Start of the Austro-German offensive. Fall of Belgrade
During September 1915, in order to mislead the Serbian command, the German artillery fired several times on the Serbian banks of the Danube and Sava. On October 5-6, 1915, actual artillery preparation by the Mackensen armies began in order to prepare the crossing. On October 7, the Austro-German troops, with the support of the Danube Flotilla, began the crossing. From Bosnia, Austro-Hungarian troops attacked Montenegro, pinning down its army so that it could not, as during the 1914 campaign, attack the flank of the Austro-German army.
The crossing of the Austro-German troops near Belgrade turned out to be long and replete with obstacles, they had to take a well-fortified and favorable for defense, in its natural position, a bridgehead. The crossing was hampered by the need to clear the fairways of both rivers from minefields. In addition, a hurricane began that lasted more than a week. He scattered and damaged some of the ships and in some places cut off the landed vanguard from the main forces. However, the forward units were so strengthened that they withstood Serbian counterattacks even without the support of the main forces. An important role in the success of the Austro-German waxes was played by heavy artillery, which suppressed most of the Serbian artillery and destroyed the fortifications. An important role in the crossing was also played by the ships of the Danube Flotilla, supporting the landing troops with fire, suppressing the Serbian batteries. The Austro-German troops used searchlights that helped sweep mines at night, blind the enemy's searchlights, illuminated targets for artillery and covered the crossing troops with a light curtain.
Transport of troops across the Danube
The plan of operations provided for the transition of the Austro-German through the Drina, Sava and Danube. At the same time, the 3rd Army had to cross its right flank, with a force of one and a half divisions, which was joined by the Bosnian Visegrad group, overcoming the knee formed by the Drina and Sava in Machva, and also crossing the Sava with the help of steam ferries under the cover of fire monitors and armed steamers Danube flotilla. With its center (three divisions of the Austro-Hungarian 14th Corps), the 3rd Army was supposed to cross the Sava near Progar on the night of October 7 by ferries and over a military bridge under the cover of the ships of the Danube Flotilla. On October 7, the troops of the 14th corps were to build a pontoon bridge at Bolevtsy. On the left flank, the 26th Austro-Hungarian Division was to cross Sava at Ostruznica in order to distract the Serbs, and the 22nd German Reserve Corps was to force Sava above the Big Gypsy Island in order to cover the Serbian capital from the southwest. German troops were to participate in the capture of Belgrade and join up with the 8th Austro-Hungarian corps, advancing from Zemlin. An important role at the beginning of the operation was to be played by the Austro-Hungarian Danube Flotilla under the command of Captain 1st Rank Karl Lucich.
The German 11th Army was to cross the Danube simultaneously in three columns: at Palanca and Bazias, the 10th Reserve Corps was advancing on Ram; at Dunadombo - the 4th reserve corps across the Danube island of Temesziget to Kostolaki, and from Kevevar the 3rd reserve corps in the direction of the old Turkish fortress of Semendria. Down the river near Orsova, the Austrian group of General Fühlonn was supposed to operate. The Orsovo group performed mainly a demonstrative task. She was supposed to misinform and pin down the Serbian troops. Then she had to establish contact with the Bulgarians and, together with the 1st Bulgarian Army, occupy the protrusion of Serbian territory in the Danube bend at Kladovo in order to ensure free navigation along the Danube.
Field Marshal August von Mackensen
The offensive of the 3rd Austro-Hungarian Army. The Kövess army spent five days on the crossing, as the Serbian army stubbornly defended its capital. The Austro-German artillery carried out a powerful artillery barrage. So, at noon on October 6, the heavy artillery of the 8th Austro-Hungarian corps began preparing the crossing with a four-hour hurricane fire from 70 heavy and medium and 90 light guns. This was followed by shrapnel fire to suppress attempts to rebuild Serb batteries.
The 8th Austrian Corps had to cover the longest route by water, about 4 km, from the Zemlin region to Belgrade. His headquarters made a planning error and the first echelon of the 59th Infantry Division instead of the time scheduled for landing at 2 hours 50 minutes. approached the Serbian coast at 4 o'clock. And the artillery preparation ended according to plan at exactly 2 o'clock. 50 minutes Therefore, the Austrian units had to land without artillery support. As a result, and also because of the strong resistance of the Serbs, the crossing was difficult. In addition, the rising water in the rivers flooded the islands at the mouth of the river. Sava and low-lying areas of the Danube coast, which worsened the conditions for disembarkation and did not allow the telegraph cable to be supplied to the Serbian coast. The landed vanguard was left without communication and could not report the need for artillery support. This led to the fact that the forward shock battalions suffered significant casualties in men and materiel.
Only on October 9 did the steamships approach and, following the troops of the 59th Infantry Division, transported the 57th Infantry Division, which allowed the Austro-German troops to finally capture Belgrade. Shock groups of the Austro-Hungarian troops rushed from the north into the city and the fortress of Belgrade, took the citadel and Vracharskie heights.
The 22nd German Reserve Corps reached the Sava River on the evening of October 6. Serbian troops were at the heights of Banovo, which so rose above the opposite bank that approaching the river during the day along the low and very swampy left bank of the river. Sava was extremely difficult. Therefore, the troops began to cross the river at night. Behind the small islands off the Austrian coast, pontoons brought by the pioneers (sappers) were hidden in advance, 10-15 pieces for each crossing regiment. The landing of troops on the pontoons began after 2 o'clock. nights of October 7. Within 15-20 minutes. the first echelons have already landed on the Serbian coast and on the Gypsy island. The rest of the troops followed. While the troops were crossing at night, the losses of the German troops were small, but at dawn the Serbian artillery intensified and they increased greatly. Having lost up to two-thirds of the pontoons, the German troops at about 8 o'clock. in the morning, the crossing was suspended.
The advanced units (approximately one battalion per regiment) had to withstand Serbian counterattacks all day. The Germans and Austrians were saved by the fact that the main forces of the Serbian army had not yet managed to regroup from the Bulgarian direction. The crossing was resumed only in the evening, but with greater losses than on the first day. On October 8, the 208th right-flank reserve regiment occupied the first line of the Serbian position and went into the rear of the Serbs defending the Gypsy Island, which forced them to hastily retreat. As a result, the 207th Infantry Regiment was able to capture the serviceable Serbian bridge connecting the Gypsy Island with the coast. This made the crossing easier. Then the German troops went to storm the steep Banovski heights. A few hours later, thanks to the strong support of heavy artillery, the German troops broke the resistance of the Serbs.
Thanks to this success, on October 9, the 43rd German reserve division took the suburb of Belgrade - Topcidere. On the same day, after heavy street fighting, Austrian troops took Belgrade. Defending the city, about 5 thousand Serbs were killed. Many residents of the capital and people from other places, remembering the atrocities of the past Austro-Hungarian invasion, when civilians did not stand on ceremony, robbed, raped and killed, left their homes and joined the retreating army. The catastrophe began. The country was crumbling before our eyes.
Thus, on the third day of the operation, the Austro-German troops took the Serbian capital - Belgrade. However, the crossing at Belgrade was delayed and was completed instead of one in three days. The wrong calculation of the crossing by the Austro-German command could turn the whole enterprise into failure, if not for the persistence of the Germans, who broke the resistance of the Serbs with great losses for themselves, as well as the weakness of the Serbian army in the Belgrade direction and the complete superiority of the Austro-German troops in heavy artillery.
Source: N. Korsun Balkan Front of the World War 1914-1918.
The offensive of the 11th German army. The crossing of the 11th German army was prepared already in the spring-summer of 1915. Austrian sappers conducted reconnaissance of the river, completed fortification of positions on their bank, fixed roads and bridges. Reconnaissance revealed that the section from the mouth of the river is more convenient for crossing. Karas to Bazias, which allowed for a covert concentration of troops and watercraft. The crossing was planned at once in four places: the mouth of the river. Karasa, Snake Island, the mouth of the river. Nera and Bazias. It was planned to build a bridge using the Serpent Island.
All these places were carefully studied and prepared for the crossing, taking into account the weather conditions, the state of the water level and the likely actions of the Serbian troops. The estuaries of the Karas and Nera rivers were cleared of sediments and mines, and their fairway was deepened by blasting operations so that boats and pontoons could pass there. In addition, the engineering services prepared a dense network of roads in the places of the initial location of the troops, put up signs for the troops and set up observation posts. A feature of the landing of troops in this area was a hurricane, which interrupted regular navigation for several days and interfered with sweeping operations.
Before the start of the operation, Austrian sappers raised eight barges that sank beyond the island of Ponyavica, and a steamer sunk by Serb artillery at St. Moldova. With great effort, the barges were raised and fixed, placing them on the coast of the island of Ponyavica under the cover of forest and bushes. The steamer was also raised and transported to the island of Ponyavica, covered with trees. In addition, the Germans at night threw about 100 half-pontons, which were lowered along the river. Karasu to its mouth, and then along the river. Danube to the Serpent Island, where they were dragged ashore and sheltered. The crossing was also provided by Austrian rowing ships, divisional and hull German bridge ferries.
The immediate goal of the German troops after the crossing was the capture of the Goritsy region and the Orlyak massif (south of Goritsa), and then the Klitsevan, Zaton'e line. The advanced troops were carrying ammunition for five days, provisions for six days, and large reserves of engineering equipment. This was a very reasonable decision, since the unleashing elements led to a break in the crossing.
Thus, the Austrians and Germans carefully prepared for the crossing of the water barrier. At the same time, all these preparations were carried out so secretly that the crossing on October 7 was unexpected for the Serbs.
On October 6, 1915, German artillery began shelling Serbian positions and by the morning of October 7, the fire was brought to the level of a hurricane. Despite the powerful fire of almost 40 batteries, which continued until the 10th Corps advance echelon, advancing from the Serpent Island, landed, the Serbs, after the Germans had transferred artillery fire inland, put up strong resistance at Ram. By the evening of October 7, two regiments of the 103rd Infantry Division were transported.
Then the German troops had to go through difficult days. On October 8 and 9, it was pouring rain, which turned into a storm. The hurricane continued until October 17. At this time, all means of crossing, except for the steamer, were inactive. A number of watercraft were damaged by the hurricane wind. At the same time, the Serbs fired heavy artillery fire, and launched a counterattack, trying to throw the Germans into the river. The steamer with great difficulty completed the transfer of the troops of the 103rd division. Only additional stocks of ammunition, food and various equipment allowed the Germans to survive. The storm ended only on October 17 and the remaining troops of the 10th German Corps were transferred to the other side. On October 21, the Germans built two bridges.
Thus, the thorough preparation of the operation allowed the German 11th Army to successfully cross the river, despite the 8-day hurricane. The Germans, with the help of powerful crossing means, without building a bridge, transferred such large and well-equipped units that they were able to repel all enemy counterattacks and hold out until the main forces approached.
Further offensive by Mackensen's troops
The Serbian command began to regroup its forces from the Bulgarian direction to the north with the aim of creating a strong defense on the path of the Austro-German troops. Austro-German troops, which delayed the crossing more than planned, by October 18 were able to advance on the southern bank of the river. The Danube is only 10 km away. The 19th Austro-Hungarian Corps, advancing in the Bosnian direction, overcoming stubborn resistance from the Montenegrin army, also advanced slowly.
On October 21, the vanguards of Mackensen's armies were on the Ripan, Kaliste line, and the Austro-Hungarian troops, which crossed the Lower Drina, reached Sabac. The offensive of the Austro-German troops proceeded with great difficulty, especially due to the lack of communication lines. The existing roads were damaged by autumn rains. The Austro-German troops were no longer delayed by the resistance of the Serbian troops, but by the dirt and roads clogged with people.
It was especially difficult for the 3rd Austro-Hungarian Army of Kövess, which was worse than the 11th Army in overcoming the resistance of the Serbs. The German High Command suggested that the Austrians strengthen the 3rd Army at the expense of troops from the Italian front. However, the Austrians were afraid of a new offensive by the Italian army and refused to the Germans. Indeed, on October 18, the third offensive of the Italian army began (the third battle of the Isonzo). However, the Italians were unable to help Serbia. All the attacks of the Italian divisions crashed against the powerful defenses of the Austrian army. The Austrians were ready for an enemy attack. The Italians laid down many soldiers, but made little progress. In November, the Italian army launched a fourth offensive against the Isonzo. Fierce fighting continued until December, all attempts by the Italian army were unsuccessful. To break through the strong Austrian defenses, which took place in the mountainous terrain, the Italians had catastrophically little heavy artillery.
On the left flank of the Austro-German Army Group Mackensen, the situation was also difficult. The weak Austrian group of Fühlonn, located at Orsova, did not manage to cross the Danube at the beginning of the operation. As a result, the Austrians were unable to immediately ensure the junction between the 11th German and 1st Bulgarian armies, and the transportation of various supplies and materials along the Danube to Bulgaria. And the Bulgarian army depended on supplies from Austria and Germany.
Only on October 23, the Austrians in the area of the city of Orsovs were able to organize a powerful artillery barrage, with the participation of 420-mm guns. Hurricane artillery fire destroyed the Serbian fortifications. Under the cover of strong artillery and machine-gun fire (the width of the Danube near Orsova made it possible to conduct effective machine-gun fire on the other side), the Austrian troops were able to cross the river and gain a foothold. After the arrival of reinforcements, the Austrians continued their offensive and captured the necessary bridgehead. Thus, with the help of strong artillery and machine-gun fire, the Austro-Hungarian group Fyulonna was able to break the resistance of the Serbian troops and cross the Danube.
Bulgaria enters the war
On October 15, Bulgarian troops crossed the Serbian border. At first, the Bulgarian troops met fierce resistance from the Serbs and advanced rather slowly. For a long time, the Bulgarians unsuccessfully attacked the well-fortified positions of the Serbian army on the river. Timoke and north of Pirot. But on the left flank, Bulgarian troops were able to raid the Vranja station, where they destroyed the railway and telegraph, cutting off Serbia's communications with the Allied forces in Thessaloniki.
By October 21, the 1st Bulgarian Army continued to storm Serbian positions. The right wing and center of the Bulgarian army was located on the river. Timok between Zaychar and Knyazhevats, and the left wing fought at Pirot. Only on October 25 did the Bulgarian troops force the Serbs to withdraw beyond Timok. The 2nd Bulgarian Army easily reached the Vranja and Kumanov area, and intercepted the river with its left flank. Vardar near Veles. Thus, the Bulgarian troops interrupted the connection between the Serbian army and the allied expeditionary corps in Thessaloniki. This jeopardized the coverage of the main body of the Serb army.
