® wall, which are often clothed in forests, you reach the flat valley floor several hundred feet below, and make your way ' over the winding stream. Perhaps the season is wet, and you wade through marshes on both sides of the river until the dry land of the opposite valley wall is reached. Toiling painfully up the slope you at length come out again upon the flat upland of the plateau surface. Pausing to rest, you look back at the obstacle you have just traversed, and reflect TOPOGRAPHY AND STRATEGY IN THE WAR Quarries and caverns The first escarp- ment that a number of such obstacles cross the plateau in parallel courses from east to west. You realize that they must prove serious barriers to the advance of armies moving southward or northward; and as you remember that two of these ob- stacles bear the names of the Marne and the Aisne, you have a fuller understanding of two notable chapters in recent military history. As you journey onward you pass numerous quarries, some of them broad and deep. Cavern mouths tempt you to ex- plore vast subterranean excavations where limestone or chalk in large quantities has been removed, leaving vast galleries and chambers which could easily house many thousands of troops safe below reach of the heaviest shell explosions. An army intrenched behind the natural moat of one of the east- west river trenches, as for example the Aisne, and utilizing surface quarries and underground caverns for the protection of its men, might well consider itself impregnable against every assault of the enemy. Musing thus, you continue eastward, until suddenly you arrive at the brink of the first line of east-facing escarpment. Behind you stretches the plateau whose surface features you have just been studying. In front of you, to the east, spread out below like a gigantic map, is the level surface of the Champagne lowland. As you look down upon it you see roads, like narrow white ribbons, bordered on both sides by green vineyards, while the steep slopes of the escarpment itself are often cleared of their trees and cultivated. At your feet, where the west-flowing Marne cuts its gateway through the escarpment, lies the town of Epernay, while to the north the towers of Rheims Cathedral mark the similar gateway of a branch of the Aisne. Southward the marsh of St. Gond occupies a former river valley on the flat floor of the plain, its boggy surface a trap which captured many pieces of German artillery. Far out over chalky flats to the ^^TT'TiT^^^ i "y^y^ "! '^^y, 1 '^^^^ Figure 1. Diagrammatic view of the western theater of war, showing the p: which have influenced military operations. The under 1.1 plateaus and plains, mountains and loWlands, cliff scarps and river trenches I rock structure is shown in the front edge of the block. i-u-cj v¥ XLio 1 XLiniN J. xiikaTER op war 5 east lies the famous armed camp at Chalons. Nothing is hidden from view in that broad panorama of plain. What a position is yours from which to check a westward View from advance upon Paris ! Every enemy movement would be *'^® '^^^^^ open to observation from the crest of the scarp, and could be broken up by fire from artillery concealed in ravines back from the plateau face. Assaults on intrenched positions on the slopes and crest of the scarp would be made with every advantage on the side of the defending troops. The level plain below offers little opportunity for the offensive to secure concealed artillery positions from which to make preparation for the uphill infantry charges. It was re- ported in early despatches of the war that during the Battle of the Marne the German center, stretching eastward from Sezanne at the base of the cliffs farther south, was sub- jected to a disastrous artillery fire from the crest of the scarp which broke up concentrations of reserves on the plain and prevented the reinforcement of the German line at critical moments. Profoundly impressed with the strength of this natural The plain defense line before Paris, you descend to the plain of Cham- pagne^*"' pagne and move eastward over its surface. For thirty-five or forty miles your course is over a dry chalky soil, a region ^ comparatively unfruitful where only scattered growths of trees relieve the semi-desert aspect. This is known as the " Dry Champagne," as the rain which falls on the porous chalk soon sinks to depths which the plants cannot reach. Farther east is the " Wet Champagne," where a narrower belt of impervious clay keeps more of the water on the surface, there to form numerous brooks and marshes, and to support a goodly forest growth. Crossing the Wet Champagne, you begin a gradual east- The ward ascent which does not end until you stand, for a second IT°^„ time, at the crest of an east-facing scarp. The lowland ment TOPOGRAPHY AND STRATEGY IN THE WAR The third escarp- ment Forgt d'Argonne Verdun escarp- ment Plain of the Woevre now spread out below you to the east is traversed by the winding course of the upper Aisne, slightly entrenched in the floor of the plain; and the main river gateways cutting through the escarpment are marked by the towns of Rethel and Vitry. Again you are impressed with the topographic advantages favoring the defenders of Paris from an attack from the east. The conditions are essentially those already noted from the crest of the first escarpment, save for the absence of the arid, chalky soil of the Dry Champagne. You push across the valley of the upper Aisne, on up the gentle back slope of the next plateau belt, until for a third time you stand at the crest of a steep east-facing escarpment, and look down upon a lowland spread out like a map at your feet. All about you the plateau is heavily forested, and cut here and there by the deep, wild gorges of numerous streams, which flow westward to the lowland just left be- hind, or eastward to the lowland at the base of the scarp. This wooded plateau belt is the Foret d'Argonne, where more than one battle of France has been fought. Descending the face of the Argonne scarp and crossing the valley of the Aire River, you continue eastward across a minor plateau strip and reach the winding trench of the Meuse. Past immortal Verdun and its outlying forts, you press on to the crest of the next great scarp. What a view here meets the eye ! To the north and south stretches the long belt of plateau, cut into parallel ridges by east- and west-flowing streams, — ridges like the Cote du Poivre, whose history is written in the blood of brave men. Below, to the east, lies the flat plain of the Woevre, whose im- pervious clay soil holds the water on the surface to form marshes and bogs without number. Here the hosts of Prus- sian militarism fairly tested the strength of the natural defenses of Paris, and suffered disastrous defeat. Moving westward under the hurricane of steel hurled upon them THE WESTERN THEATER OP WAR 7 from above, their mancBuvering in the marshes of the plain easily visible to the observant enemy on the crest, the in- vading armies assaulted the escarpment again and again in fruitless endeavors to capture the plateau. Only at the south where the plateau belt is narrower and the scarp broken down by erosion did the Germans secure a precarious foot- hold, thereby forming the St. Mihiel salient; while at the north entering by the oblique gateway cut by the Meuse Kiver, they pushed south on either side of the valley only to meet an equally disastrous check at the hands of the French intrenched on the east-and-west cross ridges. Viewing the battlefields from your vantage point on the plateau crest, you read a new meaning in the Battle of Verdun. You comprehend the full significance of the well-known fact that it was not the artificial fortifications which saved the city. It was the defenses erected by !N'ature against an enemy from the east, skilfully utilized by the heroic armies of France in making good" their battle cry, " They shall not pass." The fortified cities of Verdun and Toul merely defend the two main gateways through this most important escarpment, the river gateway at Verdun being carved by the oblique course of the Meuse, while the famous " Gap of Toul " was Toul Gap cut by a former tributary of the upper Meuse, long ago deflected to join the Moselle. Other fortifications along the crest of the scarp add their measure of strength to the natural barrier. Once more you resume your eastward progress, traverse The Metz the marshy and blood-soaked plain of the Woevre, ascend ment the gentle back slope of still another plateau belt, and stand at last on the crest of the easternmost escarpment. Topo- graphically this is the outermost line of the natural defenses of Paris, and as such might be claimed on geological grounds as the property of France. But since the war of 1870 the northern part of this barrier has been in the hands of 8 TOPOGRAPHY AND STRATEGY IN THE WAR Xancy gateway The Grand Couronng River gateways Germany, who purposed in 1914 to widen the breach already made in her neighbor's lines of defense. Metz guards a river gateway cut obliquely through the scarp, and has, therefore, a strategic value of the very highest importance. Farther south is Nancy, marking the entrance to a double gateway through the same scarp. Here in the first week of September, 1914, under the eyes of the Kaiser, the German armies, moving southward from Metz, where they were al- ready in possession of the natural barrier, attempted to capture the Nancy gateways and the plateau crest to the north and south. Once again the natural strength of the position was better than the Kaiser's best. From the Grand Couronne, as the wooded crest of the escarpment is called, the missiles of death rained down upon the exposed posi- tions of the assaulting legions. The Nancy gateway was saved, and more than three years from that date is still secure in the hands of the French. The test of bitter ex- perience has fully demonstrated to the invading Germans that it was no idle fancy which named the east-facing scarps of norther France " the natural defenses of Paris." It is but reasonable to expect that many of the rivers of northern France should flow down the dip of the rock layers and converge toward the center of the Paris Basin, where the beautiful city itself is located. A glance at a map, or at the diagram opposite page 4, will show that this expecta- tion is fully realized. Most of the river gateways through the concentric lines of escarpments have been carved by these converging streams, or by streams which did so converge before they were deflected to other courses by drainage re- arrangements resulting from the excavation of the parallel belts of broad lowlands. Of course these natural openings through the plateau barriers have great strategic value, and must figure prominently in any military operations in the Paris Basin. They constitute the only feasible routes along THE WESTERN THEATER OF WAR 9 wHich armies and their impedimenta may cross the barriers, as elsewhere steep grades and poor roads are the rule. At each of them a town of greater or less importance has sprung Strategic up, and both town and gateway are protected either by per- gateways ma'nent forts or hastily constructed field fortifications. So great is the strategic value of the principal gateways, such as those near Toul and Verdun, that we find them marked by some of the most strongly fortified cities in the world. The fortifications dominate the roads, canals, and railway lines which pass through the openings, and must be reduced before the cities can be occupied and the transportation lines freely used. This explains the significance of the frequent mention, especially in the war despatches of the first year, of such towns as La Fere, Laon, Rheims, Epernay, and Sezanne guarding gateways in the first line of cliffs east of Paris; of Rethel and Vitry in the second line; of Bar-le- Duc in the third; of Verdun and Toul in the fourth; of Metz and ISTancy in the fifth ; to say nothing of other points in the same and lesser scarps not considered in this volume. The importance of the strategic gateways will readily Relation . « . , 1 . 1 . ■ • 1 •! "1" gate- appear if we consider their relation to principal railway ways to routes. ISTo railway of eastern France can traverse the ""ailroads country from the German frontier to Paris without seeking out and passing through several of these fortified gateways in succession. Take, for example, the main through line ■< from Strassburg to Paris. After crossing the German bor- der it follows the valley of the Meurthe a short distance to reach one of the two ISTancy gateways. Turning west through this opening in the Metz-Nancy escarpment, it makes straight for the famous Gap of Toul in the Verdun-Toul escarp- ment. Once through the Gap, the line bends north to find an opening in the Foret d'Argonne scarp near the town of Bar-le-Duc. Westward from here the route runs some thirty or forty miles to Vitry, where there is a gateway through lowland 10 TOPOGRAPHY AND STRATEGY IN THE WAR the Eethel-Vitry escarpment. At Vitry the line divides, one branch turning northwest to cut through the innermost line of cliffs at the Epernay gateway, the other continuing west to make use of the gateway at Sezanne. Evidently there are along this one line at least five strategically im- portant defiles through a corresponding number of military obstacles, all of which defiles must be controlled by the armies which would make free use of the Strassburg-Paris route. The Sedan Toward the northwest the several lines of plateau escarp- ments gradually descend, and ultimately merge with the undulating plain of northern France. The low land be- tween these fading escarpments on the one hand and the rough country of the Ardennes Mountains on the other, gives a roundabout but easy pathway along which one might reach Paris by swinging west beyond the ends of the scarps. Longwy, Montmedy, Sedan, and Mezieres are the important points along this route, which is followed by a railway of much strategic value and which was quickly seized by the Germans after they had reduced the antiquated fortifications affording it a poor protection. As a route for an advance on Paris it is too circuitous to be of prime importance. The Vosges Mountains and Rhine Valley Beyond the limits of the natural fortifications of Paris are three outlying regions, each possessing a peculiar topog- raphy which has indelibly stamped its impress on the western campaigns. These regions are: to the east, the Vosges Mountains and the Valley of the Rhine ; to the north- east, the mountains of western Germany and southern Bel- gium ; to the north, the plain of northern France and Bel- gium. Let us examine these regions in the order named. It will be seen from the diagram, opposite page 4, that the THE WESTERN THEATER OP WAR 11 folded rocks underlying the horizontal layers of the Paris Basin come to the surface at the east, forming rugged mountains from which the later beds have been completely eroded. Originally this eastern rim of the Basin was a The Rhine broad north-south arch, with a gently rounded summit; but a north-south block of rock extending along the crest, and bounded by two parallel fractures or rifts in the earth's crust, dropped down several thousand feet, giving the broad, flat-floored valley of the middle Rhine, or the Ehine Gra- ben as it is known to the Germans. The river has spread ■ thick mantle of sand and silt over the surface of the down- Iropped block, and now swings in a gracefully curving channel in its own deposits. The fertile plains of this valley floor constitute that part of the province of Alsace which the French are most anxious to recover from the Germans. The two remaining limbs of the former arch, facing in- TheVosges ward toward the down-dropped central strip, are known as the Vosges Mountains on the west and the Black Forest on the east. Each of these ranges has a gentle slope away from the valley, and a steep face toward the valley representing the once nearly vertical fracture surface now eroded into sharp crested ridges and narrow ravines. Both slopes of each range are sufficiently rugged to make agriculture diffi- cult and the building of roads and railroads expensive ; hence the ranges are but little developed, and much forested land remains. But it is on the steeper slopes which lead abruptly downward to the flat floor of the Ehine Valley that the ridges are most rugged and the forest most unbroken. Here the movement of large bodies of troops is particularly diffi- cult, especially if they must ascend the slopes in the face of a determined enemy. It was not political expediency alone which led the French The to invade southern Alsace at the beginning of the war. The o7ATs°ace international boundary line follows the crest of the southern 12 TOPOGRAPHY AND STRATEGY IN THE WAR Contrasted slopes of the Vosges Vosges, and it was much easier for the French to move up the gentle west slope of the Vosges, capture the passes, and then sweep down the steep eastern face upon the flat plains about Miilhausen, than it was for them to cross the boundary farther northwest, where no such advantage was furnished by the topography. A French soldier, writing home from the battle line in the Vosges, described the in- fluence of topography upon the fighting in that district in the following words : " Our task has been much easier in the southern Vosges than farther north. In the south it is all downhill after we cross the border; but in the north we must fight uphill against the Germans after we have entered their territory, as there the boundary line lies west of the mountain crest." It has been stated in press reports that a commander of German forces at Miilhausen, ordered to lead his men across the Vosges Mountains into France, made three futile at- tempts to carry the heights of the range in the face of French artillery. Then came an urgent message from the Kaiser : " The crest of the Vosges must be carried at any cost." A fourth desperate assault by the intrepid com- mander ended in his defeat. Ketiring to his quarters the unhappy general, according to the story, committed suicide, first sending to his Kaiser this message : " The Vosges can- not be crossed. Come and try it yourself." I would not care to vouch for the truth of the story ; but it serves to illustrate the peculiar surface features of the Vosges which render their ascent comparatively easy from the French side of the border but very difficult from the German side. This is the key to the significant fact that after three years of desperate offensives the only place where the German troops have been unable to expel the French from German soil is on the steep eastern face of the Vosges Mountains. In this connection it is interesting to note that should Schlucht Pass on crest of Vosges Mountains, showing contrast between steep eastern face (foreground) and more gentle western slope (back- ground ) . In lower left-hand corner is the carriage road ascending to the pass. Guntherstal, showing typical topography of the lower courses of valleys heading against the steep scarps of the Vosges and Black Forest Mountains. THE WESTERN THEATER OP WAR 13 tlie French succeed in pushing the Germans back to the east side of the Rhine, their further eastward advance in southern Germany would then be opposed by precisely the Terrain of same topographic difficulties which have long retarded the j-Qj-e^i^'^'' westward movement of the Germans in southern Alsace. The Black Forest will replace the Vosges in immediate impor- tance, and while the Germans hold the crest and more gentle eastward slope of this range the French will find assaults against the steep west-facing scarp both costly and difficult. Not far south of Mlilhausen, but beyond the limits of the The drawing, on page 4, the Vosges Mountains descend to a low gateway pass which connects the Rhine valley with the valley of the Saone in eastern France. In this pass, guarding the strategic gateway from one valley to the other, stands the mighty fortress of Belfort, the southernmost of the great fortifications erected against a German invasion. Entrance to France by this route is easy, so far as the natural physical features alone are concerned; and in the commercial inter- course between the two nations the gateway has played an important role. But the opening is narrow enough to be effectively defended by the fortress in its center and to per- mit the concentration of troops in such numbers as to render its passage by an invader extremely difficult. Whether the fortress which withstood the attacks of the Germans in 1870 can defy the guns which reduced Liege, Namur, Maubeuge, and Antwerp will be determined only in case the Germans can push the French field army back far enough to bring their heavy siege artillery within range of the walls of Belfort. The Mountains of Western Germany and Southern Belgium ISTorth and west of the Vosges Mountains the older series The moun- of folded rocks, exposed at the surface around the margin upland of the Paris Basin, have not been raised so high as in the 14 TOPOGRAPHY AND STRATEGY IN THE WAR Vosges. Instead they form an upland of moderate eleva- tion, -which was once a nearly level erosion plane ; but which, since the uplift, has been cut into hills and valleys by many branching streams. This hilly country is known as the Slate Mountains, the Haardt, the Eifel, and by other names in Germany, and as the Ardennes in southern Belgium. Although usually described as mountainous, the most strik- ing feature of the area is the remarkably even sky-line which appears in every distant landscape view, and which is proof that the much folded rocks were once worn down to a surface of faint relief, after which warping raised the surface to its present position and permitted its dissection by river erosion. The upland is now so badly cut up by streams that cross-country travel is difficult, and transporta- tion lines tend to follow the valleys. Valley Two main rivers cut deep trenches across this upland from defiles southwest to northeast — the Moselle and the Meuse; while the lower Rhine transects it from southeast to northwest. Despite its excessively meandering course the Moselle gorge has been, from time immemorial, one of the chief pathways ; through the broad mountain barrier, and the strongly forti- fied city at its junction with the Rhine bears a name, Coblenz, which reminds us of the fact that in Roman times this Avas recognized as an important " confluence." In the Gorge present war the Moselle has served as the chief line of com- of the munication for one of the German armies of invasion, but Moselle -j- i * i- ... . . if the Allies succeed in driving the invaders out of Belgium and back toward the Rhine, the great natural moat of the Moselle trench would change its role, and become a military barrier of the first importance behind which the Germans might hope to check the Allied advance. Gorge The gorge of the Meuse is the second great natural high- of the T^^j through the upland barrier, and cleaves its way through the heart of the Ardennes Mountains. Less winding than TiiJiJ WJ^iSTKKJN THEATER OP WAR 15 the Moselle, it is scarcely less important, especially if we include the branch gorge of the Sambre, -which joins the )( main trench at Namur. For the Sambre leads one south- westward to a low divide whence the headwaters of the Oise may be entered and followed directly to Paris. The com- bined Meuse-Sambre-Oise valley route is followed by a \ through railway line from Berlin to Paris, and for this reason was heavily guarded by the fortifications of Liege, Huy, ISTamur, and Maubeuge. Commanding the main gorge of the Meuse southward from iN^amur were the forts at Dinant and Grivet. Both the Meuse and the Sambre trenches, now serving as Defensive principal lines of communication and supply for the Ger- the^Meuse- man armies, were utilized by the Allied armies in August, Sambre 1914, as protective barriers behind which they waited to receive the first great shock of the German onslaught. The -^ main Allied front faced north, and between Namur and Charleroi was protected by the lesser gorge of the Sambre; while the right flank enjoyed the admirable protection of the deep, steep-sided canyon of the Meuse. Those familiar with the steep rocky walls of this larger trench will readily appreciate what a high defensive value it must have pos- sessed. The causes of its ultimate abandonment by the Allied forces are touched upon in another chapter. The famous gorge of the Rhine, with its precipitous walls Gorge of from which ruined castles look down upon the swift current of the great river, is better known to the world than the valleys of the Moselle and Meuse. Prom the earliest times it has been one of the chief routes of transportation and communication in western Europe, and today iive impor- tant transport lines thread the narrow defile, — two railways, one on either side of the river ; two auto roads, one on either side; and the steamboat route on the river itself. In few places in the world can one find such a striking contrast as Defensive and offen- sive value of the Riiine gorge 16 TOPOGRAPHY AND STRATEGY IN THE WAR when, standing on the upper rim of the gorge, he looks out over the quiet farms and sleepy villages on the upland surface, then down upon the busy thoroughfare where trains, autos, wagons, and steamboats form a constant stream of hurrying traffic. The two ends of the Rhine trench are guarded by Mainz and Cologne, two of the strongest fortified cities in Ger- many ; while near the middle stands the strong fortress of Coblenz. Here then is a natural moat of impressive dimen- sions, carrying a swift, deep river, and heavily fortified at its most accessible points. German armies retreating from Belgium in the north could hope to check, along this trench, the most vigorous assaults of a pursuing enemy. Thus far, however, we are concerned with the Rhine trench as a line of communication connecting central Geniiany with military bases in the west from which attacks on France could most conveniently be launched. It is evident that two armies with headquarters at Coblenz and Cologne, and supplied by the railways, auto roads, and steamer routes which pass through the Rhine gorge, could attack France simultaneously if one ascended the Moselle to Luxemburg and the other passed from Cologne westward around the north side of the hilly country to the Meuse, and then fol- lowed southward up that valley. Hence it was that in the early weeks of the war we heard much of the " army of the Moselle " and the " army of the Meuse " ; and the capture of Liege, Huy, Namur, Dinant, and Givet marked the progress of the latter army along the best pathway through the Ardennes. The Plain of Northern France and Belgium, Terrain of Northward from Paris, and west of the fading belts of the undu- . i ■ i j lating plateaus and scarps which characterize the eastern and P ^^" northeastern sectors of the Paris Basin, stretches the un- THE WESTERN THEATER OP WAR 17. dulating plain of Normandy, Picardie, and Artois. The underlying rock layers are practically horizontal and are exposed in picturesque manner along the coast where the waves of the sea have cliffed the margins of the land. Branching streams of moderate size have dissected the sur- face of the plain into a complex system of low hills with gently rounded slopes, those sufficiently large to be called rivers having eroded shallow valleys whose flat floors are not infrequently, as in the case of the Somme, covered with ponds and marshes. Above the valley bottoms the uplands are dry, and crossed by a network of excellent roads and railways. Even where valleys interrupt the surface the slopes are gentle, and in all this region there is not a single military barrier of the first magnitude. Marshy valleys of small streams, hill slopes, and occasional low ridges would figure in intensive fighting where opposing armies were dead- locked ; but striking topographic barriers do not exist. In Belgium the plain continues, but takes on a double aspect. From the margin of the hilly Ardennes north- westward toward the sea the surface is much like that de- scribed above, except that it is in general more gently un- dulating, even monotonously level over broad areas. Beads and railways make a dense network affording excellent com- munications in every direction. Nearer the coast, however, Flat the land slopes down beneath the level of high tide, and be- j'ia™der3 comes an absolutely flat, treeless plain. Belts of sand dunes along the shore and artificial dikes alone prevent the waters of the sea from flooding the land when the tide is high. Elvers crossing this belt must themselves be diked to prevent the indefinite spreading of their waters. Thus it happens that they are practically converted into canals, and like the lower Yser are called indifferently " canals " or " rivers." A close-set network of smaller canals helps to drain the flat, marshy surface, but forms an endless system of obstacles to 18 TOPOGRAPHY AND STRATEGY IN THE WAR Fertility of the plain Strategic value of the plain The Lifege gateway free movement through the region. The level of permanent groundwater is at or near the surface, and trenches dug in the marshy soil can scarcely be effectively drained. Trench-life here is at its worst, and omnipresent mud adds its miseries to field life on the Flanders plain. The higher parts of the plain, both in France and in Bel- gium, are covered with deposits of fine-grained loess and loam which afford a fertile soil easily cultivated. As a result the population is dense, and agriculture flourishes. Forests have been largely removed to permit the intensive farming of every available acre. It will be evident, there- fore, that both the richness of the country and its favorable topography combine to make this plain a natural pathway from eastern and central Europe into France. It has, indeed, been called the gateway to northern France, and forms part of the greater plain belt over which one may travel by rail from northeastern Russia to the Pyrenees without passing through a single tunnel and without rising 600 feet above the level of the sea. From the military standpoint it presents four prime advantages: it is inter- rupted by no topographic barrier of serious importance; it is supplied with numerous parallel roads and railways by means of which to advance simultaneously different columns of troops; it is productive enough to supply food for the sustenance of large armies for long periods of time; and it passes close to important coal and iron deposits in the borders of the Ardennes, and has, indeed, important coal fields lying immediately below its level surface. In concluding our examination of the plain, let us note one peculiar feature of its position in eastern Belgium. Here the rugged country of the Ardennes reaches north to the vicinity of Liege, while Holland sends far southward a great peninsula of her territory in the form of the province of Limburg. The Belgium portion of the plain is thus nar- Typical road on the gently undulating plain of northern France. This is the type of surface which made possible the rapid German advance on Paris. iSea cliffs cut in the margin of the plain of northern France, showing horizontal rock layers underlying the plains surface. THE WESTERN THEATER OF WAR 19 rowed to a neck of land only a few miles in width. German troops desiring to enter the Belgian plain would thus find themselves confined between the bill country on the south and Dutch territory on the north. Across the narrow gate- way cuts the valley of the Meuse Eiver, and blocking pas- sage of both river and gateway stood the forts of Liege. Manifestly free access to the broader plain beyond would not be possible until the forts had been reduced and their guns silenced. We have completed our survey of the surface features of Summary the western theater of war, and have found that the Vosges Mountains, the mountains of western Germany and the Ardennes in Belgium constitute a broad outer zone of com- paratively difficult country, within which concentric belts of plateaus with east-facing scarps defend the most direct approaches to Paris. Only through Belgium into northern France . is there a level pathway, free from obstacles, of great breadth most of the way, and provided with every facility for the rapid movement and prolonged sustenance of large armies. In the following chapters we will see how profoundly these physical features affected the general plan of the German campaign and the detailed movements of the opposing armies. CHAPTEE II THE PLAIST OF CAMPAIGN First If the reader will turn back to the diagram opposite page 4 invasion ^^ ^^^^ ^^^ ^^ ^ glance that four principal routes of inva- sion were open to Germany in her campaign against France. She could, for example, concentrate her main armies in the valley of the Rhine with bases at Strassburg and Miil- hausen, and in the country about Metz to enter by the so- called Lorraine gateway. An advance westward from Strass- burg or Mlilhausen would encounter the high and steep east- facing scarp of the Vosges Mountains, a topographic feature which as we have already seen imposes practically im- possible conditions upon a German offensive. On the other hand the main advance from this region might be made by turning either end of the mountain barrier, passing through the Belfort gateway between the Jura Mountains and the southern end of the Vosges ; or between the north end of the range and Luxemburg, through the gateway of Lorraine. In the first instance the ring fortifications of Belfort block the way, and since they effectively command every transporta- tion line through the pass their complete reduction would be necessary before an advance would be possible. From the southern foothills of the Vosges to the neutral territory of Switzerland in the Jura foothills the distance is but ten or fifteen miles, and the narrowness of the gap would favor the defense and prevent satisfactory manoeuvering of the at- tacking forces. Firmly intrenched in the gateway, their left flank secure against the difficult Vosges and their right flank protected by the neutral Swiss hills, supported by one 20 THE PLAN OF CAMPAIGN 21 of tHe four strongest fortified camps of France and supplied by adequate rail connections with the rear, the French armies could render an advance into their country by this route at best a slow and costly undertaking. In order to understand the German plan of campaign we Necessity must remember that rapidity of action was of its very essence, favoring ^ German strategists have long maintained, and German states- ^ »"''** men at the outbreak of the war frankly asserted that to win the war the German armies must drive swiftly to the heart of France and bring that country to her knees before Russia should have time to mobilize and become a pressing danger on the east. In the German plan no route of invasion was practicable which would impose on the advance any appre- ciable delay. German and Austrian heavy artillery might account for the permanent fortifications of Belfort within reasonable time once they were fairly under fire; but the topography favored a long and obstinate defense from field works, which would perhaps prevent the big guns from com- ing within effective range of their objectives. The Belfort gateway might become the scene of important subsidiary operations, but German necessities required a topographi- cally more favorable route for the main invasion. The Lorraine gateway is broad and since the war of The 1870, largely in German territory. Metz is an admirable gateway fortified base and is connected with Strassburg by excellent rail communications. It was by this route that the Prus- sian armies passed in the former war, whereas at the gate of Belfort they knocked in vain. West of Metz the German border is closer to Paris than at any other point. Here, then, would seem to be an appropriate point from which to launch the main attack upon the French capital. But to reach this conclusion is to forget the surface con- figuration of the Paris Basin. Just over the French border is the broad, marshy plain of the Woevre. Dominating it 22 TOPOGRAPHY AND STRATEGY IN THE WAR Natural defenses facing the Lorraine gateway The first route im- practicable on the west is the steep escarpment crowned at short in- tervals by permanent fortifications from Verdun to Toul, and offering exceptionally advantageous positions for tem- porary field works commanding the plain below. At the two points mentioned the only practicable gateways through the barrier are heavily fortified. Beyond to the west the same unfavorable topography is repeated again and again; always a steep scarp toward G-ermany, commanding a plain over which the invading troops must advance; always a gentle back slope down which the defending armies might retreat to the next scarp if too heavily pressed, while rear- guards on the formerly occupied crest held the invaders temporarily at bay. If victorious along one plateau scarp, the invading armies would be checked at the next and com- pelled to fight the battle anew. Delays at the fortified gate- ways must be expected even if the forts were invested and the main armies pressed on to the barrier next west. Narrow and few in number, the gateways afford insufficient lines of communication for vast armies advancing and fighting, while the construction of new roads suitable for heavy traffic up the escarpments and over the plateaus would be an engineer- ing feat involving an enormous expense in labor and time. Clearly the route from the middle Rhine country west- ward into France must be eliminated as the main path of invasion in a campaign demanding rapidity of action as its chief object. The failure of the Crown Prince's army to break through the gateway at Verdun, the failure to cap- ture the plateau crest west of the Woevre, and the failure to secure the Nancy gateways and reach the Gap of Toul are sufficient vindication from the military standpoint of the German Staff's determination to avoid the difficult terrain of northeastern France and the delays it would inevitably impose on military operations. The belt of fortifications alone would probably have weighed but little in the Teuton THE PLAN OF CAMPAIGN 23 plans. Their confidence in their heavy artillery was supreme, and was fully justified by the speedy fall of every fort coming effectively under its fire. But the defenses of Nature cannot be blasted away by the devices of man, and it was these defenses and not the permanent forts which saved Nancy, Toul, and Verdun. A second route of invasion is from the northeast, follow- Second ing the course of the Moselle trench to Luxemburg and thence invasion into France by way of Longwy or Metz. Such an advance could base on Coblenz and Trier, and would in the one instance involve the violation of neutral Luxemburg, and in the other bring the armies to the same advanced base (Metz) used by the troops moving west from the middle Khine. In either case the further progress of the armies would encounter the same difficult terrain of the Paris Basin, which rendered impracticable the first route, as described above. Large armies must undoubtedly push through the Lorraine gateway, capture the important irOn deposits within easy reach of Metz, and forestall any attempt of the French to invade Germany by this route. Biit the main striking arm of the German military machine must operate along some other path. To a lesser degree the route from Cologne, around the Third north side of the Ardennes, past Aix-la-Chapelle, and so to yo^te of the trench of the Meuse through the mountains, is open to the same objections. Once the invaders were in French territory the plateau scarps could be crossed near their west- ern extremities where they constitute less formidable ob- stacles. Nevertheless the terrain is far from favoring a speedy advance on Paris. The scarps are sufiiciently pro- nounced to give commanding artillery positions and to re- strict free movement to a limited number of gateways. The innermost line of cliffs is especially forbidding, and its gate- ways are guarded by the fortifications of La Fere, Laon, invasion 24 TOPOGRAPHY AND STRATEGY IN THE WAR Fourth route of invasion Objections to the fourth route Rheims, and Soissons. Moreover, to conduct the main offensive with its principal line of communications a single railway running back through a narrow mountain gorge in hostile territory would be inadvisable if more favorable con- ditions could be found a short distance to the west. The " army of the Meuse " was, therefore, destined to play a subsidiary role in the invasion. There remains the fourth route, by way of the Belgian plain. Entering, as before, by the Liege gateway, invading armies could spread westward around the northern side of the Ardennes, through Louvain and Brussels, swinging grad- ually southwest past Mons and Charleroi, Cambrai and Le Cateau, on past St. Quentin, and so down to Paris. The left flank could profit by the Sambre-Oise valley route, while the right flank could swing as far out over the plain as cir- cumstances required. The pathway here is broad and level and no topographic obstacle bars the way. It is a route which enables an invader to take in the flank the entire series of plateau barriers farther east. Koads and railways are excellent and numerous, permitting the rapid simul- taneous advance of different columns of troops. The coun- try is fertile and highly productive, providing sustenance for large armies. With the occupation of this route would go the conquest of deposits of coal and iron of immense importance to the invaders. Back of the armies operating in Erance would be a broad network of first-class lines of communication and supply. Assuredly of the four possible routes of invasion this is the one incomparably the best so far as its physical characteristics are concerned. There existed, however, some serious objections to an advance on Paris by way of the Belgian plain. The dis- tance from the nearest point on the Franco-German bound- ary, near Metz, to Paris is about 170 miles as the aeroplane flies. From the German-Belgian border to Paris, via the THE PLAN OP CAMPAIGN 25 Belgian plain, the distance is approximately 250 miles. The latter route is, therefore, nearly fifty per cent, longer than the legitimate route directly from German territory into France. Not only this. The longer route involved the vio- lation of Belgian neutrality, and if Belgium and England were faithful to their treaty obligations and true to their national honor, must inevitably bring the Belgian army and the British army and navy into the field against the invader. Yet this was precisely the route over which the great mass of the German armies were hurled. The smooth Belgian plain was to serve as the slot along which the Ger- man bolt should reach the heart of France. Surely the choice of an invasion through Belgium must Military have been dictated by some very compelling reason to justify demanded it in the minds of the German General Staff. That reason tlie fourth is to be found in the topographic features of western Europe which rendered a swift advance on Paris impossible from the east, but comparatively simple from the north over the broad pathway of the Belgian plain. " He who is menaced as we are can only consider the one and best way to strike," said the German Chancellor. " Belgian neutrality had to be violated by Germany on strategic grounds," cabled the Kaiser to President Wilson. Military Necessity, the one true god of the Prussian autocracy, demanded the speedy death of France ; and to gain the one secure route to the heart of the victim, German honor and Belgian peace were sacrificed on the altar of Prussian militarism. CHAPTER III THE INVASION OE EEANCE The Advance Attack on the Li&ge gate The gate opened On the afternoon of the 4th of August, 1914, there ap- peared at the mouth of the Liege gateway small bodies of German troops. The first important operation of the great ■war was to shatter the defenses of this narrow pass and gain admittance to the Belgian plain. The gateway is only a dozen miles in breadth, and the forts of Liege effectively command the railway lines which converge to pass through it before spreading out again on the plain beyond. Evi- dently the gathering hosts of the Kaiser could not fling themselves over the plain upon France until the advance guard had opened the gate. A few days later the city was entered, but most of the forts held out. A cavalry screen pushed through the gateway and advanced westward over the plain; but lacking proper support it was forced on the 13th to make a partial retreat before the brave little Belgian army. The battle for the possession of the pass was not yet decided, and in the mean- time troops and supplies were congested at the entrance await- ing free passage before the real invasion could seriously com- mence. The delay was becoming dangerous, for the ad- vantages to be reaped from a sudden sweep over the plain might be lost through failure to gain prompt admission to its level surface. Einally on August 14th or 15th, eleven days after the struggle for the gateway began, the western- most fort, Lonein, with General Leman, the heroic de- 26 Old forts at Namur guarding trench of the Meuse Eiver through the Ardennes Mountains. Copyright by Underwood & Underwood. Gorge of the Meuse Eiver at Dinant, showing steep rocky sides of the gorge, the flat character of the upland, and the old fortress of Dinant. THE INYASION OP PRANCE 27 fender of Liege, fell into German hands and the sweep toward Paris began. Meanwhile, the French and British were taking advan- Allies tage of the delay imposed by geographic conditions at the terrain entrance to the plain, in order to prepare for the shock which ^attk'^* would quickly follow the debouching of the main German armies through the gateway. Instead of setting themselves athwart the course of the main German advance over the plain, they selected a topographically more favorable posi- tion in the northern foothills of the Ardennes. This posi- tion possessed at least three notable geographic advantages: it occupied and, therefore, completely blocked the Meuse and Sambre passageways through the Ardennes ; it was defended in front by the gorge of the Sambre from JSTamur to Char- leroi, and on the right flank, the flank next the advancing Germans, by the deeper gorge and larger stream of the Meuse; and it flanked the course of the German advance, compelling the invaders to turn and fight on a line selected by the defense, since they could not continue over the plain with their flank constantly exposed to an Allied attack from the hills. Let us look more closely at this first strategic position of Terrain of the Allied armies. The main front faced north, and from ^f Mons- Mons to Charleroi was constituted by the British Expedi- Charleroi- . Namur tionary Force, while the French 5th Army continued the line from ' Charleroi to Namur. Unfortunately the British had in front of them no protective topographic barrier of importance; but for all or most of its length the French 5th Army lay behind the gorge of the Sambre. In this Sambre portion of its course the Sambre is a strongly meandering ^^^^ river, which follows a winding trench cut 300 feet or more below the upland surface. The flat floor of the trench is 500 or 600 yards in breadth, and covered with open meadows. As a rule the southern wall of the trench is steep and for- 28 TOPOGRAPHY AND STRATEGY IN THE WAR Gorge of the Meuse ested. An enemy advancing from the north would find it difficult to cross the exposed meadows, bridge the river, and dislodge the defenders from the wooded heights beyond. With the Allied front facing north along the line of the Sambre, there was, of course, danger of a flank attack by German troops advancing from the east. Fortunately as a protection against this danger the main gorge of the Meuse ©MONS '^ ea Esa ESI ea ca csa p-NAMU^ gd555~^- 31 J ^'1': f^'' ^''^ ^^GIVET Figure 2. Main defensive position of the Allied armies at the battle of Mons-Charleroi-Namur. was admirably located, and behind this natural moat lay the French 4th Army extending from JSTamur southward past Dinant to the fortress of Givet. This stretch includes the most formidable part of the Meuse trench. Less strongly winding than the Sambre, it is cut deeper below the Ardennes upland and has steeper walls. The river is deeper and broader, and practically fills the bottom of the trench. Precipitous cliffs of bare rock rise in places several hundred feet from the water's edge. Where the slope is less steep the walls are heavily forested. Without question this is the most formidable obstacle in the Ardennes district. THE INVASION OF FRANCE 29 It will be seen that the combined Allied fronts formed a salient with both sides protected by topographic barriers of imposing magnitude, but with the apex thrust far out The toward the advancing Germans. This apex being the June- Namur^ tion of two principal natural pathways through the moun- salient tains, it was the locus not only of an important town, but also of the most valuable crossings over the two rivers. The strategic value of Namur was thus very great, and for its protection there had been constructed a ring of modern forts. Located at the junction of the north-facing and east- facing Allied armies, and guarding passages across the rivers, which, if captured by the enemy, would enable him to breach both topographic barriers and flank both armies out of their positions, it is clear that fortified l^^famur was the key to the Allied defense. The fortress was, moreover, the solid sup- port upon which the right of the main Allied front rested in supposed security. On the 20th of August the German artillery opened fire on the forts of Namur. At the same time the German in- fantry had wheeled south from the plain to attack the main Allied front behind the Sambre, while the French 4th Army behind the Mouse was also feeling the enemy pres- sure. It now developed that the Allies had made some fatal miscalculations. In the first place they had woefully under- estimated the enormous strength of the German invasion by^^ way of the plain. Overwhelming masses of the best Prussian troops were hurled against the Sambre barrier, while the heaviest attacks of all were concentrated on the more remote but topographically unprotected western end of the line. At the eastern end the forts of ISTamur melted away with in- credible rapidity under the German fire. Less than twenty- four hours after they opened fire, German troops entered the city, and the next day controlled the vital passages over the Meuse and Sambre. On August 22d the defensive line of 30 TOPOGRAPHY AND STRATEGY IN THE WAR the Meuse-Sambre trench was abandoned, and there began the retreat which was not to end till the stage was set for the Battle of the Marne. Enveloping The phenomenal sweep of the German armies across the Uirough" Belgian plain into northern France now proceeded apace, the Bel- Yon Kluck's great army swung far to the west and south, through Tournai, Arras, and Amiens, overlapping the west- ern end of the Allied line and constantly threatening to envelop it. The infantry advancing by parallel columns on different roads, and supplied by an efficient motor trans- port service, moved swiftly over the smooth surface. Cease- lessly pressed by the extreme rapidity of the German ad- vance, the British army withdrew southwestward into France, along the margin of the plain just west of the Oise valley, turning to face more and more toward the northwest ~^in order to defeat Von Kluck's efforts at envelopment. In time this brought the British contingent into a position par- Oise valley allel to the Oise valley, and the heart-breaking retreat was barrier gj.g^ checked when the exhausted Expeditionary Force put this important barrier between itself and the pursuing Ger- mans on a line from Noyon to La Fere. Not before this had the plain offered an obstacle sufficiently serious to check the pursuit and afford the pursued a real breathing space. Here was a fairly large river meanderi'ng excessively through a series of marshes on the flat floor of a broad valley, with the wooded hills of Noyon protecting the left end of the line and the fortress of La Fere at the right. Although not a defensive barrier of the first importance, it offered temporary security. Meanwhile the French were falling back toward a concave line running from Paris to Verdun, in prepara- tion for the offensive which was to bear the name of the Battle of the Marne. Thus far the assault through the plain of Belgium had succeeded beyond measure. Germany had moved an in- Central Nerca. A typical scene on the flat plain of Flanders. American Press. The level plain of Belgium, across which the main German advance on Paris was launched. Note the intensive cultivation of the plain and the network of roads. In the distance is the town of Audegem, burning as a result of artillery fire. THE INVASION OP PRANCE 31 credible number of men at an incredibly swift pace across the low, level pathway into Prance. The Allied armies were in peril from the swift swing around the western end of their line, and it was believed Paris would soon fall before the heavy guns moving rapidly southward over the plain. Pate seemed about ready to set the final seal of approval upon Germany's choice of the topographically most favorable route into the enemy's country. The Battle of the Marne In its simplest terms the Battle of the Marne consisted. The plan on the part of the Germans, in an attempt to swing round the ° ^ ^ vestern end of the Allied line and envelop it from that direction, at the same time breaking through the Allied cen- ter far to the east and forcing the remainder of the western half of the line back on Paris,, thereby completing the process of envelopment and creating a second Sedan on a grand scale. ^ On the part of the Prench the intention was similar: a flanking movement around the west end of the German line, and a break through their center, which should split the in- vading forces, thus insuring the complete envelopment or precipitate retreat of the western half. It is notable that of these four movements the two flank attacks were begun on the plain north of Paris, while the two attempts to break the enemy's center were staged on the low plain of Champagne. Only subsidiary movements consequent upon the main efforts were assigned to the troops operating over the more difficult topography of the intervening plateau with its deep cut river trenches. Let us follow, in outline, the chief events in this most im- Minor portant battle of the war, noting as we go the role played by [he" Marne the surface features of the country over which two vast army River groups were contending for a victory which should, in all 32 TOPOGRAPHY AND STRATEGY IN THE WAR Joffre's strategic retreat to favorable terrain likelihood, determine the course of world history for many centuries to come. Although called the Battle of the Marne, the trench of this important river cannot properly be said to have played a determining role in the issue of the struggle. Only once, in fact, were the opposing armies aligned on op- posite sides of this natural barrier for any great part of its length, and then only for a brief space of time. It was the battle of the plateau of the Marne and of the Marne Eiver and its tributaries, including especially the Ourcq, Petit Morin, and Grand Morin; and the iinal issue was in fact determined on the low plain of Champagne farther east. Maps of the battle line at critical stages in the engagement usually fail to show that striking parallelism between army positions and topographic features which most readily gives one an appreciation of the influence of land forms on military operations. But it would be a serious mistake to draw from this the conclusion that such influence was any the less real. The Battle of Liege gave the Allied armies time to assem- ble in the triangle guarded by the Sambre and Meuse gorges. The Battle of Mons-Charleroi-Namur, in its turn, was not expected by the Allies to accomplish the impossible task of crushing the German armies, but was designed to afford time for troops to assemble farther south, where the final struggle might take place under conditions more likely to bring decisive victory to the Allied arms. Joffre's strategic retreat not only lengthened out the enemy's lines of com- munication through many miles of hostile territory, but compelled the German generals to leave behind them enor- mous forces to guard strategic passes over or through topo- graphic obstacles, to mask fortresses which, like Maubeuge, guarded valley routes into France, and to rebuild bridges over marshes and river trenches. The retreat brought the enemy into the plateau country of the Isle of France, where THE INVASION OP FRANCE 33 the east--\vest gorges would impede the advance, and where the final struggle would take place with these obstacles in the enemy's rear, hampering his supply system and threatening his retreat in case of disaster. Swinging west through Belgium and south into France, Von Von Kluck, with the main striking arm of the German forces, ^'veloping had, by the first week in September, traversed the level plain movement almost to the gates of Paris. The time had now come, in the plain opinion of the German high command, for Von Kluck to ignore the small French forces to the west and the ex- hausted British Expeditionary Force in front of him, and to strike boldly southeast, get in behind the Allied line east of Paris, and envelop it by a flank attack. The Allied center was already bent in dangerously, and might be broken at any moment. There followed that spectacular sweep of Von Kluck's army from the northern gates of Paris east and south across the Marne, a movement which surprised and puzzled those who looked for no check until the city itself was in German hands. But the destruction of the French army, not the mere occupation of the French capital, was the ^ logical goal of the German General Staff; and this goal could only be reached by the envelopment of the enemy's line. This enveloping action was now fully under way. The moment had arrived for the French to strike their The French blow. Within the circle of the Paris forts, and to the jj^ove west and south of the city, a new French army, the 6th Army, had secretly been assembled. Waiting until Von Kluck had crossed over to the south side of the formidable Marne trench, still patiently waiting until he had also placed the trench of the Grand Morin in his rear, the French 6th Army at length fell on the thin screen of troops he had left west of the Ourcq to protect his flank, and began the process of cutting the lines of communication in his rear. Under pressure the German screen fell back slowly toward the 34 TOPOGRAPHY AND STRATEGY IN THE WAR trench of the Ourcq, where they might hope to find pro- tection for a stand against the superior French forces. The army which was seeking to envelop the Allied line, was itself in grave danger of being enveloped. At this point the Germans showed marked skill in turn- # Ah''- '■',::,-""■'■"■>' '•', ."m>" '"'vmv '' ■ ''.->'ii/ ,11 I ""',,1 , "*. Figure 3. Approximate German positions at the battle of the Marne. Solid line open rectangles: Mass of German armies south of Grand Morin, thin screen of troops facing west to protect right flank, at beginning of battle. Broken line open rectangles: Rearguard defending passage of the Grand Morin while bulk of troops are being shifted north to meet French attack on flank. Black rectangles: Main army facing west and seeking to envelop north end of French line, while screen of troops defends crossings of the Marne trench. Black dots: German armies withdrawing up the valley of the Ourcq. Defensive ing the obstacles, which might have hampered their retreat, the Grand i'lto defensive barriers against the Allied pursuit. How far Morin / tiiig -^ag (jyg iq failure of the British to press Von Kluck valley . . ^ With unrelenting vigor cannot now be stated, but the fact THE INVASION OP FRANCE 35 remains that he was able to withdraw his forces north of the Grand Morin, leaving a rearguard of troops along that trench to hold the pursuers at bay, while he sent the bulk of his forces back north across the Marne to retrieve the dis- aster threatening his exposed right flank. Facing west and southwest against the French 6th Army, Von Kluck began to drive them back. In this new position his left flank was exposed to the British, with only the thin rearguard along the Grand Morin to serve as a protection. For precious / hours the Germans tenaciously kept this steep-sided, flat- floored trench between themselves and their foe, while Von Kluck was redressing the balance farther north in favor of the invaders. At length the British forced the crossings of the Grand The battle TOT i"nf* Morin and the German rearguard fell back to the Petit Marne Morin ajid then to the main great trench of the Marne. *''^n<='i For a short time this trench now became the most important factor in the struggle. If the German rearguard could hold it some hours longer Von Kluck would be left unmolested to destroy the French 6th Army with his superior forces, the Allied line would be turned, and the war won by the efficiency of a militaristic autocracy. If the British forces could cross the trench without delay they could roll up Von Kluck's left flank and decide the battle, perhaps the war, in favor of the Allied democracies. Great issues hung in the balance along that natural moat on the afternoon of Sep- tember 9 th. Nature gave a clean decision to neither contestant. The T'^e cross- obstacle was not sufficient to hold the British in check long Marne enough for Von Kluck to complete the destruction of the French 6th Army. On the other hand the British found it impossible to cross the barrier at once and involve Von Kluck's flank in disaster. According to reports they nego- tiated the obstacle first toward its eastern end where it is A 36 TOPOGRAPHY AND STRATEGY IN THE WAR Terrain at the St. Gond marsh Deadlock at the marsh of smaller dimensions, and only later crossed its western reaches. The delay gave Von Kluck opportunity to swing his right flank back toward the Ourcq and withdraw it up that valley, so as to face more nearly south toward the on- coming British. At this moment there was in progress farther east a phase of the Battle of the Marne in which natural topographic barriers were playing no less important a role than in the operations just described. If the reader will turn again to the diagrammatic sketch, opposite page 4, he will see that the Petit Morin rises in the long east-west belt of the St. Gond marsh, and flows directly west through its gorge in the Marne plateau. We thus have an east-Avest barrier of no mean importance consisting of a marsh at one end and a river gorge at the other. It was along this barrier that the Battle of the Marne, and hence the issue of the war, was finally decided. While the British were struggling to cross the trenches of the Grand Morin and Marne farther west and assault Von Kluck's flank, the French and German forces faced each other across the St. Gond marsh and the Petit Morin gorge. By September 8th or 9th the French had been able to dislodge the Germans from the north side of the gorge, west of the plateau scarp, and drive them northward in hurried retreat. At the Marne the German armies paused, expecting to check their pursuers with the aid of the im- posing river trench ; but the impetuous French assaults car- ried them beyond the northern wall before German rein- forcements could be brought up to hold the advantageous position. Farther east, however, the battle line curved southward and at the east end of the Petit Morin gorge and along the marsh the opposing forces were, for a time, deadlocked. French efforts to push northward across the gorge and occupy the heights beyond were checked, Copyright by Underwood & Underwood. First line of east-facing escarpment east of Paris, covered with vineyards. The view is taken near Epernay. The marsh of St. Gond at the foot of the first escarpment. The few routes through the marsh were rendered impassable by destroying the bridges. K THE INVASION OF FRANCE 37 while the marsh remained practically impassable for both armies. Then began the final German attempt to smash through Exile of the French center. The assault progressed successfully maMh"hi across the dry ground beyond the east end of the St. Gond the. battle marsh, but back of the marsh and Petit Morin gorge the Marne French line held firm. To increase the force of the blow farther east the German armies north of the marsh were seriously depleted. At the same time the German line in this vicinity may have been stripped of men to assist Von Kluck out of his troubles farther west. The difficult nature of the marsh was relied upon to protect the weakened Ger- man line. The French commander, General Foch, saw his opportunity. A thin screen of German troops behind the marshy barrier might, indeed, hold that part of their line secure. But Foch could strike with effect close to the east end of the marsh, where a strong German army connected with the thin line back of the obstacle. This junction was a point of weakness, especially when southward progress of the German offensive left an opening here which the de- pleted forces north of the marsh were unable to close. Here Foch struck with all the fury of the proverbial offensive power of the French army. To get the men for the stroke, he withdrew an army corps from behind the Petit Morin gorge, near the edge of the plateau, where the difficult nature of the topography made the withdrawal comparatively safe. The stroke was a brilliant success. The French armies smashed through the gap. The German center was broken, and the German retreat to the Aisne began. The Battle of the Aisne The great trench of the river Marne is the most imposing topographic barrier in the plateau of the Isle of France. We should expect that behind its protection the German 38 TOPOGRAPHY AND STRATEGY IN THE WAR German failure to halt at the Marne trench Terrain of the Aisne valley i armies in retreat would make a desperate effort to halt their pursuers. Such, indeed, was the case. But the Marne trench was too close to the field of battle; it was, in fact, as we have seen, involved in one of the principal actions at the west. There was no space to manoeuver, no oppor- tunity so to order the retreat that the retiring forces would arrive at the barrier in such dispositions as would enable them to align themselves along the northern bank without confusion before the pursuers could break across at one or more points and flank them out. The British forced a crossing east of the mouth of the Petit Morin and the French broke through farther east, at a time when the Germans had retired north of the Marne near Meaux, and were still far south of it in the direction of Epernay. The German line crossed and recrossed the barrier, instead of paralleling it on its northern side. Desperate efforts were made to hold the trench in different sections, but here the French or British broke over with an impetuous assault, there the secure positions wer6 outflanked by crossings made elsewhere. The retreat continued, and the whole valley of the Marne passed into French hands. Northward there is not a single continuous trench from east to west until the valley of the Aisne is reached. Here, however, is a military obstacle of capital importance. Enter- ing the plateau by a gateway near Eheims, the river flows directly west to join the Oise at Compiegne. For forty miles the great, straight trench cleaves the plateau, its steep walls leading abruptly down to a flat floor several hun- dred feet below, over which the narrow but deep river pursues its meandering course through grassy meadows. In the edge of the plateau above are extensive quarries and vast subterranean galleries and chambers, left by the excavation of a limestone much used for building purposes. Patches of forest clothe the valley walls and are scattered over the up- 60 3 rf s o '3 Ph j3 THE INVASION OP PRANCE 39 land surface. It was a foregone conclusion that the Ger- mans would make every effort to stop their retreat along this natural defensive barrier. About the 12th or 13th of September the main German armies arrived at the line of the Aisne, closely pressed by ^^l^'^^ the French and British. Crossing to the north side the halted at Germans destroyed the bridges behind them, and turned trench""^ to pour a hurricane of steel into the valley. From trenches ■■■".'V.-, '■'^'(^i*::- ^-^,v^%*~ Ri?)EIMS ^'...4,-..» Figure 4. Trench of the Aisne River. along the valley walls and on the plateau crest, from open quarry and cavern mouth, from every bit of woodland cover, machine guns and artillery rained death upon the meadows below, where in exposed positions the French and British pursuers worked feverishly to build pontoon bridges and rafts with which to cross the unfordable river. Heavy rains had been falling and the flood waters made the task doubly difficult and dangerous. Every advantage of Nature lay with the invader. If he could not stop the pursuit here and^ hold the rest of northern France in his grip, he could hardly hope to pause again till the hills of the Ardennes had been reached. From Soissons west to the Oise valley the French crashed French against the barrier with an impetuous assault which carried British them through the hail of steel and over the flooded Aisne. efforts to cross xnc At the foot of the northern valley wall they paused to regain Aisne r/ 40 TOPOGRAPHY AND STRATEGY IN THE WAR Allied failure to breach the Aisne barrier their breath. East of Soissons to Berry-au-Bac, the British met with less success. Baffled at first by the combined de- fensive of Nature and man, they at length made a few pre- carious crossings. The morning of September 14th found the French over the stream and ready for an attack upon the steep northern wall of the trench ; while the British had attained the northern bank only in places. The situation was not ideal for a further offensive, but time was preciouS; the odds were becoming greater every hour as the Teutons dug in more and more firmly along their naturally strong position. An immediate assault on the plateau was ordered. Up the steep valley walls, and out over the plateau to the north swept the invincible Frenchmen, l^ight found the trench of the Aisne behind them, although the highest crests on the plateau were yet in the hands of the Germans. Far- ther east the British were still held at bay south of the trench for several-mile stretches east of Soissons and again east of Bourg. The French, unsupported by a cor- responding British advance on their right, and with their lines of communication imperiled by a flooded river in their rear, were unable to hold their gains. In a day or two they were pushed back to the river, and the Battle of the Aisne was decided in favor of the Germans. The great moat, made formidable by Nature and skilfully fortified by man, had proven too much for the offensive power of the Allied armies. The mobile war in the west was ended, and the war of the trenches had begun. CHAPTER IV THE DEADLOCK The Battle of Nancy While the sweeping movements involved in the Battle Terrain 'of the Marne were in progress in the west, the war of fixed "Grand positions was beginning farther east. The Germans massed Couronne' in the Lorraine gateway were making their first great at- tempt to smash the outer line of the natural defenses of Paris. As can he seen from the sketch opposite page 4, Nancy guards a double gateway through the easternmost plateau scarp. The crest of the escarpment, a line of heights overlooking the lowland to the east, is known to Prench military writers as " le Grand Couronne." Along this crest the main positions of the French armies, uinder General Castelnau, were located, taking skilful advantage of a topog- raphy extremely unfavorable to the Germans. To defeat the French armies and capture the first plateau belt with the JSTancy gateways, was the object of the Battle of the Grand Couronne, or as it is popularly known, the Battle of Nancy. JSTot far from 400,000 highly trained German troops were Assaults massed on the lower land in the course of the battle, and the escarp- hurled against the wooded plateau scarp. French infantry meit in greatly inferior numbers intrenched along the higher levels, and French artillery concealed in folds of the undu- lating upland ground, in ravines cut back into the escarp- ment face, and in patches of woodland, poured their com- bined fire upon the assaulting columns below. In front of the main scarp are outlying mesas and buttes, erosion rem- 41 42 TOPOaHAPHY AND STRATEGY IN THE WAR The im- pregnable barrier Hants which, like the positions on the main crest, command a wide field of fire. Wave after wave of the grey-clad in- vaders in mass formation swept up the lower slopes of the Grand Couronne, withered away under the merciless hail of steel from the heights above, ebbed back to the lowland again in weakened currents, leaving a gray mark on the plateau face to mark the highest reach of each impotent wave. Day after day the slaughter went on throughout all the first third of September. The myth of German invincibility died hard ; the impregnability of Nature's best fortifications, when manned by Frenchmen, was a hard lesson to learn. Forty thousand German corpses at the base of the scarp, one-fourth of the attacking forces on the casualty lists ; such were the results of the Kaiser's introductory study of the natural defenses of Paris. Not, however, until he had pon- dered the bloody chapters of Verdun did he fully realize that the topographic barriers, which he well knew to be diffi- cult, were, as a matter of fact, impregnable. First as- sault on the Verdiin- Toul scarp The Battles of Verdun On the 20th of September the German armies made their first serious attempt to break through the Verdun-Toul escarpment. The French line, pivoting on Verdun, swung far to the south on either side. If the eastern limb of the salient, along the plateau scarp, could be broken, the troops defending the western limb would be taken in the rear and Verdun isolated. The eastern limb was held by a compara- tively thin line of French troops who depended upon the strength of the topographic barrier to maintain their posi- tions. Occasional permanent forts along the crest added their measure of strength, although the known weakness of such fixed points had led the French to transfer many of the THE DEADLOCK 43 big guns to outlying field fortifications located with regard to the favorable configuration of the terrain. From the low plain of the Woevre the waves of German Relation troops were hurled westward against the escarpment. The to th"saii slaughter was terrible, but for a moment German hopes ran ^lihi^l high. Some miles south of Verdun the scarp is broken dovm by erosion, and through several low passes one may quickly reach the Meuse Eiver. Here the Germans secured a foot- hold on the eroded plateau, and brought their heavy artil- lery within range of several of the southern forts. Fort Camp des Eomains quickly crumbled to ruins under the rain of heavy explosive shells. The Germans crossed the river and established themselves in St. Mihiel. A general assault on the long escarpment had succeeded at the point topo- graphically most favorable to the attacking troops, but had failed elsewhere. There resulted the famous " St. Mihiel salient," which was to persist through several years of strenu- ous warfare. The partial success of the German armies could not be pushed to victory so long as the more formi- dable positions of the plateau scarp remained in the hands of the French. The struggle which will go down in history as " the Battle Plan of of Verdun " was not to begin until some months later, when tattle de- the opposing armies had been long deadlocked in the war of t*'""??"^'^ the trenches. Struggles, which in previous wars would have terrain counted as important battles, had shown that Verdun could not be taken except by military operations conducted on a colossal scale. On such a scale Germany prepared for her greatest effort of the war. The accumulations of munitions, and the massing of men and guns exceeded anything pre- viously dreamed of. The main attacks were made from the north. Entering the escarpment by the broad open gateway cut obliquely through it by the Meuse River north of the city, the German armies had already spread out on both sides 44 TOPOGRAPHY AND STRATEGY IN THE AVAR Germany's failure Natural defenses of Verdun of the valley, occupying cross ridges between some of the east-and-west trending branch ravines. An advance south- ward across these successive ridges was deemed more feasible than an attack from the east against the main scarp, although operations from that direction should accompany the major movement. It is not necessary to repeat the history of the great Ger- man disaster: the surprise attack from the north with much ground gained the iirst day; the slower advance of the days that followed and the eventual capture of a few northern forts; then the deadlock with week after week of incessant slaughter of the attacking waves, first on one side of the river then on the other ; the withdrawal of the French to the base of the scarp when German guns on the heights farther north dominated their positions in the Woevre plain; thfe failure of the Germans to ascend the steep scarp ; finally the smashing French counter offensive, in the form of sledge- hammer blows at long intervals, each blow sending the in- vaders reeling back to the north ; half a million of Germany's finest troops sacrificed in the fruitless endeavor to capture the Verdun gateway and conquer the second easternmost belt of the natural defenses of Paris. The French victory at Verdun was not won by the per- manent fortifications. These had been stripped of their great guns in order to enable the French to hold the favor- able topographic positions farther out from the city. The plateau scarp is of limestone, and quarry openings and caverns played their part in the defensive scheme. But most important of all were the east-facing escarpment, and the endless series of east-west ridges with their intervening parallel ravines, draining toward the Woevre plain on the east or into the Meuse River on the west. Dead Man Hill and Pepper Ridge, Hill 304 and the Cote de Talou, now historic points on the map of France, were formerly un- THE DEADLOCK 45 important ridges, lost in the maze of similar crests wKieh characterize the dissected plateau belt. Their defensive value lay in the fact that each crest dominated a ravine next '^'^lt.,#'^::a %t\^'^ ^'ifii ■^'^"/, ;,_--,|i»_^,- ■^//.■^..-■s? Figure 5. Terrain of the Verdun district. north across which the Germans must advance in their assaults toward the south; and in the further fact that in the maze of ridges artillery positions could be found which commanded practically every avenue of German approach. 46 TOPOGRAPHY AND STRATEGY IN THE WAR The Meuse barrier Marshy plain of the Woevre Another topographic element of great importance in the defense of Verdun consists in the peculiar character of the Meuse valley. The trench of the river is hroad and flat- floored, and in wet seasons interposed a marshy and muddy barrier between the two wings of the attacking Germans. The shifting of troops from one side of the river to the other was not an easy manoeuver, and attacks made from one side of the barrier could not always be effectively supported from the opposite side. The Meuse Kiver, moreover, occupies what is known to the geographer as an entrenched meandering valley. From the upland spurs projecting into each curve French guns could dominate the crossings of the river in three direc- tions, and pour their fire upon the German positions on the upland beyond. The successive swings of the valley north of Verdun cause the river to form a valuable de- fensive screen which the Germans would have to cross at repeated intervals, unless they chose to avoid the obstacle by concentrating their movements east and west of the river zone, thereby presenting better targets for the French ar- tillery. German troops once in possession of the meander spurs have sometimes found themselves in a natural trap. On more than one occasion a swift French counter stroke has been so planned as to sweep across the neck of the meander spur, thus imprisoning large bodies of German troops on a peninsula surrounded on three sides by an un- fordable stream. It was by this manoeuver that the French made their largest captures of German prisoners. Attacks on Verdun from the plain of the Woevre were, as already noted, of importance during the main great battle. Determined assaults from this direction would have been highly important, had the nature of the terrain offered any hope of success. But the Battle of Nancy and the first at- tacks from the Woevre had demonstrated the formidable THE DEADLOCK 47 character of the great plateau scarp. Furthermore, the plain of the Woevre in winter and early spring, the time when the great struggle was at its height, is practically impassable for large bodies of troops. The soil is a stiff clay which when wet turns minor roads and fields into bogs, while the water resting on its impervious surface forms marshes and ponds without number. Troops and artillery confined to the few good roads of the district would be at the mercy of the French guns, and could not manoeuver into positions offering any hope of a successful offensive. The plain of the Woevre and its dominating plateau scarp by forcing the Germans to attack from the north, and the ridges and valleys of the plateau by offering defensive barriers which the Germans could not overcome, saved Verdun to the French. The Battles of Flanders Why the German General Staff should elect to make sev- German eral of its main efforts to break the Allied line on the low reaeh\he plain of Flanders is a question which cannot be answered Channel with assurance until after the war. Perhaps it was believed that the weakness of the Belgian and British forces defending this line would more than offset the difficult nature of the terrain; that the Allies might count too much on the pro- tection of Nature, and insufficiently support the line. How- ever that may be, in the early months of the war the world was treated to the spectacle of enormous masses of German troops being sacrificed in the hopeless endeavor to break through this line to the Channel ports beyond. We have seen that the plain of Flanders is low and wet ; so low that the waters of the sea must be diked out at high ^j^ejrsdn of tide, and so wet that an endless system of ditches must be f^^ the constructed to drain the marshy soil. Elvers must have their Channel waters confined by artificial levees, and canals of formidable 48 TOPOGRAPHY AND STRATEGY IN THE WAR depth and width add their defensive strength to the naturally difficult terrain. Against such a barrier the German troops were thrown in great numbers. Fully exposed on the nearly treeless surface of the plain and checked at every step by water and marsh, the waves of German infantry worked painfully forward to melt under the Allied fire. Thousands were drowned in the rivers and canals, while tens of thousands perished on the marshy plain. Still the assaults continued, and forced the defenders to yield, bit by bit, the difficult ground. When nothing else would stop the invaders, the dikes were opened and the whole lower course of the Yser turned into an im- passable lake. So ended the Kaiser's best efForts to plant his guns on the edge of the Strait of Dover. The marshes of Flanders were as impregnable as the plateau scarps of the east. It is not possible within the limits of this volume to trace Summary in detail the influence of land forms upon all the battles of the great war. That is a task which would require several volumes of the present size. The writer's effort has been rather to show how far such an influence still persists under modern conditions of warfare, and to give, in addition to some special examples of this influence in particular bat- tles, such a general picture of the terrain in the chief thea- ters of operations as will serve as a basis for more detailed studies of other engagements. For this reason we must forego, for the present, any analysis of the important role performed by the marshy valley of the meandering Somme in the battle to which that stream has given its name ; of the nature of the topographic obstacles known as Vimy ridge and Messines ridge, and the part they played in two great British victories; or of the chalk ridges of the Champagne plain, and many other topographic features which have given a special character to different contests along the far- THE DEADLOCK 49 flung western battle line. It will be more profitable to turn our attention to the Eastern front for a time, and see how far the nature of the terrain has controlled plans of cam- paign and movement^ of armies in that theater of war. CHAPTEE V THE EASTEEN THEATEE OF WAE Elements of terrain in eastern Europe The vast expanse of territoiy over which the Eussians have battled against the Germans can with difficulty be presented to the eye in a single diagrammatic view. JSTever- theless it will materially aid us in following the eastern campaigns if we attempt some sort of graphic representa- tion of the terrain. This has been done in the accompany- ing illustration (Fig. 6), which shows all except the ex- treme northern and southern limits of the Eussian line when it attained its greatest extension. It will readily appear that the topography covered by the military operations may be divided into four sections : the mountainous belt of the Car- pathians on the south; a broad belt of plateau next north which terminates in an irregular but prominent northward- facing escarpment ; a vast stretch of level plain extending from Germany through Poland to central Eussia ; and the hill and lake country of Prussia bordering the Baltic Sea. We may conveniently consider these four elements of the terrain in the order named. The Car- pathian ridges The Carpathian Mountains Across the southern border of the area the Carpathian Mountains curve eastward and southeastward in a great arc. In the middle portion of their course they consist of a belt of much dissected folded mountains, sixty miles wide, in which long parallel ridges of resistant sandstones remind an American of the folded Appalachians, while 50 ■ "^ Os/erocfe\ -'S^^^^^^-O ,,1/ ■\ /»"■'■■ / A/I '^s'tss a~) '' — " ( / Sreslau % J^ At ,^S-_-:;^^^_X i;^v " ' . -- ^ - ~ ^^^ ... Budapeg. __^ ^- ^"^ Figure 6. Diagrammatic view of the eastern theater of war, showing the Carpathia of Poland, the hill and lake country of East Prussia, the river trenches and marshes, influenced military operations in the east. < -^ ■ im III Key to place names : 1 iJl A, Allenstein; '^i ffli B, Biala; '=s/p-_,2__j>^^ / C #'/ ^'■' Bromberg; -^«> ,, / ATffr=^ . C l/ill ^> Debica ; ■"^^""^^^i^ \ ^ " ^^''^jfi °^' Urohobycz ; ^^^'^^^^-l -^ /« Du, Dunajec; &SC. U ^> Grodek; J, J6zef6w; l(ff/ Le, Leczyca; Lo, Lowicz; P, Piontek; R, Eaba; Rz, Rzeazow; 8, Sejny; Tn, Tannenberg; Tw, Tarnow; W, Wialok; Wa, Wisloka. ountains and their chief passes, the plain )ther features of the terrain which have THE EASTERN THEATER OF WAR 51 streams have eroded parallel valleys on the weaker beds. The parallelism of topographic elements is most pronounced along the northeast side of the belt; and the Carpathians differ from the American system in being more massive along the southwestern side, where crystalline rocks appear, while a somewhat irregular crest line of greater altitude separates the two dissimilar areas. Like the American ridges, those of the Carpathians are well forested. No rivers cut across the crest line in this part of the strategic range, but half a dozen fairly accessible passes, from 1,200 P^^^^^ to more than 2,000 feet high, permit roads and railroads to cross from the low plain of Hungary on the southwest to the plains of Galicia on the northeast. Among these we have heard most frequently of the Dukla, Lupkow, and Uzsok passes, because of their peculiar strategic importance. Along the northeastern base of the Carpathians we may note the location of three cities: Jaroslaw and Przemysl near the center of the arc, two important fortress cities, access to which from Hungary is commanded by the three passes just mentioned; and Cracow, another fortified city near the head of the Vistula valley, whence easy gateways open into Austria and by way of the Oder valley into Silesia. Many rivers flow northward and northeastward from the Eiver Carpathian crest across the parallel ridges and the Galician of the Car- plain. Among these transverse streams, the Eaba, Dunajec, pathians Biala, Wisloka, and Wislok have fairly open valleys through- out their middle and lower courses in the mountains, and have developed good meanders on the valley floors. The San is the most easterly of the important streams which enter the Vistula, and has an entrenched meandering course until it leaves the mountains at Przemysl to turn abruptly northwest past Jaroslaw as a sluggish river meandering ex- tensively on a broad marshy flood-plain, slightly trenched below the level of the Galician plain. To the southeast the 52 TOPOGRAPHY AND STRATEGY IN THE WAR Piedmont plain DiflSculties of the Car- pathian terrain remaining transverse streams flow in parallel lines to the Dniester, whose upper course meanders on a very broad flood- plain which is even more swampy than that of the lower San ; while farther down the river is the deeply entrenched Dniester gorge. We should expect that the streams which debouch from the mountains would deposit some of their load of debris and thus tend to build up an alluvial piedmont slope in- clining gently away from the mountain base. The topog- raphy suggests the presence of such an inclined alluvial plain; but it is evident that its formerly smooth surface has been much dissected by later trenching of the stream courses, and the extent to which the older beds are masked by the alluvium is not clear. The Dniester and San appear to have had their courses determined by the intersection of this northeastward sloping piedmont plain with another southward or southwestward sloping plain described below. It is clear that the topography of the Carpathians must present a serious obstacle to any advance upon the Hungarian plain by the Russian armies. The parallel ridges are so many giant walls of solid stone erected by Nature against an invader. Each intervening valley is a moat difficult to negotiate under fire from the ridge beyond. The only gate- ways through the walls are narrow water gaps through which the outflowing rivers escape. Roads and railways must converge to the comparatively few passageways of this type, where the invading armies would be certain to encounter vigorous resistance, with all topographic advantages in favor of the defense. Beyond the parallel ridges are the higher and more complex mountains of the main range. Here practicable passes are few and far between, those carry- ing railways averaging more than fifty miles apart. In- vading columns would have to operate far apart, and co- operation between them in a mountainous region would be Axiji jiiA»i.tiKN THEATER OP WAR 53 extremely difficult. Transportation of bulky supplies and heavy artillery over the few good roads would be a serious problem. Both roads and railways could be rendered useless by the defenders in a district where high bridges over wild mountain gorges and tunnels through ridges may be effec- tively destroyed beyond possibility of speedy repair. Winter snows would block the passes and rains and melting snows flood the mountain streams. The curving form of the moun- tain belt would enable the defenders to operate on the inside of an arc and reinforce any threatened point more speedily than could the attacking forces. In short, the formidable nature of the Carpathian barrier must inevitably impress itself upon every campaign in which it should become in- volved. The Podolian Plateau The rocks, which are strongly folded in the Carpathians, Terrain suddenly flatten out toward the northeast and north to form °* ^'l". ■' _ Podolian the more level country of Galicia and Poland. The topog- region raphy is not always that of perfectly horizontal rocks, how- ever, but betrays the presence over broad areas of moderate dips toward the mountains. Thus in eastern Galicia there is an inclined plateau with its gentle back slope dipping south- ward obliquely toward the range, while on the north the steep erosion scarp faces northeast, north, and northwest toward a broad lowland eroded by the headwaters of the Bug and Styr Elvers. This highland is known as the Po- dolian Plateau, and has the same form and origin as the plateau belts of the Paris Basin. The rivers flowing south- ward down the gentle back slope have cut deep gorges, which are remarkable for their straightness and their parallel arrangement. To this system belong the Sereth, the Strypa, Rj^gj. and the Zlota Lipa, formidable military obstacles which have go''ges figured largely in the Galician campaigns. Toward Przemysl 54 TOPOGRAPHY AND STRATEGY IN THE WAR Strategic position of Lemberg Terrain of southern Poland The Cracow- Jaroalaw trench the rocks of the Podolian Plateau appear to change to a southwestward dip, and the steep erosion escarpment bends abruptly toward the northwest. At the base of the escarp- ment, near the angle where the line of cliffs changes from a northeast-southwest to a southeast-northwest direction, lies the city of Lemberg, guarding a strategic gateway or low pass from the Bug lowland through the plateau to the San- Dniester lowland and Przemysl. Farther northwest, Rawa- ruska occupies a similar position. At both points strategic railways cross through the plateau from one lowland to the other. West of the San River the plateau topography is less pro- nounced, but the upland of southern Poland may represent its continuation, with a gentle slope toward the southeast and a poorly developed and very ragged escarpment facing northwest. If this is the case the upper Vistula would appear to flow along the depression formed by the intersec- tion of the southeastward slope of the plateau and the north- ward slope of the Carpathian piedmont plain, just as the San and Dniester Rivers flow in opposite directions along the depression of similar origin farther east. The surface of the south Poland plateau is a forested upland, having an average elevation of nearly a thousand feet over broad areas, and dissected by deep stream gorges which make the coun- try difficult to traverse. It is complicated by a broad uplift in the Kielce district which brings older rocks, containing valuable mineral deposits, to the surface and forms the heights of Lysa Gora rising far above the general level. Between the western continuation of the Podolian Plateau and the northern base of the Carpathians is an east-west lowland of capital strategic value. In form it is a broad shallow trench, occupied by no single river, but rather by branches of several streams, including the headwater portion of the main Vistula River. At the east the lower Wislok THE EASTERN THEATER OP WAR 55 follows the trench for twenty-five miles before joining the San, while large branches of the Wisloka flow eastward and westward through it to join the trunk stream. Through it also passes the main railway line connecting Bukharest and the Black Sea with Berlin and western Europe. Protecting the eastern entrance to the trench, just where the railway enters it, stand the fortresses of Przemysl and Jaroslaw; at its western end is the great ring fortress of Cracow. The Plain of Poland North of the Podolian Plateau and its westward continua- Terrain of tion in south Poland stretches the monotonously level plain ^^® P'*^" of central and northern Poland. Here the strata of recent geological age lie horizontal, and the only topographic fea- tures of importance are the river valleys. As the plain sur- face is usually but 300 or 400 feet above the sea, the rivers cannot cut deep trenches ; but they have widened their valley floors, and meander extensively over the broad flood-plains deposited during periods of high water. Floods result from heavy rains in the Carpathians or from ice dams along the lower courses of the streams. The principal river is the Vistula, which from the junction of the upper Vistula and The San flows in a broad shallow trench northwesterly through trench the Polish plain into Prussia, where it turns sharply north- ward to the Baltic. A majestic river of great volume, un- fordable and seldom crossed by bridges, subject to terrible floods which may cover its entire valley bottom, it forms one of the most serious military obstacles in Europe to an enemy which would cross it ; but a magnificent waterway, navigable for large vessels from the San to its mouth, for armies which are able to use it as a line of communication. Warsaw is located on a terrace 120 feet above the level of the stream, and therefore safe from damage by th? floods, 56 TOPOGRAPHY AND STRATEGY IN THE WAR River and marsh barriers Brest Litowsk Glacial to- pography Abandoned river valleys Chief among the tributaries to the Vistula is the Bug, itself a stream of good size. Its upper course flows for miles through a swampy flood-plain, the main current seldom approaching close to the dry banks. As this part of its course runs from south to north, it opposes a difficult barrier to troops moving east or west. Where the river begins to turn westward is the Russian fortress of Brest Litowsk, surrounded by low marshy lands which can readily be flooded to prevent an enemy from approaching the fortress walls. The Narew River is likewise bordered by almost impassable marshes which continue northeastward past Augustow to connect with the ISTiemen trench, thereby completing a con- tinuous topographic barrier extending from the lower Dniester gorge along the upper Dniester and San marshes, down the Vistula to Warsaw and up the Narew to the Niemen, thence down the Niemen to the sea. Every part of the barrier thus described has played an important role in the fighting in the east. The greater part of the Polish plain has been glaciated, the ice sheet having reached nearly as far south as Lemberg. A mantle of glacial soil covers much of the area, and has greatly disturbed the preglacial drainage. In the obstructed valleys, lakes and swamps are common, and extensive areas of marsh characterize the undrained surface of the faintly undulating glacial deposit. Where the plain continues un- changed into Russia proper, we find the famous Pripet River swamp, a vast labyrinth of marsh, bog, and sluggish rivers. When the edge of the great glacier lay on the Polish plain, rivers flowing toward it were blocked by the ice sheet and compelled to flow along its margin until the barrier melted away. The marshy channels of these temporary river courses form an interesting element in the plain topography. North of Lodz one of these channels continues the course of the Bzura River westward into the drainage of the Warta, Paul Thompson Typical view of the Polish plain near Lodz. The motor car was destroyed by a bomb from an aeroplane. Patil Thompson. German soldiers advancing toward Warsaw across the level surface of the plain of Poland. THE EASTERN THEATER OP WAR 57 and, as we shall see, played a significant role in the great battle for Lodz. At Bromberg on the Vistula another of the channels runs westward along what was the temporary glacial course of the lower Vistula River. Aside from the obstacles to movement over the plain Absence of formed by the river trenches and marshes, it is necessary to ^froad* remember that rocks underlying the plain surface are of construc- recent date and unconsolidated. Accordingly they furnish no materials suitable for road construction. In a region where extreme flatness preventing ready runoff of rain water, broad expanses of permament marsh interrupting traflic, and a clayey soil forming a tenacious mud when wet, create a pressing need of good roads, there exists no material from which such roads may be made. Moreover the popu- lation is scattered and poor, and tempted to rely on river transportation in summer and transport by sleds on the frozen rivers in winter, instead of improving the roads. Eail- roads are few and good wagon roads almost non-existent. Military operations on the plain of Poland must, therefore, encounter difiiculties of considerable magnitude, especially in winter when the roads become mired with snow and mud. " In Poland," said Napoleon, " I have learned of a fifth element — mud." The Hill and Lake Country of Prussia The great ice sheet halted long enough in what is now Morainic East Prussia to have accumulated along its fluctuating mar- ^^rain of gin a " moraine " or ridge of glacial debris of impressive Prussia proportions. A score or so of miles in breadth, the morainic belt attains an altitude of 500 to 1,000 feet. It is noted for its intricate network of marshes and lakes, which culminate toward the east in the Mazurian Lakes district. The whole morainic country is an endless maze of irregular hills covered 58 TOPOGRAPHY AND STRATEGY IN THE WAR Difficul- ties of the East Prussian terrain with wild, uncultivated areas of barren sandy soil, alternating with swamps, lakes, and forests. From the vantage point of some higher hill one gains the impression of a gloomy waste of country, partially clothed with woodland areas of birch and pine, and dotted with thousands of ponds, marshy swales, and irregular lakes. Eoads and railways must fol- low the intricate defiles or narrow land bridges between the bodies of water and swamp, and to any but those who know it best, the region is a wilderness of monotonously similar topographic forms. Lyck, Allenstein, Tannenberg, and Osterode lie within this belt. Farther west another moraine reaches the Baltic Sea at Danzig; but the Danzig belt has not figured in the war up to the present time. To an invading army the morainic country of East Prussia would seem to oppose almost insuperable obstacles. The forces would of necessity divide into a number of columns, each threading its way painfully along the narrow isthmuses of dry land and between the rolling hills. Hostile forces would contest the passage of each defile, and from the forested hills hostile artillery would pour its fire on the advancing columns. Compelled to deploy on a battle line, the troops would find their way blocked by ponds and marshes. Some' of the ponds have sandy bottoms and to ford them is easy; but the same troops attempting to cross a similar body of water might suddenly find themselves trapped in a bottom of clay. Many of the marshes are firm enough for the passage of men, but others are treacherous bogs. The lines of communication behind the advancing armies would be few and difficult, and the opportunity for a successful re- treat in case a superior foe was encountered would be com- paratively slight. A secure fastness for the defending troops, a formidable barrier for invading forces, the hill and lake country of East Prussia has contributed an interesting chap- ter to the war in the east. THE EASTERN THEATER OF WAR 59 The Russian Plan of Campaign With the above-described types of topography in mind, let The us consider briefly the general plan of the Russian campaign to^BerUn against the Teutonic allies. At the beginning of the war one ■was tempted to measure the distance from the western bor- der of Poland to Berlin and consider this as the distance Russian armies had to move in order to threaten the German capital. This, however, was to ignore the absolute depend- ence of armies upon thoroughly safeguarded lines of com- munication. It would manifestly be impossible for a large Russian army to concentrate in western Poland and move on Berlin so long as an unbeaten German army occupied the morainic country of East Prussia, and a similar Austrian army existed in the rugged plateau upland of Galicia; for as soon as the advance on Berlin was started, the lines of communication running from Russia through Poland to the army at the front would be in peril from a southward ad- vance of the Germans debouching from the morainic hills, or a northward advance of the Austrians descending from the Podolian Plateau. If either advance succeeded in sever- ing, even for a short period, those arteries which alone enable an army in the field to live, disaster to the Russians would speedily follow. It would be more accurate, therefore, to draw a line from the eastern point of the Prussian border southeastward to the eastern border of Galicia, and consider this as the line from which the Russian advance on Berlin must be measured. This, roughly, doubles the length of the advance. Already in possession of the territory immediately in front The East of the center of this line, the Russians had to concern them- p^Xem" selves with the hostile territory at the north and south. On the north the task was the more serious. Here were combined the most highly perfected military machine and the most 60 TOPOGEAPHY AND STRATEGY IN THE WAR difficult topography. In order to make an advance on Berlin from western Poland feasible, Russian armies must drive the Germans out of all that part of Prussia projecting east of the west Poland border. This would involve not only the traversing of the morainic hill and lake country, but in addi- tion the passing of a very serious obstacle, the broad, shallow trench of the lower Vistula which cuts across the neck of the peninsula of eastern Prussia. The strength of this defensive line lies in the fact that the invaders would have to cross the broad, flat floor of the valley under fire from artillery posted on the crest of the western valley wall, and would also have to negotiate an unfordable river of great breadth and volume ; and in the further fact that each end of this line is guarded by a powerful fortress, Thorn at the south and Danzig at the north. The In several respects the topography in the south favored DToble^ the Russian plans. No topographic barrier along the boun- daries between Russia and Galicia prevents an easy invasion of the latter, whereas the formidable barrier of the Carpa- thians does separate Galicia from the rest of Austria- Hungary. Galicia is, therefore, a peripheral province, which is for topographic reasons peculiarly isolated from the rest of its country and therefore more easily subject to conquest by a neighboring power. During the invasion the deep gorge of the lower Dniester, and farther west the marshy flood- plain of the upper Dniester, would serve as admirable pro- tections for the left flank of the invading army. Once the Austrian armies were pushed westward toward Cracow or southward over the Carpathians, the few passes over the latter could be held by small detachments of troops, and the left flank of the westward-moving Russian army would then have the effective protection of a mountain barrier ; for while several roads and railways cross through the passes, they are so readily controlled that the strategic importance of the THE EASTERN THEATER OP WAR 61 barrier is not greatly diminished. Austrian reinforcements would have to defile through the passes and along the few narrow mountain roads in greatly extended columns, a for- mation which would render them vulnerable to attack by inferior numbers. No sudden assault of serious magnitude upon an army flank which is protected by a mountain barrier is feasible so long as the defending troops properly perform their functions. With these favorable topographic elements was combined Basis the further favorable fact that the Austrian armies were less principal formidable than the Prussian military machine. Political offensive conditions in Austria-Hungary also dictated a vigorous Rus- sian offensive in Galicia, since a nation composed of hetero- geneous elements, some of them held in subjection against their will, can be more easily driven to seek peace after military reverses than can a nation which is better unified. Topographic, military, and political considerations combined, therefore, to induce the Russian General Staff to subordinate the East Prussian campaign to far greater movements in Galicia. CHAPTER VI EAST PEUSSIAN CAMPAIGNS The Kussian advance German victory of Tannen- berg Into the morainic country of East Prussia the Russians launched a vigorous offensive in the first month of the war. Two main armies cooperated in the movement, one advancing from the fortified bases at Kovno and Grodno on the east, the other moving north from the forts along the ISTarew River. Advancing along occasional roads through the hills and forests in a few long-drawn-out columns the Russians in- vaded the home of the Teutons. Before the end of August they had threaded their way through the forests, among the lakes and marshes, and over the rolling hills, always beating back the German defensive, until more than half the distance to the Vistula barrier had been traversed, and a portion of the defeated German forces shut up in the fortress of Konigs- berg. Then two Russian army corps, caught in the mazes of the difficult region near Tannenberg by a successful German manoeuver, were practically annihilated. Von Hindenburg, intimately acquainted with every mile of the morainic land from long study on the ground, so disposed his forces as to cut off every practicable avenue of escape for the Russians except a narrow defile between some of the lakes. Furiously at- tacked and pressed back upon this defile in confusion, the Russians became hopelessly congested at the one exit from the trap. Eighty thousand men were captured or destroyed. The difficulties of negotiating the morainic defensive line in the face of the Prussian military machine had proved too great, and the Russian line fell back. The morainic topography continues across the East Prus- G2 BAST PRUSSIAN CAMPAIGNS 63 sian border into Russia, where, in the region of Suwalki, one finds a country of forested, marshy fenland and lakes, per- haps even more difficult to cross than the region farther west. Terrain especially since roads and railways are less numerous. From suwalki Suwalki eastward to Sejny a narrow causeway through the region marshy forest is the main highway of travel. As the Rus- sians fell back the Germans followed them into this difiicult region. It is interesting to note that the Germans were now confronted with almost exactly the same topographic features which had opposed the westward movement of the Russians. Not only was there a region of hills, forests, lakes, and swamps to be crossed, but beyond lay the valley of a large river, the Niemen, which, like the Vistula, runs from south The ' n • 1 1 Niemen to north across the path of advance. To correspond with the trench fortresses of Thorn and Danzig at the two ends of the Vistula barrier stand the fortresses of Grodno and Kovno at the ends of the Niemen trench. This great topographic barrier was Russia's main protec- Battle of tion against an invasion from Prussia. Behind it, and its continuation in the Bobr and Narew River marshes, the re- treating Russian armies took their stand about September 25th. Against this line the German armies dashed themselves in a vain endeavor to pass over to the eastern side. After a vigorous artillery duel the German offensive waned, the Russians retook the offensive, and there began that pursuit of the German columns back through the marshes and forests to the westward which is known as the Battle of Augustow. Hampered by the broad marshes and few roads, the Ger- mans lost heavily, particularly, it is reported, along the narrow Suwalki causeway. By the first week of October the German line had been pushed back into Prussian terri- tory at the south and nearly to the Prussian border on the north. The topographic barriers of the Suwalki province had in turn proved too difiicult for the German armies. By 64 TOPOGRAPHY AND STRATEGY IN THE WAR Angerapp Eiver- Mazurian Lakes barrier Object of attack on the Niemen- Narew barrier Natural defenses of the Warsaw- Petrograd railroad a slow and painful advance the Russians were able to reach the line of the Angerapp Eiver and eastern side of the larger Mazurian Lakes by November 15th, which excellent defensive line they held for three months, until the sudden arrival of new German forces in February compelled another Russian retreat to the defensive line of the Niemen, Bobr, and Narew. To appreciate the probable significance of this new Ger- man advance, and thus to judge of the extent of its success, we must review certain features of the local geography. The possession of Warsaw had long been coveted by the German General Staff, both because of its strategic importance as a railway center and as a point for crossing the Vistula, and because of the political importance of the Polish capital. To achieve the capture of the city Von Hindenburg had already sacrificed tens of thousands of lives in repeated and spectacular direct assaults from the west. An alternative plan of indirectly reducing the city by severing its communi- cation with the main part of Russia may well have appealed to him in view of the failure of direct attacks. The most direct railway line between Warsaw and Petrograd passes within forty-five miles of the East Prussian border, and to sever this important line of communications would be a long step toward the reduction of Warsaw. Between the German armies in East Prussia and the coveted railway there was first the fortified line of the Rus- sians along the Angerapp River-Mazurian Lakes barrier ; but farther back and far more important was the great natural barrier formed by the Niemen, Bobr, and Narew Rivers with their associated marshes. The north-south trench of the Niemen, protected by the fortresses of Kovno and Grodno at the north and south respectively, has already been de- scribed. Near Kovno the river is perhaps a quarter of a mile broad, and everywhere throughout this portion of its The Niemen River spanned by a German pontoon bridge. Copyright by Underwood & Underwood, Russian troops intrenched on the east bank of the Niemen, firing on German forces attempting to cross the river. EAST PRUSSIAN CAMPAIGNS 65 jRourse is a formidable obstacle. From a short distance west of Grodno the river Bobr flows in a southwesterly direction, continuing the defensive line until it joins the Narew, after Figue 7. Natural defenses of the Warsaw-Petrograd railway. which the barrier consists of the N"arew as far as its junc- tion with the Bug, and of the Bug for the short remaining distance to the Vistula. The Bobr, in spite of its small size, is a very difficult obstacle to cross. Broad marshes flank it 66 TOPOGRAPHY AND STRATEGY IN THE WAR Fortifica- tions of the Niemen- Narew barrier The second German offensive on either side, the belt of wet country sometimes reaching a breadth of many miles. The N^arew is a meandering river of larger volume, bordered by numerous abandoned meander channels or oxbow lakes, and likewise flanked on either side by broad areas of marsh. In order to render this natural obstacle still more formi- dable, the Russians had erected imposing fortifications at various points along the line. The most important were Kovno at the northern extremity ; Grodno at the south end of the Niemen trench, and near the short gap in the barrier which intervenes between the Niemen and the Bohr; Ossowiec on that portion of the Bobr most easily reached from Prussian territory; and Novo Georgievsk at the southwestern extremity of the line. Olita, Lomza, Ostro- lenka, Rozan, Pultusk and Serock were smaller forts erected at intervening points along the river. When one re- members that in addition to the forts, temporary field fortifications and trenches built after the war began had still further strengthened a line already made exceptionally strong by Nature, one can understand why two great German offensive movements broke down when this line was reached. In his second offensive Von Hindenburg seems to have avoided, so far as possible, the morainic belt of hills and lakes, and to have advanced across the more level country to the north and south with a rapidity which would have been impossible in the region of the hills. It was indeed in the morainic region around Lyck that the Russians longest kept a foothold on German soil. It is also noteworthy that some of the largest captures of Russian prisoners made by the Germans in this second advance occurred in the marshy forest at the eastern end of the morainic belt where lake and swamp render retreat more diiBcult. Ossowiec is the point on the river-marsh barrier most easily reached by the Germans, and was besieged both during JiAST i'KUSSIAN CAMPAIGNS 67 the earlier and later German attacks on this line. The only railway between the western extremity of the Niemen-Bobr- ISTarew line and Grodno runs from Lyck in East Prussia to Marshy Ossowiec, and continues southward to the Warsaw-Petrograd ^^'T^l? ,_ mi • 1 < t 3.110. DAS railway. This line enabled the Germans to bring their heavy sieges of siege artillery right up to the barrier they wished to break ^^^"^'^"^ through and to supply the forces attacking the Ossowiec forts. If successful here, they could continue along the railway to break the Warsaw-Petrograd line of communi- cation. Fortunately for the Russians, the natural bar- rier was especially strong in the vicinity of Ossowiec. Broad marshes on either side made it difficult for an enemy completely to invest the fortress. The moving and placing of guns is difficult in marshy land and it is reported that after some of the guns were brought up within range of the forts, they had to be taken farther back to find satisfactory positions on dry ground, especially as a thaw had rendered the marshes more dangerous. Intrenching in a marsh is alpiost impossible ; and heavy siege guns in marshy land are liable to capture by sorties from the fortress if unprotected by well-intrenched infantry. According to report some of the guns intended to reduce the fortress were taken west to the dry ground around Eadzilow for safety, while others were caught in the marsh by the thaw and could not be removed. For a second time the topographic difficulties of the Ossowiec district contributed largely toward rendering the German siege a failure. It would seem that the Germans succeeded in really break- German ing the Niemen-Bobr-Narew barrier at but one point. This 's^ilur^ t° ° _ ^ pass the was just north of Grodno, where German troops crossed to Niemen- the east bank of the ISTiemen in considerable numbers. The ta^rier eastern extension of the Augustow forest, reaching to the river at this point, afforded sufficient protection to the Germans to enable them to force a crossing along 68 TOPOGRAPHY AND STRATEGY IN THE WAR a front some twelve or fifteen miles in length. It should be noted that here the Warsaw-Petrograd railroad lies very close to the river-marsh barrier. The breach was too narrow, however, to permit any extended eastward advance; and failing to widen it, the Germans were forced to retreat. Russian armies, which had taken up de- fensive positions behind the barrier, gradually resumed the offensive, and pushed the Germans back toward the Prussian border all along the line. The German offensive had failed to pierce the railway line behind the fortified natural barrier, and Warsaw was safe for the time. Russian armies had suf- fered great losses during a retreat made more difiieult by bad weather conditions ; but the German losses were likewise very high, and while East Prussia was freed from the invader, the strategic position of the German armies was probably not improved by the advance beyond their own strong de- fensive position on the west side of the river and lake bar- rier in East Prussia. CHAPTER VII EAELY GALICIAN CAMPAIGNS In the Galician field of operations the initiative was first The taken by the Austrians, who launched an offensive northward o^e„giyQ into that part of Poland east of the Vistula in the early- days of the war. With its left flank protected by the barrier of the Vistula and its right in touch with the marshes of the Bug, the Austrian advance on Lublin and Cholm began. Apparently the Russians decided to swing back toward the east and, if necessary, put the barrier of the Bug between themselves and their enemies until the main Russian armies farther south should have delivered their blow; for we find the northern armies gradually retreating on a front becoming more and more nearly parallel to the river. The Austrian advance was short-lived, however, for about the middle of August Generals Russky and Brussilov, with enormous Rus- The sian forces, began their smashing advance into Galicia from offensive the east, thus threatening the rear of the Austrian armies facing north or northeast in Poland. The marshy flood- plains of the Bug River, together with the meandering Bug River barrier course and interlacing channels of the stream, afforded a good first line of defense for the Austrians, from behind which they might hope to check the Russian advance. The marshes were probably more formidable to the invader than was the channel of the river itself; for in negotiating them troops had to " defile " along the few good roads crossing the wet lands in long, narrow columns which offered a good mark to the defenders. It was not surprising, in view of the 70 TOPOGRAPHY AND STRATEGY IN THE WAR Attack on the Podolian escarp- ment Battles for the gateways topography, to hear of fierce fighting along the line of the Bug Eiver and to read in the despatches repeated references to the few towns, such as Sokal and Kamionka, marking the points where important roads cross the wet valley floor. The Austrians now realized, however, that if the advantages of topography were with them, the advantages of numbers were overwhelmingly with the Russians. The passages of the Bug were forced by weight of superior forces, and the defenders began what was to be a long and disastrous retreat. After defeating the Austrians along the Bug, the Russians in their westward advance soon reached the barrier pre- sented by the steep face of the Podolian Plateati scarp where it trends from southeast to northwest. The situation was much like that encountered by the Crown Prince's army in France when it attacked the steep east-facing escarpment near Verdun. In places the Podolian scarp rises five or six hun- dred feet above the Bug lowland, and is often quite pre- cipitous, especially where resistant limestones composed of old coral reefs weather into nearly vertical cliffs. In other places the escarpment is lower, but steep, and may present a nearly continuous wall for many miles at a stretch. Occa- sionally it slopes down more gradually to the plain as a forested hillside, while out in front are numerous erosion remnants in the form of mesas and buttes. Whatever the local nature of the escarpment, it offers a serious obstacle to the troops which must cross the lowland toward it under fire of artillery posted on the crest, and then ascend the steep slope in face of the enemy's fire. The two great battles of Lemberg and Rawaruska were waged for possession of the two strategic gateways through the Podolian Plateau belt. A part of the fighting for Lem- berg took place east of that city, on the long foothill ridges which here extend many miles out into the lowland. The main " battle of Lemberg," however, was fought farther EARLY GALICIAN CAMPAIGNS 71 south, on the plateau upland. As will be seen from the dia- gram, opposite page 50, the direction of the steep escarpment is such that it can be avoided by an army crossing the upland surface south of the latitude of the city, although this army would encounter the successive deep gorges of the parallel streams flowing down the back slope of the plateau to the Dniester. It was Brussilov's army which swept the Aus- trians from this region, although not without bitter struggles at the principal crossings of the larger river trenches. In the final struggle south of Lemberg, as along the escarpment Lemberg farther north to Rawaruska and beyond, the Russians were «■"tdpographic barrier is protected from a flank attack by the Gulf of Eiga and the lower course of the Aa Eiver; at the southeast similar pro- tection is' aiforded by the belt of lakes and marshes south of Dvinsk, forming the continuation of the morainie belt of East Prussia, and by the ' east- west , course of the Dvina Eiver. Seldom has a strategic railway been more securely situated behind natural fortifications. We may divide the campaign for the Eiga-Dvinsk line into jthree parts: first and most important of all, the opera- tional' against Eiga with the object of turning the right of the Eusdian defensive line; second, the attempts to break the line at Friedrichstadt and elsewhere by frontal attacks; and third, the efforts to capture Dvinsk and thus turn the left of the forces behind the river. The assaults against Eiga began with an advance from Mitau along the Mitau-Eiga railway, early in August. About half-way between these two points is the small town of Olai, important to us because it marks the place where repeated German attacks "ended in failure. Immediately north of Olai is the great Tirul marsh ; just south is the Misse Eiver flowing through a marshy forest. One German assault after another failed to pene- trate one or both of these topographical barriers, and the name Olai has thus come to be associated -with costly Teu- tonic defeats with which the town and its artificial defenses had little or nothing to do. German successes in the east were usually achieved through the effective use of very heavy artillery in battering down the resistance of the lighter Eus- sian guns. Wherever marshes restricted the use of heavy intj ijKJiAT KUSSIAN RETREAT 117 artillery to the narrow front offered by a railway embank- ment or causeway through the wet country, Teuton and Slav met on more equal terms, and the Teuton offensive languished. After several weeks of costly but unsuccessful assaults Advance against the marshy barrier from the south, the Germans Tukkum shifted their forces to the west and attacked from the direc- tion of Tukkum. In reports of this fighting the town of Schlock figured prominently, for reasons readily apparent from the map. The lower Aa Eiver makes an effective north-south barrier which has its northern end at Schlock. Here the river turns east and flows parallel to the gulf coast for many miles, as if deflected from its normal course by a broad sandbar deposited under the influence of an eastward moving current in the gulf. South of the deflected river and increasing its value as a barrier is a long narrow lake known as Lake Babit. The Tukkum-Riga railway follows I'ake the bar between river and gulf for some miles before cross- ing the river on its way to Kiga. It appears, therefore, that the north-south segment of the Aa Eiver, reinforced on the east by the Tirul marsh, interposes an impassable barrier to any advance south of Schlock ; while the logical route along the railway would compel the attacking forces to advance in column on a narrow ridge of land flanked on both sides by bodies of water from which or across which Russian guns could direct a deadly flanking fire. Topographic conditions would seem to render impossible any hope of a successful attack against Riga from the west; yet the Germans strug- gled fiercely to capture the city from this direction. The name of Schlock is naturally associated with their failure to penetrate the physical barriers near that town. The naval engagement for control of the Gulf of Riga ended in favor of the Russians and thus assured to their right flank the pro- tection of the sea. 118 TOPOGRAPHY AND STRATEGY IN THE WAR Capture of Pried- richatadt In attempting to break through the Dvina river and marsh barrier the Germans succeeded in capturing Fried- richstadt near the center of the line early in September and may even have thrown some troops over the river to the north bank. This degree of success was favored by the parallel railway close to the river on the south, from which one of the few roads through the marsh connects with the town. But the consummation of the success thus begun was ren- dered impossible because of the obstacles presented by both river and marsh to an advance with front sufficiently broad to make the crossing of the river effective; and because the country north of the river is a marshy forest, largely devoid of roads, through which the troops which may have crossed could make but little progress. The railway last mentioned Jakobstadt bridges the Dvina near Jakobstadt, and the Germans were thus aided in an attack near that town which brought them close to the river, but apparently not to its northern bank. Near tlxkiill several islands in the river afford opportunity for a crossing which would further be aided by the fact that small streams from the south provide facilities for construct- ing pontoons in safety behind the German lines and floating them down into the main river in the shelter of the islands. A heavy bombardment of tJxkiill led the Russians to antici- pate a crossing here, but apparently it was not effected, the unfavorable topographic elements more than counter- balacing those favorable to such an operation. The campaign against Dvinsk failed because of the in- ability of the Germans to get past the lakes, marshes, and streams guarding the southeastern end of the Riga-Dvinsk barrier. Dvinsk is protected in the first instance by a great bend in the Dvina River which forms a natural moat on all sides but the north. Beyond the river to the west and south lie the marshes and lakes often mentioned in the despatches. Sventen Lake Sventen to the west, with its associated marshy forest, Natural defenses of Dvinsk THE GREAT RUSSIAN RETREAT 119 proved a particularly formidable obstacle to many attacks; while the marsh to the southeast checked a flank attack from that quarter. The losses suffered by the Germans in their frequent attempts to storm the passes between the lakes were most serious. Indeed, the terrific but fruitless assaults against the natural fortifications of the whole Eiga-Dvinsk region, covering a period of many months, created appalling casualty lists and materially weakened the chances of the Ger- mans to conduct successful offensive movements in the future. A similar weakening for a similar cause took place at the End of the southern end of the eastern front, where the Austrians and retreaT Germans who had pushed their offensive to the Goryn and Sereth Rivers were later thrown back to the line of the Styr and Strypa, with heavy losses in prisoners as well as in killed and wounded. On the other hand the Russian armies, protected by the troops lined up back of the Dvina-Pripet- Styr-Strypa barrier, secured an opportunity to reform their shattered forces, equip another group from their almost limit- less supply of fighting men, and so confront their enemies in a few months, as strong or stronger than they were in April, 1915, when the great retreat began. It would not be profitable to trace the fluctuations of the Later Russian line since the end of the retreat. For the most part °P^^^ ^°" such a treatment would be but a repetition, with minor varia- tions, of matter already presented. In the south we find the Russians, after their advance to the trench of the Strypa, pushing forward in a new offensive until the Teutons brought them to bay along the middle course of the formidable Zlota Lipa trench. Farther north an advance from the Styr brought the Russian line to the banks of the Stochod, where The their move against Kovel was abruptly halted. This small 1,^^°^. river flows through a maze of marshes and lily ponds bor- dered by a higher bank on the west, from which the Teuton artillery and machine guns comina,nded the difficult crossing. 120 TOPOGRAPHY AND STRATEGY IN THE WAR Despite the most desperate fighting the Russians were unable to make an effective breach in this barrier, and one of their most important offensives was here permanently blocked. In the summer of 1917 another Russian offensive in Galicia was only checked at the Lomnica River by internal disin- tegration of the advancing forces. Even when German in- trigue had successfully employed as its tools the shameless traitors and ignorant dreamers of Russia in a campaign of demoralization which wrecked the fighting power of the great Rusian armies, the influence of topography still mani- fested itself in the south, and we find the fleeing troops first making an effective stand behind the trench of the Zbrucz River on the border between Russia and Galicia. !No more eloquent testimony to the demoralization of Russia's military power could be offered than a mere statement of the fact that in 1917 German armies in the north far weaker than those of 1915 passed with ease the same Riga-Dvinsk bar- riers which proved absolutely impregnable so long as Russian troops formed heroic fighting units instead of radical debating societies. Figure 14. The Italian theater of war, showing the principal mountaii I plateau barriers, river trenches and marshes, aifecting the Italian campaigns. CHAPTER XI THE ITALIAN THEATER OF WAR Italy's Problem In May, 1915, Italy declared war on Austria-Hungary, slow prog- 'here were among the friends of the Entente many who jf^j-"* slieved that Italian armies would quickly overrun the armies )uthward projecting peninsula of Austrian territory known 3 the Trentino, and perhaps sweep round the northern end f the Adriatic and occupy Trieste. When months and even ears passed by, and Italia Irredenta still remained un- edeemed, disappointment was not unmixed with criti- ism of the new ally's apparent inaction. A study of the atural obstacles blocking every path of Italian advance will how that the disappointment resulted from entertaining .opes unduly high, and may perhaps tend to mollify such pirit of criticism as may still persist. The Alps consist of a complex system of rocks intensely Terrain of 'olded and broken, and deeply dissected by stream erosion. ^^^ -^'ps A.mong the rock masses are great limestone formations, in 3laces totaling thousands of feet in thickness, with which we will have particularly to deal. Because the rock masses were raised from ten to fifteen thousand feet above the sea in their higher parts, streams cut remarkably deep canyons and left a country most difficult to traverse. The difficulties were increased a hundred fold when the ice streams of the glacial period flowed down the valleys, cutting them much deeper, steepening the valley walls into rocky precipices, leaving the side valleys hanging hundreds of feet above the 121 122 TOPOGRAPHY AND STRATEGY IN THE WAR floors of the overdeepened main valleys, sharpening the inter- valley ridges into knife-edge aretes, and carving the dome- shaped peaks into jagged needles and horns. The resulting topography was one of indescribable ruggedness, in which precipitous cliffs, inaccessible peaks, steep-sided divides, and hanging valleys present to the engineer almost insur- mountable difSculties. Koads and railways are for the most part restricted to the bottoms of glacial troughs and to the few passes across intervening ridges. Where they are forced against the rocky wall by a lake occupying the trough floor, or lead upward over dissected mountain slopes, tunnels and bridges are numerous. Military movements through such a country must of necessity be slow; the lines of advance are few and narrow, and easily blocked by the destruction of bridges and tunnels; they are dominated by commanding peaks from which hostile artillery can be dislodged only by a slow and painful advance over most difficult topography; and important passes must be wrested from the controL of the enemy under conditions which make defense easy and offense (hazardous. Terrain Stretching southward from the southern foothills of the Piedmont ^Ips is the alluvial plain of the Piedmont, formed of rock plain debris eroded from the mountains and spread out in great fans along the mountain base. The rivers which made this alluvial deposit flow southeastward down its slope to the Po or to the Adriatic, some with meandering courses while others were so overburdened with debris that they developed a braided pattern about countless island sandbars. Near the sea the plain is very low and marshy, and characterized by extensive lagoons back of narrow barrier beaches. This lagoon and marsh belt varies in width from ten to thirty miles or more, and interposes a serious obstacle to the movement of troops ; but between the marshes and the mountains only the transverse rivers oppose the ready advance of armies over THE ITALIAN THEATER OP WAR 123 the level surface of the plain. These rivers have played an important role in Italian military history in the past, and may conceivahly do so again in the near future. Almost all of the Austro-Italian frontier lies in the difficult Position country of the Alps. Only at the extreme east does the inter- °* ^'j? national boundary descend to the plain and run across its nearly level surface for twenty or thirty miles to the head of the Adriatic Sea. Even here an important advance from Italian to Austrian territory is not so easy as might appear from the definition of the frontier; for just east of the political boundary the Piedmont plain ends abruptly against the base of the mountains which bend southvs'ard from the Alps to border the Dalmatian coast. No appreciable advance into Austria is possible except over difficult mountainous country. That portion of the international boundary lying in the Strategic Alps is located in a position which, from the standpoint of tagea^of"' military strategy, is highly unfavorable to Italy. It lies Italy's close to the southern edge of the mountains, near the Pied- mont plain. Austria has the advantage of possessing most of the rough country as a bulwark against Italian aggression, but may herself sweep down upon the Italian plain with a minimum of difficulty. The boundary follows minor crests, dominated by higher ridges to the north from which the Austrians may often look down upon the Italian frontier as from an aeroplane. In part it runs transverse to the grain of the country, repeatedly descending to a low level in order to cross the bottoms of main glacial troughs and minor val- leys which trend roughly from north to south. Through these valley depressions Austria may move downstream across the boundary into Italy with comparative ease. Italian troops must always work against gravity, moving up valley and up mountain slope in advancing into Austria. The plains portion of the frontier is easily crossed in 124 TOPOGEAPHY AND STRATEGY IN THE WAR Terrain of the Isonzo region Natural defenses against an Austrian advance The Tagl- iamento River either direction. But just east of the boundary line, and parallel to its bendings, is the Isonzo Eiver, its upper portion occupying a glacial trough in the mountains, its lower part flowing with a somewhat braided pattern through a marshy flood-plain on the sloping surface of the Piedmont, to end on a delta projecting into the head of the Adriatic. This natural line of defense is not only the first obstacle to a further invasion of Austria, but also serves as a special pro- tection for the important railway line just to the east which connects the interior of Austria with its princiiDal seaport, Trieste. East of the railway rise the mountains already mentioned, terminating the Piedmont plain in this direction, and offering an almost impregnable bulwark against an Italian offensive. Should the Italian offensive fail, and Austrian troops in- vade Italy, the advance would probably come from the Trentino on the north or from Gorizia on the east. From the base of the mountains to the margin of the lagoon belt there is no serious natural obstacle to troops advancing from the north. Armies moving from the east, on the other hand, would have to cross one after another of the parallel rivers which flow down the slope of the plain. These successive de- fensive lines would be utilized by the Italians to retard an Austrian advance, and should cause invading armies serious embarrassment. Some of the rivers, particularly the Taglia- mento and the Piave, have an extraordinarily braided pat- tern, the interlacing network of channels being crossed by good roads only at infrequent intervals. On the banks of both these streams important military actions have occurred in the past, and in this respect history will repeat itself if during this war the Teutonic allies prove able to prosecute an extended invasion of Italy from the east. In this con- nection it is interesting to note that when Italy entered the war not a few of her citizens feared a modern irruption THE ITALIAN THEATER OP WAR 125 of the Huns from beyond the Isonzo, and had resigned them- selves to the possibility of an invasion as far west as the Tagliamento. It veas realized that this historic barrier, with its multiple channels and shifting sandbars, flanked on the north by Alpine ridges and on the south by coastal marshes, would undoubtedly put a check on the advance of the foe, and perhaps mark the western limit of the invasion. Italy's grievances against Austria consisted not alone in Italy's the fact that Austria dominated and threatened the southern fgainst''^^ country from a frontier topographically well-nigh impreg- Austria nable, but from the further fact that much of the territory north and east of the boundary was Italian in speech and sentiment. Both to regain her unredeemed territory and to remove the constant menace of hostile attacks from her hereditary enemy, Italy requires a boundary nearer the crest of the mountains which will give her some control over the main gateways into her dominions. Whatever the outcome of the war, some rectification Proposed of the present frontier to the advantage of Italy may g^ang^'^^ confidently be expected. Such rectification was, indeed, the subject of negotiations between Austria and Italy prior to the latter country's entry into the war in 1915. Austria at that time proposed to cede to Italy a portion of the Trentino or " Siid-Tirol " as it is illogically called by the Germans. The territory which Austria was willing to abandon to prevent Italy from joining the Allies coincided roughly with the extension of Italian language north of the Italian frontier. Italian demands were based, however, as we have just seen, upon strategic necessities as well as linguistic considerations. They therefore outlined a frontier farther north, nearer to the Adriatic watershed. In a general way this line ran eastward from near the Swiss boundary, through Klausen to the vicinity of the Tre Croci pass (see Map p. 121), thus giving Italy control of the exits from the two 126 TOPOGRAPHY AND STRATEGY IN THE WAR upper branches of the great Etseh valley leading southward into Italy. Of these the easternmost is of greatest strategic importance, since through it comes the main railway from Germany over the Brenner pass, and the strategic railway which runs parallel to the frontier for nearly one hundred miles on its way eastward to Vienna. The fact that the proposed boundary was to cross this eastern branch valley at Klausen, a " close " or narrow pass in the valley, emphasizes Italy's desire to secure a location for the dividing line which should be topographically adapted to effective defense. The old Bishopric boundary from 1106 a.d. to the Reformation followed this line. If there is any flaw in this proposed rectification of the Italian Trentino frontier it is due to the fact that the Bozen district, thereby incorporated in the southern kingdom, is Teutonic in speech and feeling, al- though economically it is Italian. Austria's The line upon which Austria was willing to agree strikes south in such manner as to avoid cession to Italy of any ter- ritory of German speech. In doing this, however, it leaves some of the Italian-speaking northeastern districts of the Noce valley in Austrian territory. All the mountain out- lets which converge into the Etsch valley are also retained by Austria. From the Italian standpoint this is inadmis- sible, as it would leave the southern country unduly exposed to unwarranted aggression from the north. To the im- partial observer it would seem that the Italian claim offers the more equitable division of those strategical advantages which each nation considers essential to national security. It would leave to Austria the watershed, a position admirably suited for defense; and would at the same time award to Italy the control of the outlet passes. Each country would thus find itself secure from sudden aggression on the part of the other. The Austrian offer, on the contrary, altogether disregards Italy's strategical necessities. Typical terrain of the Italian front in the Dolomite Alps of the Trentino. THE ITALIAN THEATER OP WAR 127 With this general survey of the Italian frontier and its Two problems we may turn our attention to the campaigns for Jjo^t^" Italia Irredenta and examine them to find what features of the topography have most profoundly affected the fighting in this theater of war. It will immediately appear that there are two principal fields of operations, the Trentino front and the Isonzo front. Let us consider these in the order mentioned. CHAPTER XII CAMPAIGNS FOE ITALIA lEEEDENTA Italian objectives The Adige or EtBch valley The Trentino Front There were many reasons why the Trentino should be the object of one of the two campaigns first undertaken by Italy. As a " lost province " largely inhabited by Italians its occu- pation was calculated to inspire enthusiasm in the army of liberation and in the breasts of the people who must support the army. As a salient of hostile territory thrust far into Italy the Trentino constituted a danger which could be re- moved only through its conquest. Of all the glacial troughs leading southward through the Alps, the valley of the Adige (Etsch) which bisects the Trentino from north to south is one of the most remarkable, and is economically and strate- gically the most important. Its flat floor, from less than one mile to more than two miles broad, is traversed by two ex- cellent carriage roads and by a railroad of the highest pos- sible strategic value. By way of the low Brenner pass (4,495 feet) both carriage roads and railway afforded the chief means of communication between Italy and Germany, while the railway was the only line by which Austria could send reinforcements, ammunition, and supplies to the Tren- tino. The fortified tovim of Trent, and the outlying fortress of Eovereto, twelve miles farther south, both lie in this same trough. It was the richest valley, the chief commercial route, and the easiest natural line of invasion open to the Italians, besides containing the towns whose capture would have the greatest military significance. (See Map, p. 121.) 128 Central News. A trencli in the rocks and snows of the Alps. Note the snow-laden barbed wire entanglements in front of the trench. CAMPAIGNS FOR ITALIA IRREDENTA 129 Fortunately for Italy there are other routes of invasion converging on Trent, so that the difficulties of advancing along the narrow Adige valley were to some extent offset by Routes of the opportunity of cooperation with supporting columns in neighboring valleys. The southern apex of the Trentino peninsula may be entered through the glacial trough just west of the Adige, occupied by Lake Garda and the Sarca River, or farther west by the parallel trough occupied by Lake Idro and the Chiese River, and known as the Giudi- Giudicaria caria valley. Italian armies advanced northward through '^'^"^3' all three of these glacial troughs, and fierce fighting took place on Monte Baldo, the high ridge which separates the Adige and the Garda-Sarca troughs and dominates military operations in both. From the two sides of the Trentino peninsula flank attacks against the Adige valley and its important railway were pos- sible by way of other glacial troughs and mountain passes. On the eastern side the great trough of the Brenta River, known as the Val Sugana, may be followed westward to where Val it heads on a low col at the very gates of Trent. A railroad "^ through the valley adds to its strategic importance, and a large Italian army moved on Trent by this route. Other armies attacked the Monte Croce pass (5,3Y4 feet), Tre The passes Croci pass (5,932 feet), Ampezzo pass (5,066 feet), Fugazze pass over the southern shoulder of Monte Pasubio, the passes of the upper Assa and Astico valleys, and other openings by which carriage roads cross the mountain ridges from Italy into the eastern side of the Trentino. On the western side an important advance was begun through Tonale pass (6,181 feet). From all sides of the Trentino salient the fighting was promptly carried into Austrian territory. It may be doubted whether the Italian supreme command Italian expected the immediate conquest of the Trentino. The diffi- campaign culties in the way of an offensive in this wild mountainous 130 TOPOGRAPHY AND STRATEGY IN THE WAR region are colossal, and it may well be that Cadorna elected to hold the Austrians at bay here with inferior numbers, while he concentrated his energies in the campaign for Trieste. To remove the menace of an Austrian invasion and to contain their armies within the Trentino for a period of . months or possibly years, demanded that every gateway into Italy should be seized and sealed by the Italian armies. This alone involved a prodigious effort by Cadorna's soldiers, who were compelled to attack the problem from the disadvan- tageous lower ground south of the frontier. No army could be safe on the Isonzo front so long as its lines of communica- tion, which crossed the Piedmont plain just south of the Trentino, were threatened by any possibility of an advance from that district; hence the gateways must be held in abso- lute security. This could best be done by pushing through them into Austrian territory and fortifying their northern approaches. If the Austrians were not in sufficient strength to prevent a continued advance and the early conquest of the province, so much the better. Blocking Whatever his immediate objective Cadorna acted with vigor, the passes r^-j^^ armies striking north through the three parallel trenches of the Adige (Etsch), Garda and Giudicaria glacial troughs captured the fortified town of Kovereto and advanced almost within sight of the capital city of Trent, thus removing the threat of an irruption of the Huns through the southern exits from the Trentino. On the west the Stelvio, Tonale, and other minor passes were securely blocked. On the east the army in the Sugana trough left the frontier some miles behind it, while the high passes farther north were seized and firmly held. By quick action and heroic endeavor the soldiers of the south had neutralized to some extent the ad- vantages initially held by their enemy of the north. Let us pause for a moment to picture to ourselves what this mountain warfare of the Trentino is like. Nowhere CAMPAIGNS FOR ITALIA IRREDENTA 131 else in the great war have soldiers of the Allied armies en- countered such appalling obstacles as confronted the famous Alpini of Italy. Nowhere else is warfare so amazing, so Mountain spectacular. The wildest regions of the Vosges, the most hf thT^ difficult mazes of the Balkan ranges, the most formidable Trentine barriers of the Carpathians, are tame as compared with the towering precipices and icy peaks of the Trentine Alps. Here no continuous line of trenches is possible; solid rock defies the spade and the only soil is often that carried up from below in sandbags to be used as breastworks. Else- where piles of stones give uncertain protection, and during a bombardment more men are sometimes killed by flying rock splinters than by shrapnel. Occasionally trenches are cut in snow or in ice. The troops are scattered in groups occupying strategic points and observation stations on high peaks, rather than disposed along a nearly continuous front. Even where trenches exist they are not always constantly occupied as on the Western front. The opposing lines are often neces- sarily far apart, and observers on the peaks can warn the defenders of an enemy attack in ample time for them to assemble in whatever section of trench may be threatened. Artillery fire in the "Vosges may start landslides creeping Avalanches down the slopes, loosened by the concussion of the big gun artillery discharges ; but in the Alps avalanches of snow and ice have fire resulted, which, descending the precipices, have overwhelmed men and guns on the slopes below. In the high altitudes frost action shatters the solid rock into blocks and slabs, producing the felsenmeer so well known to the mountain climber. Both Austrian and Italian troops have utilized this natural ammunition, piling the rock masses high on tem- porary platforms projecting over the cliffs, and releasing the whole at the proper moment to fall with crushing force upon the enemy below. In the solid limestone of some of the peaks galleries and observation posts have been hollowed 132 TOPOGRAPHY AND STRATEGY IN THE WAR Subterra- nean gal- leries and chambers Teleferic railways Military mountain- eering Military transport in the Alpine terrain out, from which the movements of the enemy may be observed without fear of the heaviest bombardment. One Austrian stronghold captured by the Italians comprised an elaborate system of gun chambers, ammunition storage vaults, oflScers' rooms, and connecting tunnels, all comfortably heated and Well lighted by electricity, and all hollowed out of the solid rock. In point of numbers the troops engaged along a front of this type may be surprisingly small. We read of an impor- tant peak being captured by twenty-five men, or of an attack on a high pass by one company of infantry supported by a few field guns. Large forces cannot move in such a difficult terrain ; and if they could, it would not be possible adequately to supply them. Ordinary means of transportation must be supplanted by aerial trams or " teleferic railways," wire rope cables stretched from peak to precipice and equipped with baskets sliding on a grooved pulley. In these small containers food supplies, field guns, and ammunition are raised to apparently inaccessible heights, and the severely wounded are brought down two at a time. Heavy artillery must be dragged up the steep slopes and hoisted over vertical precipices by cables of special strength running over pulleys and operated by man-power; for batteries of big guns at elevations of nine and ten thousand feet, thundering above the clouds, form part of the incredible warfare on the Italian front. The uniform of the soldiers includes a white cap and coat to render them invisible on snowfield or glacier, while skis, ice-axes, and alpenstocks form an essential part of their equipment. Battles are fought in this land of the clouds in which the attacking forces must cross the icy sur- face of a glacier in order to reach the enemy lines. Even on the slopes below the highest peaks the problem of supply is a difficult one. Sure-footed mules are much in use, but they alone cannot solve the problem. What were CAMPAIGNS FOR ITALIA IREEDENTA 133 steep mountain trails a few years ago are perforce used as roads in the pressure of war. Auto-trucks with transverse cogs projecting from broad iron tires creep slowly up the zig-zag paths. The army engineers have triumphed over the obstacles of Nature to the extent of transforming many of the trails into a network of mountain roads, with stone or steel bridges over the torrents. These will remain when the war is past, and will aid Italy in developing the lands she may conquer. Today they minimize but do not obviate the difficulties of transportation in the Trentine Alps. In addition to munitions, food, and other supplies, water in Water enormous quantities has to be brought up in casks to the high plateaus and ridges, and distributed to the men scat- tered far over the rugged terrain. Every offensive must be preceded by an accumulation of water to go forward with the troops, as well as by accumulations of shell to make the advance possible. Nowhere in the Alps is warfare sim- plified, although the lower ridges permit operations on a somewhat larger scale than would be possible in the higher regions of perpetual winter. An effective picture of Italian mountain warfare is given Conquer- by an observer * on the Trentino front, who shows an un- Alpine usual appreciation of the topographic difficulties encountered ^ by the soldiers of Cadorna's armies. " Monte Cristallo, which dominates the Ampezzo basin, on the Italian side, shows an almost vertical face nearly 5,000 feet high. The Alpini attacked it armed with ropes, climbing-irons, and rock-drills. For a week they worked at the escalade, ignored by the Austrians, who never expected that any attempt could be made to reach them up this apparently insurmountable cliff. But the pioneers drove rings and iron pegs into the wall of rock, and from day to day mounted higher, while their comrades followed up the ladder they had made. Grad- * Sidney Low in " Italy in the War." 134 TOPOGRAPHY AND STRATEGY IN THE WAR Prepara- tions for Austrian offensive in Tren- tino Location of Aus- trian main attack ually they collected in the gullies and clefts under the sum- mit ; and then one night they stole out on the crest and rushed the Austrian garrison, too surprised and dismayed to offer more than a feeble resistance to these shouting groups of fierce foes, who seemed to have descended upon them out of the clouds." When the first Italian advance into the Trentino had been checked a few miles within the border, the invading armies settled down to the slow and painful conquest of the formidable terrain, peak by peak and ridge by ridge. Mean- while the Isonzo campaign was well under way, and was giving the Austrian high command not a little uneasiness. To check operations in this eastern field and to punish the Italians for their alliance with the Entente, a vigorous offen- sive was undertaken by the Austrian armies. Heavy rein- forcements of men and enormous quantities of supplies and munitions were brought down the Adige valley, and con- centrated about Trent. The process of accumulation was necessarily slow, for through the single narrow trough of the Adige all the men and supplies, big guns and munitions had to pass to their destination. Means also had to be devised to distribute water to the great armies during their advance. When the number of men exceeded a third of a million, and the massed batteries numbered a couple of thousand guns of all calibers, the blow was struck, about the middle of May, 1916. Apparently the Italians had not believed that the Aus- trians would be able to accumulate such masses of men and stores in the Trentino, and were taken by surprise. Their advance posts were crushed by sheer weight of numbers, and fell back rapidly. The main attack came in the mountainous triangle south of the Val Sugana and east of the Adige val- ley. In the center of this district the Austrians recaptured the mountain passes and pushed southeastward into Italian CAMPAIGNS FOR ITALIA IRREDENTA 135 territory. For a week, for two weeks, for three weeks, the furious battle went on, the Austrian invaders creeping pain- fully forward, capturing a peak here and a ridge there by Advance virtue of enormous sacrifices of men and prodigal use of T'^'^,, heavy artillery. The higher peaks were left behind and the plateau Italians forced out over the Asiago plateau, a broad upland closer to the border of the mountains. Not far beyond lay the low level Piedmont, and the railways which were vital arteries, giving life to the Italian armies on the Isonzo front. A few miles more, and the Austrians could debouch on the plain, cut these arteries, take the Isonzo armies in the rear, and possibly overwhelm them with irretrievable disaster. But the Austrian machine was beginning to lag. Its Bifficult advance over an impossible terrain was destroying its momen- ,jefeats tum. Frontal assaults against mountain peaks and ridges Austrian stubbornly defended by the agile Alpini took a terrible toll in killed and wounded; lines of supply were lengthening, and food, water, and munitions had to be brought farther and farther over wild mountain trails; at the end of a month the accumulated surplus of men and munitions had been consumed in driving the Italian army back through a comparatively few miles of the rugged Alps; there was no reserve force to push them on to the plain beyond. 'Now was Cadorna's opportunity. With a hastily gathered new army he fell upon the exhausted Austrians toward the middle of June and slowly beat them back over the rough country, through which they had just come. The Austrian invasion was turned into an Austrian retreat. One hundred thousand Austrian much needed men and countless stores of munitions of war had been wasted in a vain effort to break through the moun- tain barrier to the fair plain of northern Italy. With his lines of communication secure, Cadorna was free to turn his attention once more to the Isonzo campaign. 136 TOPOGRAPHY AND STRATEGY IN THE WAR Terrain of the Isonzo region Natural fortifica- tions guarding Gorizia and Trieste The Isonzo Front Standing on the Italian border southeast of Udine, one has before him a broad panorama of plain and mountain. In front of him stretches the smooth Piedmont sloping gently toward the sea. Down this slope from north to south the Isonzo Eiver takes its sluggish way, choked Avith numberless sandbars and wandering through marshy flats. Low dikes hold the waters in check lest they flow too far over the adjacent lowland. Beyond the river rises a steep mountain wall, even-crested toward the south, but merging into the complex mass of Alpine peaks farther north. Di- rectly opposite, the towers of the Austrian city of Gorz, — Gorizia since its capture by the Italians, — are visible in a wide recess in the mountain wall formed by the broad Wip- pach valley. South of the city the even crest of the wall is the top of the far-famed Carso plateau ; while on the north the Bainsizza plateau stands guard on the other side of the city. West of the river a long spur of the Julian Alps runs south to protect the city gates. Such are the natural fortifications blocking the way to Trieste. The route to that port along the sea follows the southern base of the Carso plateau, while the other route, via Gorizia, ascends the Wippach valley. Imagine yourself west of the Isonzo, attempting the task of the Italian army. Gorizia, an important field base, is one of your first objec- tives. There it lies just beyond the river, nestling securely in its mountain fastness. You approach the treacherous Isonzo and find the bridges partially destroyed. The guns of Monte Sabotino and Podgora on the spur of the Julian Alps fire upon you from the north ; the guns of Monte Santo, San Gabriele, and San Daniele, high points on the rim of the Bainsizza plateau, threaten you from the northeast; the guns of Monte San Michele on the crest of the Carso belch CAMPAIGNS FOR ITALIA IRREDENTA Figure 15. The laonzo front, showing the Carso and Bainsizza plateaus and the mountain peaks which formed the principal Austrian strongholds. 138 TOPOGRAPHY AND STRATEGY IN THE WAR The impossible task Crossing the Isonzo barrier Defensive use of floods steel upon you from the south. Boats and pontoon bridges are destroyed in this hurricane of cross-fire, and you begin to realize that you cannot cross the river until you have captured the protecting mountains, and cannot reach the mountains until you have crossed the river. You are ready to believe the memorandum said to have been issued to the Austrian soldiers at the beginning of the struggle on the Isonzo front : " We have to retain possession of a terrain fortified by Mature. In front of us a great watercourse; behind us a ridge from which we can shoot as from a ten- story building." To achieve the seemingly impossible task of crossing the Isonzo under heavy fire, storming the heights of the Carso and Bainsizza plateaus and the Alpine peaks, and capturing the mountain-walled fastness of Gorizia was the first prob- lem which confronted the Italian armies. The story of the successful solution of that problem will live long in the annals of Italian warfare. The wonder is not that the task took so long, but rather that it was ever accomplished. War was declared by Italy on the evening of May 23, 1915. Cadorna struck without a moment's delay, and by morning his armies had swept across the boundary on the level plain, and were capturing Austrian towns in swift succession as they rapidly advanced toward the Isonzo barrier. How the river was crossed under murderous fire will only be known when the whole story is told after the war. We hear of pontoon bridges destroyed and renewed with feverish activity, of boats and rafts braving the hail of steel, and of soldiers plunging into the stream in the race for victory. We know that a foothold was speedily gained on the eastern bank at some places, while weeks went by before other portions were crossed. During one of the crossings at the very base of the Carso the river was in flood, and by opening the dikes the Austrians ■^ -J SlSHr i i 1 P ^^^^H^iJ J 1 1 IP'li"^!^ 1 ^.■^^■^/■SSi^: m ^»'' ^ ^^Wi'fei ..■■>, 9 :,i: ■ •, . ■■> pi T' (V ' 'M^^l CAMPAIGNS FOR ITALIA IRREDENTA 139 deluged the surrounding country to depths as great as six feet. To reach their objective the Italians were forced to push through the flooded districts, fully exposed to a gall- ing fire from the long scarp of the plateau, to repair the dikes and permit the floods to subside, to cross the river and fight their way through muddy flats to the base of the cliffs, and then painfully to work their way up the steep rocky slopes to the fortified upland above. Every step of this difiicult journey was made under fire from high peaks and plateau scarps which encompassed the attackers on three sides, every step was exposed to the enemy's view as he looked down on the plain from his high observation stations, and every step meant the destruction or conquest of enemy forti- fications long believed to be impregnable. Can one marvel Italians that the Italian advance was slow from the moment the ^t the Isonzo barrier was reached? From Monte Sabotino and ™ountain barrier Podgora on the north to Monfalcone on the south the first wave of the Italian advance dashed against the rocky bar- rier along the river, and was checked. A year was to pass before the Latin tide would rise high enough to overflow the crest of the Teuton dam. Gorizia could not be taken nor the routes to Trieste opened Steep up until a part at least of the formidable Carso plateau had ^.jjg carso been wrested from Austrian control. It is not easy ade- quately to conceive the stupendous difficulties of the Carso terrain. The plateau is a flat-topped mountain from four to six miles broad, which runs parallel to the coast and at no place far from it. Its sides are precipitous, and as it rises from three or four hundred to more than a thousand feet above the surrounding lowlands, it constitutes a gigantic rock-walled castle whose guns control with ease the city of Gorizia, the crossings of the Isonzo, and the two pathways to Trieste. Its lower slopes are partly wooded, but higher up the steep rimming scarp is bare and rocky. Merely to 140 TOPOGRAPHY AND STRATEGY IN THE WAR Eocky desert of the Carso upland Monte San Michele The Vallone scale the walls is therefore a military feat of no small magnitude. The upland surface is a hot, thirsty, wind-swept desert. The rock is limestone, and its ready solution permits the development of underground channels by which all moisture quickly escapes to great depths. Scanty vegetation relieves but slightly the barren aspect of this desolate land without rivers, brooks, or springs. It is the typical dry, rocky desert of the karst type, for which its name, Carso, is the Italian equivalent. Like other karst lands the surface is excessively irregular, pitted with sink-holes without number and under- mined by subterranean caverns. The sink-holes, or " doli- nen," are funnel-shaped depressions from fifty to several hundred feet in diameter and fifty or a hundred feet in depth. They end in passageways connecting with the vast labyrinth of underground caves and galleries. Over the sur- face rise many low hills and an occasional mass of more im- posing dimensions, like the Monte San Michele. Nature thus provided ready to hand innumerable concealed sites for heavy artillery, machine gun emplacements, observation stations, and secure underground retreats for vast numbers of troops. And what Nature offered the Austrians had ac- cepted and improved by long years of elaborate fortification. Trenches had been cut in the solid rock, elaborate systems of galleries and tunnels had been excavated, gun emplacements had been prepared in pits quarried for the purpose, and the whole system connected by covered communication trenches and supplied by water pumped up to the thirsty surface and distributed by pipe lines. The western end of the plateau is cut off from the main Carso by a deep trench, plainly visible on the map (page 137), called the Vallone. Thus even should the Italians cross the Isonzo barrier, scale the rocky walls of the plateau and conquer Monte San Michele and the rest of the western CAMPAIGNS FOR ITALIA IRREDENTA 141 upland (sometimes called the Boberdo plateau), their further Doberdo progress would be disputed at the deep, wide trench just P^'^^^^.u • described. South of the main plateau are outlying hills like the Hermada, which must also be conquered before the main The road to Trieste can be opened. These rise as high as the Carso itself, and cannot therefore be dominated from the main tableland. Each- such natural fort must be taken by storm as the armies make their way slowly along the coast. Such was the formidable terrain which the Italian armies Italian set about to conquer. Once over the lower course of the o'f^the^ Isonzo, with Monfalcone and Gradisca securely in their difficult hands, they attacked the walls of the plateau all around its western extremity. Day after day, week after week, they burrowed up the barren slopes, driving deep trenches in the solid rock farther and farther toward the crest, boring great tunnels hundreds of yards in length which should ultimately open within a few yards of the Austrian main defenses. Spade and intrenching tool were useless here, and the miner's pick, drill, sledge-hammer, and dynamite were called into play. Sandbags, brought up from the plain below, were built into breastworks which afforded the workers some protection from the deadly flying splinters of rock dislodged by the enemy's constant artillery bombardment. Farther north the same methodical preparations were Trenching being carried out against enemy strongholds on the peaks neiing of the Alpine spur west of the Isonzo. Eock trenches were being driven toward the works crowning the hills north of Podgora, while the almost inaccessible positions on Monte Sabotino were secretly being reached by a tunnel more than a mile in length. Week after week, month after month, the laborious task was pursued, early assaults having convinced Cadorna that the bravery of his troops would not alone make possible the conquest of a terrain where all the topographic advantages favored the enemy. What surface conditions 142 TOPOGRAPHY AND STRATEGY IN THE WAR Second Italian offensive Scaling the Carso Gorge of the upper Isonzo Third Italian offensive made impossible he must achieve by an advance under- ground. At length, in the first week of August, 1916, more than a year after the first Italian soldiers had crossed the Isonzo, the second Italian blow at the Austrian barrier was struck. A terrific bombardment from the greatly strengthened Italian artillery preceded the attack. Then the troops con- centrated in the tunnels and deep rock trenches burst from the ground within a few yards of the astonished Austrians. The crest of the Carso from Monf alcone around to and includ- ing Monte San Michele on the north was carried by storm. In the Alpine spur the Podgora positions were seized and the supposedly impregnable Monte Sabotino passed into Italian hands. Gorizia was still held by the enemy, and the road to Trieste was far from open. But the advance had begun which should slowly creep forward till Gorizia was no longer tenable by Austrian troops, and Italian artillery pounding on the Hermada should demand an entrance into the port of Trieste. North of Gorizia the Isonzo flows in a deep glacial trough, bordered on the east by the Bainsizza plateau and on the west by more irregular spurs and peaks of the southeastern Alps. This trench long held the Italian armies at bay, even when its northern course had successfully been crossed and Tolmino brought under Italian fire from captured positions on Monte Nero. At intervals Cadorna's soldiers crossed the river on pontoons under heavy fire, and dug themselves in on the lower levels of the Bainsizza plateau. Slowly they pushed their trenches up the steep slopes toward the crest and went " over the top " to capture Monte Cucco on the westernmost edge of the upland. A year after Monte Sabotino fell we find Monte Santo and Monte San Gabriele, just across the river, passing into Italian control, while Monte San Daniele, a neighboring peak on the edge of the CAMPAIGNS FOR ITALIA IRREDENTA 143 Bainsizza plateau, was to hold out still longer. The wild upland surfaces of Bainsizza and the Carso were slowly being conquered by the relentless advance of Cadorna's men, and the Austrians were losing their grip on the strategically important Chiapovano valley separating the Bainsizza and Ternovano plateaus and connecting the Austrian front with the railway in the rear. Incredible deeds had been accom- plished by Italian arms, but more than two years of almost superhuman effort had not served to open the rocky gate- way to Trieste. CHAPTER XIII THE BALKAN THEATER OF WAR The Balkan Barrier Balkan Neae the head of the Adriatic there rise several small in 1915 streams whose waters flow almost due eastward through the Save and Danube Rivers, to empty into the Black Sea. South of this west-to-east river trench, and separated by it from the open plains of Hungary and Rumania, lies the rudely triangular mass of complex mountainous country known as the Balkan Peninsula (Fig. 16). The bulk of this difficult terrain long stood as an effective barrier between the Central Empires and their Turkish ally. The northwestern corner of the triangle, comprising Bosnia and Herzegovina, was largely under Austrian control, while in the eastern corner the Turks were effectively resisting all attempts of the Allied armies and navies to dislodge them. But the rest of the territory was either openly hostile to the Teutonic powers, or was maintaining a wavering neutrality which constantly embarrassed communication with the Turks and threatened to become an active menace at any moment. It was to resolve this intolerable situation and to impress the world by a decisive military achievement that the German General Staff planned the Balkan campaign of 1915. The Morava-Maritza Trench Two stra- Through the mass of the Balkan Mountains rivers have cut trenches^'^ two great trenches which constitute the only important lines of communication in the region. One of these passageways 144 Figure 16. Map showing barriers Abbreviations. ( 1 ) In northern Serbia, etc. : Lo, for Losnitza ; Ma, for Malyen Ric ISe, for Semendria; U, for Uzhitze; Va, for Valyevo; Vi, for Vishegrad; Z, for Zaietch L, for Jjeakovatz; Ve, for Veles; Vr, for Vranye. (3) Elsewhere: Du, for Durazzo (on ' S£KW!*^i /ft *f]^-''«.. ^Adrianople'-'^j^y^ ;Dedeag^B "'WVil yP^''> ' ';;o''i.'''*'i# "^'1''-!;;;^''* ■i-;"^''*';.., f" l?Si '40 Tenches of the Balkan Peninsula. li, for Mitrovitza (on the Save) ; 0, for Orsova; Ob, for Obrenovatz; S, for Shabatz; 2 ) Along the Morava-Vardar trench ; D, for Demir Kapu gorge ; Ku, for Kumanovo ; Iriatio) ; I, for Ipek (421/2° N. and 20° E.) ; K, for Katchanik (42l^° N. and 21° B.). THE BALKAN THEATER OF WAR 145 or " corridors " runs southeastward from Belgrade on the Danube to Constantinople on the Bosporus and consists in large part of the valleys of the Morava and Maritza Rivers. The other connects Belgrade with the harbor of Saloniki on the Aegean Sea and is formed by the Morava and Vadar valleys. From Belgrade as far as JSTish the Morava valley is common to both routes. Although possession of the Morava-Vardar trench incidentally became essential to the Teutonic powers for military and political reasons discussed below, it was primarily for control of the Morava-Maritza depression that the campaign was undertaken. The full significance of the Morava-Maritza trench can The be appreciated only in case we recall the important role it J^°rftza' has always played in the history of the Nearer East. From trench in I historv ' all parts of Europe highways of travel converge southeast- ward toward the points where Occident and Orient touch hands at the Bosporus. Whether coming from the plains of the Po over the Pear Tree pass, from western and central Europe along the upper Danube, or from farther north through the Moravian and other gaps to the Vienna gateway, travelers find the mass of the Balkans blocking the path to Constantinople and the East; just as in other days the hosts which invaded Europe from the lands of Asia Minor found in this same barrier an impediment to progress toward the northwest. Under these conditions it was inevitable that a continuous river trench cutting clear through the barrier from the plains of Hungary to the shores of the Bosporus should become a topographic feature of commanding his- torical importance. Long before the time of the Romans the Morava-Maritza Roman valley had become a highway for peoples migrating east or ™'^'^*^^'^^ west through the mountainous Balkan lands. In a later day one of the principal Roman military roads led froni Belgrade through the trench to Constantinople, The great 146 TOPOGRAPHY AND STRATEGY IN THE WAR Route of the Crusaders Berlin to Bagdad railway Terrain of the Morava- Maritza trench Morava valley Slavonic flood which issued from the plains of northeastern Europe through the Moravian and Vienna gateways entered the Morava valley and, in the seventh century of our era, was flowing through the trench to surge about the walls of Adrianople. A few centuries more, and the mountain sides were echoing the shouts of the Crusaders who toiled along the same pathway to fight for the Holy Sepulcher. Back through the same defile came those hordes of conquering Turks who pushed the limits of their misrule to the very gates of Vienna. In our day a double line of steel rails has succeeded trail and military road, and the smoke of the Orient Express hangs low in the very valley where, centuries ago, dust clouds were raised by the passing of Roman legions, Crusading knights, or Turkish infantry. Here is the vital link in the great Berlin-to-Bagdad railway route, the chan- nel through which German ambition hopes to reach the Far East, and the path by which the Teutonic powers must send men and munitions to the hard-pressed Turks and bring back food to their own hungry people. Let us examine for a moment the physical characteristics of the stream-carved trench which has figured so prominently in the past history of southeastern Europe and which again has focused upon it the eyes of the civilized world. The mouth of the Morava valley is widely open to the plains of Hungary, where the Morava River unites with the Danube some miles east of Belgrade. Southward up the river the valley narrows gradually, and the hills on either side rise to mountainous proportions ; but as far up as Nish it is mature, with a flat and sometimes marshy flood-plain over which the river flows in a complicated meandering course, with occa- sional oxbow lakes and braided channels. Only at two points, where the river has probably cut through ridges of exceptionally resistant rock, does the valley narrow to a more youthful form and force the better roads to make long THE BALKAN THEATER OF WAR 147 detours over the hills. There is usually ample room for a main road on each side of the river, while the railway crosses from one bank to the other in order to connect with the larger towns located on the valley floor. The river is navigable half-way up to Nish, and throughout the entire distance the flood-plain soils yield rich harvests of maize and wheat. From Nish the route leads southeastward up a branch Niahava stream called the Mshava, to a low divide within Bulgarian ■*'*"^y territory. The valley of the Nishava is more youthful than that of the Morava and is so narrow in places that the wagon road twice abandons it for a course across the moun- tains. The railway is able to follow it throughout, however, and in one place the valley widens to a broad basin on the floor of which lies the important town of Pirot. Here fortresses crowned the adjacent hills to guard against a Bul- gar invasion of Serbia along this comparatively easy path. After crossing the divide at Dragoman pass, about 2,500 Sofia feet above sea-level, both road and railway descend to the ^^'" broad, fertile floor of the Sofia basin. Fortunately this trends northwest-southeast and is thus in line with the gen- eral course of the Morava-Maritza trench, although it drains to the northeast through a narrow outlet gorge into the Danube. At the southeastern end of the basin the low Vakarel pass, but little higher than the Dragoman, is crossed, and road and railway easily reach the much larger basin drained by the Maritza Eiver and its tributaries. The Maritza takes a direct course toward Constantinople Maritza for more than 150 miles, then turns abruptly south- ^^^^^y ward to the Mediterranean Sea. At this sudden bend in the river stands the fortified city of Adrianople. Ex- cept for a short distance below the city, the Maritza no longer serves as part of the great pathway to Constantinople, but becomes a segment in the natural moat, consisting of the 148 TOPOGRAPHY AND STRATEGY IN THE WAR Natural moat protecting Constanti- nople Strategic value of the Morava- Vardar trench Topo- graphic key to Balkan history Tundja and lower Maritza valleys, which in the past has repeatedly provided Constantinople with an admirable first- line of defense against aggression from the west. Above Adrianople the river is too frequently obstructed with sand- bars to be of much use for navigation, but its broad basin carries the road and railway which follow the southern bank of the stream. South of Adrianople the small Ergene River flows to the Maritza from the east, and its valley offers a very gentle grade which the railway ascends till within a few miles of Constantinople. The Morava-Vardar Trench Second in importance to the Morava-Maritza corridor is the deep trench which cuts through the Balkans from north to south, connecting Belgrade with Saloniki. The Morava- Vardar depression does not lead to the land bridge uniting Europe with Asia Minor, but it does serve as a most im- portant outlet channel from the plains of Hungary to the Mediterranean Sea, and is one of the shortest routes from central Europe to the Suez Canal. Erom southern Germany and the eastern Alps, the foothills of the Carpathians and the Alps of Transylvania, and from all of the great Hun- garian basin, the valley routes lead straight to Belgrade, whence the Morava-Vardar valley cleaves a way through the mountains to the open waters beyond. It is not without reason that the Morava-Vardar trench has been called the key to the history of the Balkan peninsula. Through it ebbed and flowed the tides of repeated invasions from the dawn of history. Under Roman dominion most of it was occupied by an important military road. Through it the Ostrogoths entered northern Greece in the fifth century, a.d., while names still found on the map of Greece bear witness to the great Slav flood which, two centuries later, flowed through the trench and overwhelmed the Greek peninsula. The story Central Newa. Italian artillerymen dragging a giant howitzer up a steep mountain trail in the Alps. Italian Official Photo. One phase of mountain warfare. An engine driving rock drills used in excavating a tunnel under Mount Tofana. By means of this tunnel the Italians undermined and blew up an Austrian fortress on the moun- tain top. THE BALKAN THEATER OF WAR 149 of the Serb race is largely the story of a struggle for control of this vital artery of communication. Austria's ambition to seize for her own uses a channel to the sea which should Austrian not open on the inclosed Adriatic has been the mainspring of her reactionary policy in Balkan affairs. Bulgaria, real- izing that the nation which dominates the Morava-Vardar Bulgarian depression must ultimately dominate the polities of the pen- ambitions insula, precipitated the second Balkan war in order to make good by force of arms her claim to a section of the trench; and the same incentive played an important part in deter- mining Bulgaria's alliance with the Teutonic powers in the present conflict. Most of the friction between Greece and the Entente Allies had its inception in the fact that Greece controlled one section of a channel all of which was essen- tial to the existence of Serbia. The Belgrade-Saloniki rail- way was the main artery of commerce which carried through the trench the life-blood of a nation. The physical characteristics of the Morava valley as far Terrain south as Nish have already been discussed in connection with Morava- the Morava-Maritza trench. From Nish southward to Vardar Leskovatz, road and railway traverse one of the open inter- montane basins which frequently occur in the midst of the Balkan ridges; but farther south the stream flows from a youthful gorge which continues up the river for ten or twenty miles before the valley again broadens out to a somewhat more mature form. Just north of Kumanovo lies the divide between the Morava and Vardar drainage, a low, inconspicu- ous water-parting some 1,500 feet above sea-level, located in the bottom of the continuous, through-going trench, and plac- ing no serious difficulties in the way of railroad construction. South of Kumanovo the valley broadens into a triangular lowland, near the three corners of which stand Kumanovo, tjskiib, and Veles. The main Vardar Eiver enters the low- land from the west, flowing out again at the south through 150 TOPOGRAPHY AND STRATEGY IN THE WAR Demir Kapu gorge a narrow, winding valley which carries the railway, but no good wagon road. At Demir Kapu the valley narrows to an almost impassable gorge for a distance of several miles but soon broadens again to a flat-floored valley in which the river follows a braided and occasionally meandering chan- nel to the sea. The lower course of the Vardar lies in a very broad, marshy plain terminating in the delta southwest of Saloniki. The special strategic importance of the triangular lowland near Uskiib and the Demir Kapu gorge will be emphasized later. While the Morava River is navigable for small boats from the mouth half-way up to Nish, the upper Vardar is too full of rapids and its lower course too full of sandbars to make river traffic practicable. The strategic value of the Morava- Vardar trench, like that of the Morava-Maritza, lies in the fact that, notwithstanding it occasionally narrows to gorge- like proportions, it gives an unbroken channel-way clear through a rugged mountain barrier. Morava- Maritza trench and German diplomacy Peaceable Conquest of the Maritza Valley The immediate object of the Balkan campaign of 1915 was to secure for Germany complete control of the Morava- Maritza trench and the Orient railway which runs through it from Belgrade to Constantinople. Roughly speaking, one- third of the trench was in Turkish territory, and therefore already subject to German supervision; one-third was in Bulgaria ; and the remaining third in Serbia. German diplomacy set itself the task of inducing Bulgaria to become an ally of the Central Powers, in order that the middle third of the Morava-Maritza trench might pass under German control without a contest and in order, further, that Bul- garian troops might bear the brunt of the fighting necessary to capture the remaining third from Serbian hands. THE BALKAN THEATER OF WAR 151 This was truly an ambitious plan, but certain considera- Geographic tions having a geographic basis made it possible for Ger- ^f Bulgaria many to crown the program with success, and that with slight cost and incalculable profit to herself. The close of the sec- ond Balkan war found Bulgaria not only bitter from the disastrous defeat with which her treachery to her allies had been punished, but suffering serious geographical dis- advantages from the illogical boundaries forced upon her. Rumania's appropriation of the Dobrudja brought hostile territory close to Bulgaria's chief seaport of Varna and also menaced the safety of the railway connecting with the port, since this line lies parallel to the new boundary and close to the frontier. The natural outlet for all central Bulgaria Bulgaria's is to the Mediterranean by way of the lower Maritza River; i"^^ but the reconquest of Adrianople by the Turks led to a divi- sion of territory which forced Bulgarian goods enroute down- stream to the Bulgarian port of Dedeagatch to cross through a small section of Turkey. The only other natural channel to the Mediterranean from Bulgarian lands was down the Struma valley to the port of Kavala ; but Greece in her turn had insisted on a boundary which should leave the lower course of the river and the port in her hands, thus compelling Bulgarian commerce by this route to pass through Greek territory. Finally, Serbia obtained possession of that section of the Morava-Vardar trench which Bulgaria had coveted, leaving to the latter no part of the key to future power in the Balkans. The opening of the present war thus found Bulgaria with a serious geographical grievance against every one of her neighbors. AVith coast lines bordering on two seas, every bit of her commerce, save only that with Russia, was forced to pass through hostile lands. Here was a fertile field for German diplomatic effort, A bargain and Bulgaria lent a willing ear to plans which promised "* valleys immediate redress of past wrongs. Turkey was induced to 152 TOPOGRAPHY AND STRATEGY IN THE WAR return to Bulgaria the strip of land west of the lower Maritza, thereby insuring to her a railway connection to her Mediterranean port lying wholly within her own boun- daries. As a further reward for direct action against Serbia, Bulgaria should receive the coveted section of the Morava- Vardar trench, the conquest of which would be rendered easy by Teutonic cooperation from the north. It was a bargain in valleys. In return for free use of the upper Maritza valley, and assistance in effecting the conquest of the Morava valley, Bulgaria was to receive a part of the lower Maritza valley and a section of the Vardar valley. German diplomacy won, the geographic bargain was made, and from that mo- ment there remained only the problem of forcibly seizing the Morava-Vardar trench. Teutonic plan of campaign Natural Defenses of the Morava-Yardar Trench While conquest of the Morava valley and its continuation up the tributary Nishava was alone necessary to complete Teutonic possession of the Belgrade-Constantinople railway route, two considerations made a comprehensive campaign against the entire Morava-Vardar trench essential. In the first place, as we have just seen, the "Vardar valley had to be secured for political reasons, since its possession by Bul- garia constituted an essential part of the Teuton-Bulgar bargain. But military reasons also required its capture. It constituted the one effective line of communication leading to the Serbian armies defending the northern frontier. To cut it was to deprive those armies of reinforcements, muni- tions, and other supplies coming from the south. Further- more, possession of the Morava-Maritza trench would never be secure so long as Serbia and her allies held the Vardar depression, for at any moment they might launch a bolt along this natural groove which would sever the Orient rail- THE BALKAN THEATER OF WAR 153 way at Nish and thus undo all that had heen accomplished through the new alliance with Bulgaria. For the Teuton- Bulgar forces the capture of the combined Morava and Var- dar valleys was a single military problem. Let us examine the physiographic features which serve as natural defenses of this important trench. The Morava valley is widely open to the north and is Natural there bounded on both sides by comparatively low hills. An „„ the enemy securing a foothold in the rolling country to the east "ortl» or west could enter from either of these directions as well as from the north, just as the Orient railway, coming from Belgrade enters the valley from the west, twenty-five miles above its mouth. Hence an effective barrier against attack from the north must cover more than the actual breadth of the northern entrance to the valley. Such a barrier is pro- vided by the natural moat of the Save and Danube Rivers which protects the entire northern frontier of Serbia; and by the hills south of the moat which, as one progresses south- ward, rise into a wild, mountainous highland. The Save is a large river swinging in great meanders Valley of across a broad, marshy flood-plain. The extensive swamp- lands on either side of the river are difficult to traverse at any time, while the flood waters which spread over the low- land in spring and autumn often make the barrier quite impassable except at Mitrovitza (not to be confused with the Mitrovitza near the Kosovo Polye referred to farther on). South of Mitrovitza and west of Shabatz the marshy penin- sula between the Drina and the Save is called the Matchva Marshes and is famous for its inhospitable character. In volume Matchva the Save is of sufficient size to constitute an obstacle against invasion, but for purposes of navigation it suffers from its overlong meandering course and from frequent shifting of channels and sandbars. At no point is the stream fordable, and at Belgrade alone is it crossed by a bridge. 154 TOPOGEAPHY AND STRATEGY IN THE WAR Valley of the Danube Iron Gate Save- Danube barrier in history Natural defenses on the east The Danube is a river of imposing volume, in places from one to several miles wide. Its value as a defense against invasion is very great, notvpithstanding that the numerous islands -which mark its braided course from Bel- grade east to the Iron Gate gorge offer some advantages for a crossing. It is unfordable and unbridged. East of the braided section the river exchanges its open valley for a narrow, winding gorge which cuts through a mountainous upland and reaches its most imposing aspect at the Iron Gate near Orsova. The walls of the gorge, sometimes forest- clad, sometimes bare rock, are exceedingly steep; while the mighty volume of water constricted within its narrower chan- nel gives a river which is both swift and deep. To cross such a barrier in the face of enemy fire would severely test the abilities of the best-trained soldiery. It is not strange that so impressive a natural obstacle as the Save-Danube valley should have served for centuries as a bulwark against invasion of the Balkan peninsula from the north, nor that it should long have been the physical barrier separating the dominions of the Sultan from Austrian lands. In combination with the difficult hill country to the south, the great natural moat furnished the Serbians with an admirable defensive screen, in attempting to pierce which the Teutonic armies suffered more than one costly defeat. Throughout its entire length the Morava-Vardar trench is protected on the east by a complex of mountain ridges rep- resenting the western ends of the Balkan and Bhodope masses and the southwestern extremity of the Transylvanian Alps. All of these ranges appear to have reached a mature stage of dissection in which the maximum degree of ruggedness is attained. A maze of steep-sided ridges and peaks rises from one to several thousand feet above the bottoms of narrow valleys, while at the north the mountain barrier is reinforced by the gorge of the lower Timok River and a short section THE BALKAN THEATER OP WAR 155 of the Danube valley. Much of this difficult country is for- ested, and no part of it could be crossed with ease by a hostile army. There are, nevertheless, certain pathways through the Passes 1 . , . , . ■, -, ^ ■, ^ r ■ through eastern barrier which might be forced by a toe possessing the superior numbers. Chief among these is that segment of the t^^^^^j™ great Morava-Maritza trench carved by the Nishava Eiver, which unfortunately rises within Bulgarian territory, and flows directly through the barrier into the Morava-Vardar trench at the critically important junction near Nish. To stop this gap the fortifications of Pirot just inside the Ser- bian border were constructed. Zaietchar, another fortified town farther north, guards the common entrance to the Tsrna and upper Timok valleys, through which hostile forces might ascend to passes whence the drop into the Morava valley is readily effected. The Vlasina, Kriva, and Bregal- nitza Rivers, rising at or near the Serbo-Bulgarian boun- dary on the crest of the main range and flowing west- ward to the Morava and the Vardar, give access to the trench at Leskovatz basin, at Kumanovo, and in the Veles-Krivolak region. Finally, the broadly open Strumitza valley, mainly in Bulgarian territory, but heading close to the lower Vardar, affords access to several passes from which it is but a few hours' march to the Vardar trench either above or below the Demir Kapu gorge. It appears, therefore, that despite the protection afforded Vulnera- by difficult mountainous country east of the Morava-Vardar tion^nhe line, the trench was open to attack at a number of critical Morava- . Vardar points, provided the invading forces were sufficiently large trench to overwhelm resistance and drive their columns through the narrow valleys. This danger was the more acute be- cause along much of the eastern frontier Bulgarian territory reaches the crest of the mountain barrier and in some places even beyond the crest to the western or Serbian slope. It 156 TOPOGRAPHY AND STRATEGY IN THE WAR Political conditions on the west Natural defenses on the west should be noted, furthermore, that the hostile territory flanks the Morava-Vardar trench throughout practically its entire length, usually lying not more than fifty miles distant, while near Vranye and just north of the Greek border westward protrusions of the Bulgarian frontier reduce the distance to a dozen miles or less. The largest and most vital artery carrying the life-blood of Serbia lay dangerously near the surface, and a single stab of the Bulgarian knife might prove' fatal. West of the Morava-Vardar trench the threat of danger was less imrninent, and the natural protective screen more effective. Although Bosnia and Herzegovina were in Aus- trian hands, the people were more or less hostile to their new rulers and favorably disposed toward the Serbs. Monte- negro was Serbia's ally^ while uncertain Albania was not an important factor in any event. Across the Adriatic lay Italy, another ally of Serbia. Only at the north, then, was there danger of an attack upon the Morava-Vardar line from- the west; while farther south succor from friends, rather than attacks from enemies, was to be expected from the direc- tion of the Adriatic. The broad belt of mountains lying between the Morava- Vardar depression and the Adriatic shore is one of the most imposing topographic barriers in Europe. From the earliest times it has stood as an almost impassable wall cutting off the people of central Serbia from all effective intercourse with the inhabitants of the Italian peninsula. In the Middle Ages, Ragusa and other Slavonic cities on the Adriatic coast, although part of a Serbian province and the' home of a flourishing school of Serbian literature, found communica- tion with the interior so difficult and with Italy so easy that they came under Venetian instead of Serbian control. The same mountain wall which so long prevented extension of Serbian power westward to the sea, likewise served for THE BALKAN THEATER OF WAR 157 centuries as an effective barrier against the eastward migra- tion of western European civilization into the dominion of the Turks. To the present day no railroad has crossed the barrier to unite the great valley of central Serbia with the sea. Included in the mountainous belt are ranges high enough The moun- to carry snow caps until the month' of August, and the name terrain in " Albania " is believed by some to have its origin in the history snowy appearance of that wild region. It is said that the " Accursed ' mountains " of northern Albania and eastern Montenegro include some of the least explored lands of all Europe. Just as the mountains of Wales and the Highlands of Scotland preserve languages and customs which have been driven from the open country of England, so the fastnesses of the Albanian hills have kept alive a difficult language that' is older than classical Greek and customs which render the rude inhabitants of the country a picturesque subject for study. The conquering arm of the Turk reduced the Bul- garian 'inhabitants of open plains to complete subjection within a comparatively short time; but a century and 'a quarter was required to secure a less firm hold upon the mountainous lands of Serbia, while the inaccessible wilds of Albania' and Montenegro were never completely subjected to Turkish power. Montenegro was the last Serbian strong- hold to yield to Turkish supremacy and the first to regain complete independence. The physical characteristics of a belt of country so diffi- Parallel cult to traverse deserve a word of further description. In vaUeys^'' the north the mountains consist of much eroded earth folds of the Appalachian type, trending northwest-southeast par- allel to the northern Adriatic coast and rising from 5,000 to 8,000 feet above sea-level in the higher ranges. Between the hard rock ridges streams have excavated parallel valleys on the weaker beds, but these valleys are of little real service 158 TOPOGRAPHY AND STRATEGY IN THE WAR Karst to- pography Intermont basins to man since they lie at right angles to the natural course of his movements between coast and interior. Farther south the rock structure is more complex, and the mountain ridges produced by erosion accordingly of more complicated pattern. Among the rocks involved in the mountain building, lime- stone is a conspicuous element, and its soluble nature has im- posed a peculiarly forbidding aspect on the topography. Most of the rainfall passes underground through sink-holes and smaller solution cavities and then finds its way through subterranean channels to a few principal rivers, lakes, or the sea. As a consequence much of the mountain country is dry and barren, springs are far apart, and the open water courses difficult of access because deeply intrenched in rock-walled gorges. The " gaunt, naked rocks of the cruel karst coun- try " are not only themselves of little value to mankind but they render inaccessible and therefore comparatively useless many excellent harbors on the east coast of the Adriatic. Because the limestones are purer and more abundant along the coastal border we find that the karst topography is there best developed. Farther inland the maze of hills is occasionally broken by an intermontane basin, the center of whose broad floor may be covered by marsh land, while throughout its remaining portion the fertile soils derived from impure limestone and other rocks yield good returns to the cultivator. Among the largest of the basins are those in which Monastir and Ipek are located ; the Tetovo basin, west of IJskiib, where an important branch of the Vardar Eiver takes its rise ; and the famous Kosovo Polye, or Plain of the Blackbirds, southeast of Mitrovitza, where in its last great effort against the advancing Turk the Serbian army suffered defeat in 1389. It is largely to these areas that one must credit such measure of prosperity as is vouchsafed the dwellers of this western mountain barrier; but absence of Copyright by Underwood & Underwood. Serbian troops crossing the Kolubara River barrier on the ruins of a bridge which was repeatedly destroyed and repaired during the fighting along this stream. Central News. A barren basin or " polye " in the Serbian mountains. The bad road has caused the cart to upset, with resulting injury to the driver. THE BALKAN THEATER OF WAR 159 connecting lowlands makes the basins of small service in expediting travel across the region. It is true that certain rivers cut through the mountain Transverse ranges to reach the sea ; but not one of these has carved a ^°'^^* valley suitable to serve as a highway between the coast and the central Morava-Vardar trench. For the most part the cross valleys are narrow and deep and bounded by the steep, rocky walls characteristic of young gorges cut in limestone. Falls and rapids are frequent, and the headwaters usually end in a maze of ridges some distance west of the central depression. The valley of the Narenta carries a narrow- Narenta gauge railway through the mountains of Bosnia and Herze- 8°'^8e govina to a pass, across which Sarayevo and the valley of the Save are accessible; but the only branch line running east to the Serbian border terminates in the vicinity of Vishegrad, while the nearest railway terminus of the Serbian system is more than twenty miles Across the mountains at Uzhitze at the head of the Western Morava valley. Through the gorge of the middle Narenta the course of the railway is difficult, and the crossing of the pass is made possible only by using a rack-and-pinion arrangement, which indicates the unsatisfactory character of the route for commercial pur- poses. The next river of importance to the south is the Drin, Gorge of which reaches the sea near Scutari ; but it flows in a gorge so ^ ^^^ wild and deep that the poor trails of the district often leave it for a course across the barren hills. When a column of Serbian troops successfully negotiated this defile during the first Balkan war, the feat was hailed as a great military accomplishment. The Shkumbi valley offers an entrance Shkumbi from Durazzo to the rail-end at Monastir, but traffic by this ^^^^^y route must cross three mountain passes. A famous Roman road, the Via Egnatia, followed this valley; and the only other two important roads to cross the barrier in Roman times had their locations determined by the Narenta and 160 TOPOGRAPHY AND STRATEGY IN THE WAR Kolubara valley Western Morava Ibar valley Katchanik pass the Drin, although in each case the stream gorge was aban- doned in places for a more feasible course over the uplands. Of these former roads little, remains today except rugged mule paths. From the standpoint of military geography the broad mountain belt west of the Morava- Vardar trench is practically impassable. There are within this western mountain belt three de- pressions which have relatively little value as part of cross- routes to the sea, but which we must keep in mind if we are fully to understand certain aspects of the campaign against Serbia. First among these is the open Kolubara valley, at the head of which stands the town of Valyevo. A small railway of some military value traverses the valley and con- nects the town with the Save Kiver. Directly south across the Malyen ridge, the Western Morava valley heads near Uzhitze and rilns east to join the main trench. The West- ern Morava Kiver is a mature stream meandering on a flat flood-plain of considerable breadth and is bordered by a narrow-gauge railway connecting Uzhitze with the Orient Express line. Finally, the Kosovo Polye, already mentioned, forms part of a subsidiary trench parallel to the main Morava depression. Northwestward the basin is replaced by the long, narrow, winding gorge of the Ibar Kiver, which unites with the Western Morava, but which is not followed throughout its length by so much as a good wagon road. To the south- east the basin is drained by the Lepenatz River, which flows through a narrow outlet gorge at Katchanik, the so-called Katchanik pass, to unite with the Vardar at Uskiib. An important railway leaves the Nish-Saloniki line at tjskiib and runs through the Katchanik gorge and Kosovo Polye to Mitrovitza on the Ibar. Our examination of the surface -features of the region under discussion has developed the fact that the Morava- Vardar trench is well protected against invasion, whether THE BALKAN THEATER OF WAR 161 from the north, the east, or the west ; but it appears that the most effective protective barrier is on the west, where it is least required and where, indeed, it might shut off much needed succor from Italy in a time of peril. Let us now trace the history of the campaign against Serbia in the light of our knowledge of the topography. CHAPTEE XIV CAMPAIGNS AGAINST SERBIA First blow of the world war First at- tempts to cross the Save- Danube barrier Early Campaigns for the Morava-Vardar Trench Austria's first attacks against the northern barrier formed by the Save-Danube moat and the rising hills to the south were ostensibly made primarily for the purpose of punishing Serbia, while the idea of securing a portion of the Morava- Vardar trench was kept in the background. The first blow in the world war was struck in the last days of July, 1914, when Austria launched a strong offensive along the entire Save-Danube line. The Serbians destroyed the great bridge over the Save at Belgrade in order to make the barrier more secure and assailed with vigor every enemy column which endeavored to cross the river by boats or pon- toon bridges. Eor nearly two weeks the Austrians made repeated attempts at seven different points to reach the south bank and at the same time attacked the line of the Drina near Losnitza and Vishegrad. At Belgrade a crossing in the shelter of the ruined bridge was only temporarily successful. Farther east, at Semendria, an island served as the base for crossing on a pontoon bridge where the channel narrowed to 200 yards; but the invaders were first held in check, then thrown back in defeat. All attempts to cross at Obrenovatz, southwest of Belgrade, failed. Far to the west Austrian troops succeeded in forcing a passage at Mitrovitza and for some days held their ground in the marshes on the south side of the stream; while the Drina was crossed at Vishegrad. Even here the success seems to have been partial and tem- m . , CAMPAIGNS AGAINST SERBIA 163 porary, for Vishegrad was retaken by the Serbs August 7th, and on the 10th the Serbian government reported the ex- pulsion of the last Austrian from Serb territory. The first attempt to force the northern barrier had ended in failure. A second attempt was made immediately. After a furious Second bombardment of the Save-Danube line superior Austrian * ^^^ forces crossed the Save at Shabatz and the Drina at Losnitza, while columns attempting to cross at Belgrade were defeated. In the gorge of the Iron Gate at Orsova, where the swift current and steep walls made the attempt peculiarly hazard- ous, it is said that three Austrian regiments were destroyed while trying to cross by a pontoon bridge. Renewed at- tempts to cross at Belgrade and Semendria were frustrated. Belgrade, stands on the point of a peninsula projecting into Natural Hungarian territory and is subject to attack from three sides. BelgraTe It was the capital of Serbia, and its capture was urgently desired for political as well as strategic reasons. That this important outpost at the very door of the enemy's country, attacked by superior numbers and bombarded by superior artillery, should have resisted capture for four months, is a striking proof of the strategic importance of such barriers as the Save and Danube Rivers. Meanwhile, on August 20th the Austrian armies which had entered northwestern Serbia were overwhelmed with defeat after a four-day battle in the foothills east of Losnitza and in the marshes of the Matchva near Shabatz and were driven back across the Drina with heavy losses. Fleeing remnants of the invading force overcrowded the few bridges spanning the unfordable stream and large numbers perished by drowning. A second attack against the natural defenses of northern Serbia had proven futile. About the end of the first week in N'ovember, 1914, Austro- Third Hungarian armies more than 300,000 strong launched a third ^ ^^^ attempt to force the northern barrier. The open valley of 164 TOPOGRAPHY AND STRATEGY IN THE WAR Serbian victory of Malyen ridge the lower Drina and the marshy Save River were crossed by superior forces with the aid of heavy artillery. Advancing up the Kolubara valley and the low foothills on either side as far as Valyevo the Austrian center prepared to attack the Serbian position on Malyen ridge, while the left wing occupied Belgrade, and the right wing captured Uzhitze. Apparently the plan of campaign was for the Austrian cen- ter and right wing to converge upon the head of the Western . Morava valley and then follow down that depression into the main Morava- Vardar trench, thus outflanking the forces de- fending its northern end. Meanwhile the small Serbian army was giving a good account of itself, defending river and marsh and hill slope with such effect that not until the first of December did the Austrian forces reach the Uzhitze- Valyevo-Belgrade line. A month of desperate fighting with heavy losses had elapsed before the invaders were ready to attack the main Serbian defensive position on Malyen ridge just south of Valyevo. Then came the stroke which startled the world. Assuming the offensive and sweeping down the slopes of the Malyen, the Serbian veterans overwhelmed the whole Austrian army with disaster. Valyevo was recaptured, Belgrade and Uzhitze cleared of the enemy, and all northwestern Serbia swept clean, except the marshy peninsula between Shabatz and the Drina, where Austrian troops maintained a foothold with the aid of topography especially favorable for defense. The upper Drina was crossed by the victorious Serbs, and Sarayevo seriously threatened. A badly beaten Austrian army retired to Austrian soil, to have its commander officially disgraced for the crime of failure. Whether because of diffi- culty in bringing adequate supplies across the marshy Save and over the foothills to the Austrian front, or because the Austrian forces had been unduly weakened in their month's campaign against the Serb defenses, or because the difficulties CAMPAIGNS AGAINST SERBIA 165 of the Malyen position were underestimated arid troops werfe detached to serve elsewhere, a third attempt to force this natural protective barriers of northern Serbia had ended in a costly defeat for the Teutons. It was now evident that Austria, with many of her troops Austria's engaged on other fronts, could not assemble forces com- to force the petent to dislodge the Serbians from their favorable de- difficult <■• •■»i • -If TT terrain ferisive position. At the same time the need of controlling the Morava-Vardar trench was increasing. The Central Powers were besieged by the Allies, and an outlet to neutral lands and to the sea was a pressing necessity. The Turks needed munitions and the Central Po'wers needed food. A successful campaign was also required to wipe out the dis- grace of past defeats at Serbian hands and to impress waver- ing neutrals with Teutonic military prowess. Hence was initiated the diplomatic campaign already described, which German culminated in the peaceable conquest of the Maritza valley garian"a'id and the accession of Bulgarian troops to the ranks of the Central Powers. Conditions were now ripe for a combined Teuton-Bulgar campaign designed to conquer the entire Morava-Vardar trench. The Conquest of Serbia Early October, 1915, found some 200,000 Germans and Serbian Austrians massed on the Save-Danube line, while a larger defense number of Bulgars were concentrating in the mountains along the eastern border. The main Serbian army stood behind the northern defensive line to meet the Austro-Germari at- tack, smaller forces alone being detailed for operations on the east. A Bulgarian offensive was to be met by the Greek army acting in concert with an Anglo-French Expeditionary Force. At the last moment the whole scheme of Serbian de- fense was shattered by King Constantine, who repudiated 166 TOPOGEAPHY AND STRATEGY IN THE WAR Crossing the river barrier Slow Teuton advance in hill country Greece's treaty with Serbia and refused the promised sup- port of his army. The entire length of the Morava-Vardar trench was thus thrown open to flank attacks from the east while the main Serb armies were trying to protect the north- ern entrance. On October 6th the Austro-German assault was launched. Heavy artillery fire, which the Serbians could not match, protected the columns attempting to force a passage across the river barrier. Nevertheless, the crossing was a costly undertaking; many of the invaders were driven back to the north bank or caught on the south side and annihilated, be- fore large forces after two or three days' hard fighting securely established themselves on the southern bank. It is interesting to note that the principal crossings were effected above Belgrade, below Belgrade, at Semendria, Bam, and Gradishte, — all five of them points close to the northern entrance of the Morava valley, all of them except the last located at the ends of Hungarian railways capable of bring- ing supplies directly to the points of crossing, and all of them near sandbar islands in the river which were utilized to good advantage in several and possibly in all cases. There also was heavy cannonading at Orsova, the only other rail- head on the Danube frontier; but no crossing of the diSicult gorge near the Iron Gate seems to have been made until later, possibly after threat of envelopment caused withdrawal of the main body of defenders from the northeast corner of Serbia. When the crossing was effected it was with the aid of an island in the river below the town. After the Danube barrier had been forced, the southward progress of the Teutonic armies was reinarkably slow. Tor six weeks the average rate of advance was about one mile a day. Despite their enormous superiority in big guns, it cost the Austro-Germans much tim'e and the loss of many men to drive the Serbs from successive defensive positions CAMPAIGNS AGAINST SERBIA 167 in the hills. More than two weeks elapsed before the Danube was freed from the Serbian menace and so rendered available for boat transport of munitions to Bulgaria and Turkey. Austrian forces crossing the Drina near Vishegrad, the only rail-end on the northwestern frontier, found themselves un- able to dislodge the Serbs from their mountain fastnesses, and after ten days' fighting had made no progress toward the head of the Western Morava valley. The Bulgarian Attack Meanwhile Bulgarian armies poured through gaps in the Flank eastern mountain barrier and descended tributary valleys ^^^^^^ °" •' •' Morava- to the Morava-Vardar trench. One column descended the Vardar Vlasnia valley to the Leskovatz basin, another reached Kuma- nova and Uskiib by the Kriva depression, while a third de- scended the Bregalnitza to Veles. Vranye, Kumanovo, IJskiib, and Veles, defended by inadequate Serbian forces, were captured within less than two weeks, and the vital artery of Serbia cut in four places. Few could doubt but that these wounds would prove fatal. Farther north one Bulgarian army was attacking the Conquest fortifications of Pirot in order to open a way down the °^ *^® . . Morava- Nishava valley to ISTish, while other forces had captured Maritza Zaietchar and were trying to push up the Tsrna and the upper Timok to reach the Morava trench above and below Jfish. Progress in this field was much slower than farther south, however, and the Serbs maintained themselves in the moun- tainous northeast corner of their country until the fall of Pirot and Nish developed the danger that Bulgarians push- ing north down the Morava and Austro-Germans advancing up the valley to meet them might close the neck of the salient northeast of the trench and capture the forces fighting there. Under pressure of this threat the Serbs withdrew to the 168 TOPOGRAPHY AND STRATEGY IN THE WAR Disastrous results- of Bulgarian occupation of Morava- Vardar trench Serbian retreat to the higher mountains southwest; and about iNovember 13, or more than a month after the campaign opened, the entire Morava-Maritza trench was in the hands of the Central Powers, and the reconstruc- tion of the Orient railway could be prosecuted. The Morava- Vardar trench as far south as Veles was also in their con- trol, and there remained only the problem of rendering the tenure of both trenches secure by pushing the Serbian and Franco-British forces west to the Adriatic and south to the Aegean. The disastrous results of the Bulgarian occupation of the Morava-Vardar trench now began to be more manifest. Munitions and other supplies for the Serbian armies in the north were becoming exhausted, and the one artery along which they could freely flow had been severed. The quan- tities which could reach the Serbian front over rough moun- tain trails were utterly inadequate. Keinforcements were sadly needed ; but the one railway leading north from the Anglo-French base at Saloniki followed the Morava-Vardar trench, and so was in the hands of the enemy, while the rough mule paths over the western mountain barrier could bring neither troops nor supplies from Italy. Had the broad belt of mountain and karst intervened between the Morava-Vardar trench and the Bulgarian frontier, and had the more open valleys of the east but led westward to the Adriatic, the history of the Balkan campaign would have been very different. The Battle for Katchanih Pass It was supposed that when the Austro-German forces reached the higher mountainous region bordering the Western Morava valley and it became difficult if not impossible to bring up their heavy guns, the rate of advance would become even slower than before. The fact that the advance was actually accelerated has been interpreted to mean that the CAMPAIGNS AGAINST SERBIA 169 failure of Serbian supplies weakened the defense more than the unfavorable local topography injured the plans of the offensive. The Teutons moved rapidly across the Western Morava, and the Serbian army took up a position running eastward along the mountain crests south of the valley, then southward along the ridge west of the Morava- Vardar trench, and southwestward across the Katchanik gorge. It will Katchanik ,. , ^^ , ._ . ? pass as a immediately appear that the Katchanik position was the strategic strategic key to this entire battle front. In the rear of the ^^ Serbian armies facing north and east, runs the straight subsidiary trench formed by the Lepenatz valley, Kosovo Polye, and the Ibar valley. The gateway to this trench is the narrow Katchanik gorge. A railway from Uskiib ruils through the gorge to Mitrovitza at the north end of the Kosovo Polye, thereby more than doubling the strategic value of the depression. If the Bulgarian forces already in possession of Uskiib should succeed in breaking through the Katchanik gorge into the plain of Kosovo, they could strike north arid east against the rear of the Serbian armies and convert re- treat irito disaster. Little wonder, then, that the " Katcha- nik pass " figured so prominently in the war despatches dur- ing this period ! But if Katchanik was the key to the Serbian position, Strategic Veles was the key to Katchanik. Should the Anglo-French the^Veks troops coming up the Vardar from Saloniki capture Veles basin and debouch into the triangular lowland to the north, they would take in the rear the Bulgarian army trying to break through the Katchanik position. It would not be necessary for the Anglo-French force to enter the Lepenatz valley ; the mere threat of inclosing the Bulgarians in the valley be- tween the Serbs up at Katchanik and their allies down at the valley mouth would be sufficient to bring the Bulgars out of the trap in order to fight on the lowland, where, if de- feated, they could retire northeastward into a region fully 170 TOPOGRAPHY AND STRATEGY IN THE WAR Serbs retire to Ipek and Monastir basins The winter retreat through the deso- late karst under their control. The threat would become imminent the moment Veles fell to the Allies. Such were the topographic relations responsible for the rather striking fact that an Anglo-French attack upon Veles relieved the pressure upon Serbian forces in the mountains far to the north. The strategic value of Veles was fully appreciated by the Bulgarian commanders, and heavy reinforcements were evi- dently poured into the Vardar trench at that point. All efforts of the Allied armies failed to achieve their purpose; Veles remained in Bulgarian hands and Bulgarian attacks on the poorly equipped Serbs defending Katchanik gorge pro- ceeded without serious interruption. When it became ap- parent that the Katchanik position could not long be held, the Serbian armies at the north and east fell back toward the Ipek basin, while those farther south retired on the Monastir basin. AH danger to the Teutonic occupation of the Morava- Vardar trench north of Veles was thus removed, and the remainder of the campaign consisted in squeezing the rem- nants of the shattered Serb forces and their Montenegrin allies westward through Albania and southward through Montenegro to the sea ; and in driving the Anglo-French army and the Serbs near Monastir back upon the Saloniki defenses. The first of these movements progressed with ex- ceeding slowness because of the difficult character of the country; and the terrors of the Serbian retreat over rugged mule paths and through wild mountain gorges in the cold and snow of winter can scarcely be imagined. But from the standpoint of strategic geography the second movement alone merits special consideration. Terrain of the Tsrna triangle The Armed Camp on the Tsrna When the French and English pushed up the Vardar valley toward Veles they seized as their base for a great armed camp the triangle of mountainous ground lying be- CAMPAIGNS AGAINST SERBIA 171 tween the Vardar Eiver and one of its tributaries known as the Tsrna, the latter a stream which must not be confused with the river of same name emptying into the Timok in northeastern Serbia. The position had certain topographic advantages which enabled it to be held for a long time in the face of superior forces ; but suffered from one serious dis- advantage which ultimately compelled its evacuation. Both the mountain ridges and the river trenches afforded admirable natural defenses. The gorge of the Tsrna is steep-sided and the stream unfordable. The only practicable bridge, a few miles above the river's mouth, was destroyed by the French after they had failed in an effort to move westward and join the Serbs, who were fighting at Babuna pass to prevent Babuna the Bulgars from getting into Monastir basin. For de- ^*^^ fensive purposes the larger Vardar Eiver, protecting the east side of the triangle, was strategically important, because it is both wide and unfordable and its valley is steep-sided, — in one place a veritable gorge. But it is in the Vardar valley that the chief disadvantages Vulnera- of the situation become apparent. All munitions and other J'^^^"^"*^ supplies, as well as all reinforcements for the armed camp, triangle had to come from Saloniki over the single-track railway running up the Vardar trench. The railway lies close to the river all the way and for several miles is actually on its eastern bank, or outside the triangle. Its position was thus dangerously vulnerable, and its vulnerability was peculiarly aggravated by the fact that in the Demir Kapu gorge, the Iron Demir Gate of the Vardar, the line is squeezed in between the ^^P^ base of high cliffs and the swiftly flowing river, crosses the river on a bridge at one point, and passes through a tunnel at another. If the Bulgarians, attacking the sides of the triangle, should destroy bridge, tunnel, or narrow road-bed in the gorge, the forces within the triangle would be caught in a trap. Hence it was that when the dispersal of the Serb 172 TOPOGEAPHY AND STRATEGY IN THE WAR Strength of the Vardar and Tsrna barriers The Allied positions French withdraw from the triangle armies to the northwest had so far progressed as to free addi- tional Austro-German and Bulgarian troops for action against the Allied armies at the south, the evacuation of the triangle was considered imperative. It has been estimated that at this time the forces of the Central Powers in the south probably outnumbered those of the Allies in the proportion of three to one, or even four to one. That the triangle should have been held so long in the face of greatly superior numbers bears eloquent testimony to the strength of the natural topographic barriers formed by the Tsrna and Vardar Kivers, as well as to the efficiency of the French who mainly were responsible for its defense. The British line now ran eastward from near the Demir Kapu gorge, along the ridge north of Lake Doiran and south of the Strumitza valley and, like the French triangle, was supplied by one single-track railway. The Serbian front in the Monastir basin ran from west to east just north of the town and connected with the French along the Tsrna Eiver side of the triangle. It also was dependent for supplies upon a single railway line. The French triangle was thus a prominent salient projecting far beyond the general Allied front; it possessed a vulnerable point, the Demir Kapu gorge, on the east side of the salient; and it was the center of a line the two wings of which were less effectively pro- tected by natural barriers and all of which was inadequately supplied with lines of communication. Early in December the withdrawal from this dangerous situation began. The French retired from the triangle and blocked the gorge against pursuit by blowing up the tunnel and bridge. The British were forced back toward the south- west by a series of furious Bulgarian assaults, and the Serbs were compelled to withdraw southward into Greek territory. The retirement was completed when the Allied armies fell back on the natural defenses of Saloniki. The great armed 03 g O CAMPAIGNS AGAINST SERBIA 173 camp based on this important port was securely protected by two lines of physical barriers, either of which could have been rendered practically impregnable. Inasmuch as this camp was to harbor a mighty army for years instead of weeks, and inasmuch as the failure of the Teutonic allies to attempt the task of driving the armies of Sarrail into the sea was probably dictated more by a knowledge of the formidable nature of the natural defenses than by any respect for the sham neutrality of the pro-German Constantine, we may profitably trace the two defensive lines and note what *^ '''^--rA-; >-i ":':-. mmda±»m^-'<^S*'JM\ ^;-s ff^"^ 1^^^ )l^ii Central News, Predeal pass, the main avenue of communication across the Transylvanian Alps from Bukharest to Kronstadt. CONQUEST OF RUMANIA 195 the Rumanians were unable to profit by their opportunity, and fell back to the first effective line of defense, the Olt Eiver, a fairly broad stream which issues from Transylvania through the Eed Tower pass and flows south across the Wal- lachian plain to the Danube. Unfortunately, the railroad which parallels this defensive barrier lies west of the river, and would thus give a lateral supply line to the Teuton pursuers, while the Eumanians would have no equivalent advantage. This alone was enough to render the line of the Olt of doubtful value. Aside from this consideration, it was questionable how long the Rumanian forces could hold the line under heavy Teuton fire when they themselves were unable to reply in kind. The issue was promptly settled, however, when Von Mackensen, profiting by the Rumanian shortage of munitions, effected a passage of the Danube under cover of superior artillery fire at Zimnica, thirty miles east of the lower Olt. This manoeuver completely out- Olt barrier flanked the whole line of the Olt, and the Rumanian army °" ^° ® fell back toward the east. The Wallachian plain is in large part an alluvial slope Rale of the underlain by sands and gravels deposited by streams issuing ^"g^^*' from the Transylvanian Alps, and is traversed by the ex- tensions of these rivers, roughly parallel to the Olt but swing- ing more toward the east in their lower courses. As the Rumanian armies withdrew from the line of the Olt they fought brief delaying actions along one and another of the parallel streams. Thus we hear of them deployed along the JSTiaslov River, and later find them fighting a vigorous action along parts of the Arges. This latter river was expected Arges by many to form the defensive screen for the capital, Buk- and the barest. It is, however, poorly adapted to such a purpose. ^f^^^_ A railroad parallels it on the side next the city, which is as harest it should be ; but the stream is not large, it lies too close to the city in its lower course, and its direction, strongly south- 196 TOPOGRAPHY AND STRATEGY IN THE WAR Rumani- ans retreat across the plain Mountain terrain as pivoting point Jalomitza River line Line of the Buzeu River east, facilitated the outflanking of the defenders by an enemy force advancing eastward after capturing Pitesti and cross- ing the stream near its headwaters. None of the parallel rivers is supplied with broad belts of marsh, which alone renders streams of moderate size really formidable militarj barriers. After abandoning Bukharest the Kumanian forces retired northeastward, constantly swinging around more and more to the north as required by the shape of the country between the parallel bends of the Transylvanian Alps on the north- west and the Danube on the southeast. To accomplish this the Rumanian line, now strengthened by a large force of Rus- sians, must pivot on its right wing, marking time there until the left wing, down near the Danube, could swing through a great arc and reach its appointed position. This was a difficult manoeuver, made possible by the fact that the coun- try increases in ruggedness toward the pivoting point. The Rumanian right wing held the Teutons at bay in the moun- tains, while the left retired swiftly across the smooth plain. During this part of the retreat we hear of a brief delaying action along the course of the Jalomitza River, and of a longer one at the Buzeu River. The Jalomitza is paralleled on its northern side by a railway which would afford the de- fenders a good lateral supply line, and the river with its more or less marshy flood-plain is a protective screen of some value. It would appear that this line was outflanked, however, when the Teutons crossed the small headwaters near Ploesti, cap- tured that town, and pushed on toward the town of Buzeu. One military critic based his discussions for some days on the thesis that the main defensive line to which the Rumanians were withdrawing was the line of the Buzeu River. Geo- graphic conditions are distinctly against this thesis. The river is of fair size, but its course would permit a dangerous outflanking move toward the east where the course of the CONQUEST OF RUMANIA 197 stream bends far to the north. The barrier is not suiSciently formidable to justify an attempt to hold its southwestern sector after other troops had reached its northeastern portion, thirty to forty miles in the rear of the first position. A former course of the river, leading more directly eastward to the Danube and now occupied by marshes and lakes, might make a better line so far as direction is concerned; but it is not a barrier of serious proportions. Another reason why the Rumanians could not stand on the Buzeu line is found in the position of the railway, which parallels the stream on the southern side, thus affording a lateral line of communi- cation for the enemy. With such an advantage the Teutons could quickly distribute men and artillery to any chosen point on the line and pierce it ; while the defenders, lacking lateral communications, could offer but feeble resistance. The same objection applies to the so-called Sereth-Trotus Sereth- line, selected by the same critic as the main defensive position jjj^° "^ after the Buzeu line had been passed. Both on the middle Sereth and the Trotus the railway is on the wrong side of the river. It would seem as though the railroads bad been placed with reference to a foe expected from the northeast rather than from the west. The Battle of the Sereth-Putna After a sharp contest on the Ramnic Eiver the Eusso- Retreat Rumanian forces took^their final stand behind the line of gereth- the lower Sereth and^Putna Rivers. Inasmuch as some Putna line critics were convinced that no attempt would be made to hold the Putna line, and since the Teutonic pursuit was in fact brought to a complete check along this line in spite of desperate fighting, it will be worth while to examine the physiographic characteristics of the Putna and Sereth val- leys with some care. 198 TOPOGRAPHY AND STRATEGY IN THE WAR Head- waters of the Putna Marshy valley of the lower Putna Vulnerable nature of terrain at Fundeni Marshes of the Sereth and Danube The Putna Eiver rises near the great bend of the Transyl- vanian Alps and flows in general southeastward across the plain to join the Sereth between the towns of Focsani and Galatz. Before leaving the mountains two main headwater branches of the stream flow toward each other along the pro- nounced lowland already described as extending parallel to the main crest, and unite to form a single river which has cut a transverse gorge through the flrst and most prominent of the secondary parallel ridges. In this region the Kuma- nians utilized the secondary ridge, which rises 1,500 feet above the adjacent valley, as their natural defense. After leaving the foothills, the Putna, still a stream of but moderate size, has a marshy flood-plain from one-third of a mile to more than a mile in breadth. In the vicinity of Focsani the marshes widen out to a breadth of several miles, but just below there begins a stretch of dry land which continues to Fundeni, and which would facilitate a crossing by hostile troops. Fortunately, it is just here that the Sereth flows parallel and close to the Putna for some dis- tance, reinforcing the latter by a really formidable obstacle. At Fundeni, however, there is neither marsh nor a double river barrier. Of all points on the Sereth-Putna line Fundeni appears to offer the best opportunity for an enemy crossing. The town lies on the north bank of the Sereth within a meander loop which projects southward. This would expose the town to a converging fire from three sides, and thus still further facilitate a crossing by hostile forces. It is true that there are some points favorable to the defense. The river at this point is nearly a quarter of a mile broad and too deep to ford. A number of old oxbow lakes on its southern side afford some additional protection. The great marshes of the lower Sereth begin close to the downstream side of the meander, rendering it difiicult for an enemy to develop the full force of a converging attack. But since the CONQUEST OF RUMANIA 199 mai*shes just referred to continue in a broad belt to tbe Danube at Galatz, and the Danube from Galatz to the Black Sea is an impassable barrier of distributary river channels on a marshy delta dotted with lakes both large and small, it must still appear that the Fundeni sector is from its physio- graphic character the point where enemy attacks should most confidently be expected. We have seen that the Sereth-Putna line is a defensive Railway barrier of some degree of formidableness. An examination caUmia"' of the railways in this region shows that the line is supplied ^^^^ °^ Ssreth- with lateral communications well adapted to deliver shells, Putna line supplies, and reinforcements to the defenders, wherever need should arise. The Sereth is paralleled by a railway from Galatz to the mouth of the Putna. The main central rail- way of Moldavia, over which Russian reinforcements must largely come, leads up to the center of the Putna defensive line, while a lateral branch connects this main railway with the one paralleling the lower Sereth. The extension of the Putna line along the secondary ridge and thence northwest past Oituz pass and Gyimes pass is paralleled by the Trotus valley railway. All these railways, it will be noted, are on the north of the defensive barrier, and so protected by it from hostile attack. This alone would be sufficient to explain why the Sereth-Putna line is superior to the Sereth-Trotus farther north, or the Buzeu line farther south. The Teutonic armies arrived before the Sereth-Putna line Attacks during the first week of January, 1917. They first tried sereth- to force the marshes of the Putna River north of Focsani, at ^^^^^ the end of the railway and highroad along which one of their main columns was advancing. At one time, under cover of a fog, some Teuton troops gained the northern bank of the river but were quickly driven back. A second attempt was Attempt made near Galatz, in the hope of turning the left flank of the e°gt"™j defensive line. After capturing Braila, a Teuton column of barrier 200 TOPOGRAPHY AND STRATEGY IN THE WAR Attack on the Fundeni sector Teutons fail to force the barrier Attempt to turn west end of barrier Terrain of Oituz pass struggled painfully along the railway embankment which crosses the marshes to Vadeni and the bridge over the lower Sereth. Many days of heavy fighting resulted in the cap- ture of Vadeni, but it proved impossible to manoeuver to ad- vantage in this region of marshes. The crossing of the river could not be effected, and Vadeni was soon recaptured by a Russian advance guard. By this time troops and supplies had been assembled for a violent assault on that part of the line offering the best chance of a successful crossing. Advancing over the dry ground toward Fundeni, the Teutons launched an offensive at the town shortly after the middle of January. The im- portance of this attack may be gauged from the fact that the best Prussian troops in the Teuton armies were thrown into the fighting. Day after day the struggle dragged on, and still the river barrier barred the way to Teuton ambition. February found the baffled armies of the Central Powers still fighting to cross the barrier, and the world began to realize that the marshy valley of the Sereth and Putna con- stituted a military obstacle of commanding importance. While suffering defeat in every attempt to turn the left wing or to break through the center of the Sereth-Putna line, the Teutons were not idle up in the mountains, where a successful advance would turn the right of the line and flank the defenders out of the entire position. For more than a month a colossal effort was made to break through the Oituz pass. To understand what success in this endeavor would mean, one must carefully note the pattern of the valleys in the vicinity of the pass. In the upper Trotus valley four branch ravines, converging upon the towa of Onesti, have more or less practicable passes near their heads. Thus the upper Trotus itself heads in Gyimes pass and carries a rail- road and highroad ; the upper Uz heads in an unimportant pass through which there runs a trail; the upper Oituz CONQUEST OP RUMANIA 201 forms the Oituz pass, >vhich has a good wagon road; and the upper Casinul starts at a minor pass provided with a trail. Now it is clear that if the Teutons succeeded in forcing Strategic any one of these passes and reached Onesti, the trunk supply at^^tu^ line would be cut and the forces defending the other passes pass would be trapped. But this is not all; for once the four passes were thrown open by such a successful manoeuver, and a Teuton army concentrated in the Trotus valley, backed by three good supply lines (a railroad and two wagon roads) through the Gyimes and Oituz passes, nothing could check a Teuton advance down valley to its junction with the Sereth. This would take in the rear all the northwestern extension of the Putna line and would cut the central Moldavian rail- way, the vital artery upon which all the rest of the Putna line depends. The moment this main railway was reached, a retreat to the northeast, behind the middle Sereth Kiver, would be forced. In other words, a success in one of the passes at the right of the Sereth-Putna line would outflank practically the entire position. No wonder the fighting at Oituz pass occupied the atten- Teutons tion of the world for a number of weeks ! Four Teuton ^^ moun- columns entered the heads of the four branch valleys and tainous all fought desperately to reach Onesti. The advance through Oituz pass seemed to promise the best advantage to the Teuton offensive, and would reach the Trotus valley railway only a few miles from the crest of the range. But the power of the defensive, blocking the narrow valleys, was too great. The column in the Casinul valley got within ten miles of its objective when it was thrown back. The other columns were even less successful. A furious attack on the secondary ridge farther southeast fared no better. Every attempt to reach the Trotus valley railway failed. The diflScult moun- tain topography prevented the turning of the Sereth-Putna 202 TOPOGRAPHY AND STRATEGY IN THE WAR line on the right just as effectively as the marshes near Galatz prevented the turning of the left. The Rumanian campaign, beginning on the defensive line of the Transylvanian Alps and Danube marshes, ended on the defensive line of the northern Transylvanian Alps and Sereth-Putna marshes. Many months were to pass by with the two opposing armies deadlocked along this same natural topographic barrier, and when the United States entered the world conflict it found this deadlock unbroken. GEOGRAPHIC INDEX GEOGRAPHIC INDEX Aa River, 116, 117 Adige River, 126, 128, 129-130, 134 Adrianople, 146, 147, 148, 151 Adriatic coast, 157, 158 Aire River, 6 Aisne, Battle of the, 37-40 Aisne River, 2, 4, 6, 37, 38, 39, 40 Aix-la-Chapelle, 23 Albania, 156, 157, 170 Allenstein, 58 Alpine passes, 129-130 Alps (Julian), 136-143 Alps (Trentine), 121-135; moun- tain warfare in, 130-132 Alsace, German operations in, 12, 13; invasion of, 11 Amatovo Lake, 172 Amiens, 30 Ampezzo basin, 133 Ampezzo pass, 129 Angerapp River, 64 Antwerp, 13 Archangel, 93 Ardennes Mountains, 10, 14, 16, 17, 18, 19, 23, 24, 27, 28, 39 Ardjan Lake, 173 Arges River, 195 Argonne Forest, 6-9 Arras, 30 Artois, 17 Asiago plateau, 135 Assa valley, 129 Astico valley, 129 AugustOw, 56, 67 ; battle of, 63 Austria - Hungary, campaigns against, 69-81, 128-143 Austro-Italian frontier,. 123-127 Austro-Russian frontier, 50-55, 60-61 Babit Lake, 117 Babuna pass, 171 Bainsizza plateau, 136, 138, 142, 143 Balkan ranges, 131, 144, 145 Balkan peninsula, 144-161; cam- paigns in, 162-176 Balta marshes, 182 Baltic Sea, 50, 55, 58, 88, 93, 94 Baranovitchi, 92, 95 Bekas pass, 180 Belfort, 13, 20, 21 Belfort gateway, 13, 20, 21 Belgium, German invasion of, 26- 30; routes of invasion of, 23- 25; terrain of, 13-19 Belgrade, 145, 146, 148, 149, 150, 152, 153, 162, 163, 164, 166, 182 Berlin, 55, 59, 60, 73 Berlin-to-Bagdad railway, 146. See also Orient railway. Berry-au-Bac, 40 Beshik Lake, 174 Beshik Mountains, 174 Biala River, 51, 73, 88, 89, 93, 95, 97 Bielostok, 90, 92, 111 Bihar Mountains, 179 Black Forest, terrain of, 11-13 Black Sea, 55, 73, 93, 94, 141, 179, 188, 190 Bobr River, 63, 64, 65, 66, 67, 105, 108, 109, 110 Bosnia, 144, 156, 159 Bosporus, 145 Bourg, 40 Bozen, 126 Braila, 199 Bregalnitza River, 155, 167 Brenner pass, 126, 128 Brenta River, 129 Brest-Litovsk, 56, 90, 107 Bromberg, 57 Brussels, 24 Bug River, 53, 54, 56, 65, 69, 70, 71, 96, 103, 104, 105, 111 Bukharest, 55. 73, 178, 180, 181, 187, 188, 192, 195, 196 Bukowina, terrain of, 75, 76 Bulgaria, 95, 150, 151, 152, 153, 155, 156, 167, 184, 185, 188 Butkovo River, 173 Butkovo Lake, 173 Buzeu, 196 Buzeu River, 178, 196, 197, 199 Bzura River, 56, 75, 85, 86, 89, 90 305 jMjm^iJ*