#THE MORAVA-YARDAR TRENCH

[sofiaburgas]

THE MORAVA-YARDAR TRENCH

The Maritza takes a direct course toward Constantinople for more than one hundred and fifty miles, then turns abruptly southward to the Mediterranean Sea. At this sudden bend in the river stands the fortified city of Adrianople. Except 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 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 sandbars 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-YARDAR 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-Yardar depression does not lead to the land bridge uniting Europe with Asia Minor, but it does serve as a most important 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. From southern Germany and the eastern Alps, the foothills of the Carpathians and the Alps of Transylvania, and from all of the great Hungarian basin, the valley routes lead straight to Belgrade, whence the Morava-Yardar valley cleaves a way through the mountains to the open waters beyond.

Ostrogoths entered northern Greece

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 of the Serb race is largely the story of a struggle for control of this vital artery of communication.

[bulgarianqueens]

THE MORAVA-YARDAR TRENCH

The Maritza takes a direct course toward Constantinople for more than one hundred and fifty miles, then turns abruptly southward to the Mediterranean Sea. At this sudden bend in the river stands the fortified city of Adrianople. Except 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 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 sandbars 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-YARDAR 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-Yardar depression does not lead to the land bridge uniting Europe with Asia Minor, but it does serve as a most important 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. From southern Germany and the eastern Alps, the foothills of the Carpathians and the Alps of Transylvania, and from all of the great Hungarian basin, the valley routes lead straight to Belgrade, whence the Morava-Yardar valley cleaves a way through the mountains to the open waters beyond.

Ostrogoths entered northern Greece

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 of the Serb race is largely the story of a struggle for control of this vital artery of communication.

[bulgariafun]

THE MORAVA-YARDAR TRENCH

The Maritza takes a direct course toward Constantinople for more than one hundred and fifty miles, then turns abruptly southward to the Mediterranean Sea. At this sudden bend in the river stands the fortified city of Adrianople. Except 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 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 sandbars 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-YARDAR 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-Yardar depression does not lead to the land bridge uniting Europe with Asia Minor, but it does serve as a most important 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. From southern Germany and the eastern Alps, the foothills of the Carpathians and the Alps of Transylvania, and from all of the great Hungarian basin, the valley routes lead straight to Belgrade, whence the Morava-Yardar valley cleaves a way through the mountains to the open waters beyond.

Ostrogoths entered northern Greece

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 of the Serb race is largely the story of a struggle for control of this vital artery of communication.

[bulgariastreets]

PEACEABLE CONQUEST OF THE MARITZA VALLEY

While the Morava River is navigable for small boats from the mouth half-way up to Nish, the upper Yardar is too full of rapids and its lower course too full of sand-bars 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 gorgelike proportions, it gives an unbroken channel-way clear through a rugged mountain barrier.

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 Bulgarian troops might bear the brunt of the fighting necessary to capture the remaining third from Serbian hands.

This was truly an ambitious plan, but certain considerations having a geographic basis made it possible for Germany to crown the program with success, and that with slight cost and incalculable profit to herself. The close of the second 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 disadvantages 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 is to the Mediterranean by way of the lower Maritza River; but the reconquest of Adrianople by the Turks led to a division of territory which forced Bulgarian goods en route downstream to the Bulgarian port of Dedeagatch to cross through a small section of Turkey.

[istanbulboatours]

Nish-Saloniki line at Uskub

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 River, which unites with the Western Morava, but which is not followed throughout its length by so much as a good wagon road. To the southeast 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 Yardar at Uskub. An important railway leaves the Nish-Saloniki line at Uskub 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-Yardar trench is well protected against invasion, whether 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.

THE CAMPAIGN FOR POSSESSION OF THE MORAVA-YARDAR 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 any considerable portion of the Morava-Yardar trench was apparently secondary. 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 pontoon bridges. For 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.

[thefishbread]

Mountainous region bordering the Western Morava

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 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 np 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 immediately appear that the Katchanik position was the 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 runs 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 tiskiib should succeed in breaking through the Katchanik gorge into the plain of Kosovo, they could strike north and east against the rear of the Serbian armies and convert retreat into disaster. Little wonder, then, that the “Katchanik Pass” figured so prominently in the war despatches during this period!

Key to the Serbian position

But if Katchanik was the key to the Serbian position, Yeles was the key to Katchanik. Should the Anglo-French troops coming up the Yardar from Saloniki capture Yeles 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 enclosing the Bulgarians in the valley between 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 defeated, they could retire northeastward into a region fully under their control. The threat would become imminent the moment Yeles fell to the Allies. Such were the topographic relations responsible for the rather striking fact that an Anglo-French attack upon Yeles relieved the pressure upon Serbian forces in the mountains far to the north.

[likesbulgaria]

Mediterranean from Bulgarian lands

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. With 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, and Bulgaria lent a willing ear to plans which promised immediate redress of past wrongs. Turkey was induced to 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 boundaries. As a further reward for direct action against Serbia, Bulgaria should receive the coveted section of the Morava-Yardar trench, the conquest of which would be rendered easy by Teutonic co-operation 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 Yardar valley. German diplomacy won, the geographic bargain was made, and from that moment there remained only the problem of forcibly seizing the Morava- Yardar trench.

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 compre-hensive campaign against the entire Morava-Yardar trench essential. In the first place, as we have just seen, the Yardar valley had to be secured for political reasons, since its possession by Bulgaria 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.

[yellowbg]

Nishava River

There are, nevertheless, certain pathways through the eastern barrier which might be forced by a foe possessing superior numbers. Chief among these is that segment of the great Morava-Maritza trench carved by the Nishava River, which unfortunately rises within Bulgarian territory, and flows directly through the barrier into the Morava-Yardar trench at the critically important junction near Nish.

To stop this gap the fortifications of Pirot just inside the Serbian 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 Ylasina, Kriva, and Bregalnitza Rivers, rising at or near the Serbo-Bul- garian boundary on the crest of the main range and flowing westward to the Morava and the Yardar, give access to the trench at Leskovatz basin, at Kumanovo, and in the Yeles-Krivolak region. Finally, the broadly open Strumitza valley, mainly in Bulgarian territory, but heading close to the lower Yardar, 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.

Protection afforded by difficult mountainous

It appears, therefore, that despite the protection afforded by difficult mountainous country east of the Morava-Yardar line, the trench was open to attack at a number of critical points, provided the invading forces were sufficiently large to overwhelm resistance and drive their columns through the narrow valleys. This danger was the more acute because 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 should be noted, furthermore, that the hostile territory flanks the Morava-Yardar trench throughout practically its entire length, usually lying not more than fifty miles distant, while near Yranye 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.

[tturkishcoffe]

Mountainous region bordering the Western Morava

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 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 np 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 immediately appear that the Katchanik position was the 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 runs 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 tiskiib should succeed in breaking through the Katchanik gorge into the plain of Kosovo, they could strike north and east against the rear of the Serbian armies and convert retreat into disaster. Little wonder, then, that the “Katchanik Pass” figured so prominently in the war despatches during this period!

Key to the Serbian position

But if Katchanik was the key to the Serbian position, Yeles was the key to Katchanik. Should the Anglo-French troops coming up the Yardar from Saloniki capture Yeles 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 enclosing the Bulgarians in the valley between 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 defeated, they could retire northeastward into a region fully under their control. The threat would become imminent the moment Yeles fell to the Allies. Such were the topographic relations responsible for the rather striking fact that an Anglo-French attack upon Yeles relieved the pressure upon Serbian forces in the mountains far to the north.

[goldenhornist]

Nish-Saloniki line at Uskub

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 River, which unites with the Western Morava, but which is not followed throughout its length by so much as a good wagon road. To the southeast 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 Yardar at Uskub. An important railway leaves the Nish-Saloniki line at Uskub 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-Yardar trench is well protected against invasion, whether 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.

THE CAMPAIGN FOR POSSESSION OF THE MORAVA-YARDAR 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 any considerable portion of the Morava-Yardar trench was apparently secondary. 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 pontoon bridges. For 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.

[lifestylehotels]

Mountainous region bordering the Western Morava

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 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 np 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 immediately appear that the Katchanik position was the 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 runs 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 tiskiib should succeed in breaking through the Katchanik gorge into the plain of Kosovo, they could strike north and east against the rear of the Serbian armies and convert retreat into disaster. Little wonder, then, that the “Katchanik Pass” figured so prominently in the war despatches during this period!

Key to the Serbian position

But if Katchanik was the key to the Serbian position, Yeles was the key to Katchanik. Should the Anglo-French troops coming up the Yardar from Saloniki capture Yeles 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 enclosing the Bulgarians in the valley between 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 defeated, they could retire northeastward into a region fully under their control. The threat would become imminent the moment Yeles fell to the Allies. Such were the topographic relations responsible for the rather striking fact that an Anglo-French attack upon Yeles relieved the pressure upon Serbian forces in the mountains far to the north.

[airaglub]

Long as Serbia and her allies

To cut it was to deprive those armies of reinforcements, munitions, and other supplies coming from the south. Furthermore, possession of the Morava-Maritza trench would never be secure so long as Serbia and her allies held the Yardar depression, for at any moment they might launch a bolt along this natural groove which would sever the Orient Railway at Nish and thus undo all that had been accomplished through the new alliance with Bulgaria. For the Teuton-Bulgar forces the capture of the combined Morava and Yardar valleys was a single military problem. Let us examine the physiographic features which serve as natural defenses of this important trench.

The Northern Defenses. The Morava valley is widely open to the north and is there bounded on both sides by comparatively low hills. An enemy securing a foothold in the rolling country to the east 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 provided 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 southward, rise into a wild, mountainous highland.

South of Mitrovitza

The Save is a late-mature river swinging in great meanders 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 lowland 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 peninsula between the Drina and the Save is called the Matchva and is famous for its inhospitable character. In volume 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 sand-bars. At no point is the stream fordable, and at Belgrade alone is it crossed by a bridge.

[bgtraveldays]

Nishava River

There are, nevertheless, certain pathways through the eastern barrier which might be forced by a foe possessing superior numbers. Chief among these is that segment of the great Morava-Maritza trench carved by the Nishava River, which unfortunately rises within Bulgarian territory, and flows directly through the barrier into the Morava-Yardar trench at the critically important junction near Nish.

To stop this gap the fortifications of Pirot just inside the Serbian 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 Ylasina, Kriva, and Bregalnitza Rivers, rising at or near the Serbo-Bul- garian boundary on the crest of the main range and flowing westward to the Morava and the Yardar, give access to the trench at Leskovatz basin, at Kumanovo, and in the Yeles-Krivolak region. Finally, the broadly open Strumitza valley, mainly in Bulgarian territory, but heading close to the lower Yardar, 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.

Protection afforded by difficult mountainous

It appears, therefore, that despite the protection afforded by difficult mountainous country east of the Morava-Yardar line, the trench was open to attack at a number of critical points, provided the invading forces were sufficiently large to overwhelm resistance and drive their columns through the narrow valleys. This danger was the more acute because 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 should be noted, furthermore, that the hostile territory flanks the Morava-Yardar trench throughout practically its entire length, usually lying not more than fifty miles distant, while near Yranye 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.

[turkishhamam]

Nish-Saloniki line at Uskub

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 River, which unites with the Western Morava, but which is not followed throughout its length by so much as a good wagon road. To the southeast 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 Yardar at Uskub. An important railway leaves the Nish-Saloniki line at Uskub 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-Yardar trench is well protected against invasion, whether 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.

THE CAMPAIGN FOR POSSESSION OF THE MORAVA-YARDAR 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 any considerable portion of the Morava-Yardar trench was apparently secondary. 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 pontoon bridges. For 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.

[pubmusiclife]

Bulgarian hands and Bulgarian attacks

The strategic value of Yeles was fully appreciated by the Bulgarian commanders, and heavy reinforcements were evidently poured into the Yardar trench at that point. All efforts of the Allied armies failed to achieve their purpose; Yeles remained in Bulgarian hands and Bulgarian attacks on the poorly equipped Serbs defending Katchanik gorge proceeded without serious interruption. When it became apparent 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.

All danger to the Teutonic occupation of the Morava- Yardar trench north of Yeles was thus removed, and the remainder of the campaign consisted in squeezing the remnants 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 exceeding 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.

Yardar valley toward Veles

When the French and English pushed up the Yardar valley toward Veles they seized as their base for a great armed camp the triangle of mountainous ground lying between the Yardar Biver 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 Trinok 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 disadvantage which ultimately compelled its evacuation. Both the mountain ridges and the river trenches afforded admirable natural defenses. The gorge of the Tsrna is steepsided 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 the Bulgars from getting into Monastir basin. For defensive purposes the larger Yardar Biver, protecting the east side of the triangle, was strategically important, because it is both wide and unfordable and its valley is steepsided,—in one place a veritable gorge.

[travelplannerbg]

Mediterranean from Bulgarian lands

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. With 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, and Bulgaria lent a willing ear to plans which promised immediate redress of past wrongs. Turkey was induced to 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 boundaries. As a further reward for direct action against Serbia, Bulgaria should receive the coveted section of the Morava-Yardar trench, the conquest of which would be rendered easy by Teutonic co-operation 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 Yardar valley. German diplomacy won, the geographic bargain was made, and from that moment there remained only the problem of forcibly seizing the Morava- Yardar trench.

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 compre-hensive campaign against the entire Morava-Yardar trench essential. In the first place, as we have just seen, the Yardar valley had to be secured for political reasons, since its possession by Bulgaria 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.