Second Austro-Hungarian invasion of Serbia

On 8 September 1914 the troops of Austria-Hungary entered Serbia for the second time. The first units tried to cross the border river, the Drina, as early as 7 September, and the main crossings took place during the night of 7/8 September and over the following day. Less than three weeks earlier the same army had fled from Serbia after its defeat on Mount Cer.

Potiorek wants revenge

The commander of the Austro-Hungarian forces in the Balkans, General Oskar Potiorek, was at the same time Governor of Bosnia and Herzegovina. He had been responsible for Archduke Franz Ferdinand’s safety on the day of the assassination in Sarajevo, and the August defeat in Serbia had further damaged his standing. Potiorek wanted a victory as soon as possible, even though his forces had shrunk. The Second Army, which had fought on the Sava in August, had been taken away from him and moved to Galicia, against the Russians. He was left with two armies: the Fifth Army of General Liborius von Frank and the Sixth Army, which he commanded himself.

The Serbian offensive in the north gave him his opportunity. On 6 September, under pressure from Russia and France, the Serbs crossed the Sava and entered Austro-Hungarian Syrmia. Potiorek decided that the best response would be a blow from the west, across the Drina, deep into Serbia. If his armies threatened the heart of the country, the Serbs would have to turn their troops back from Syrmia.

Two armies on the Drina

The Fifth Army attacked on the lower Drina, into the lowland Mačva, where the fighting for Mount Cer had taken place in August. General Stepa Stepanović’s Serbian Second Army was waiting for it in prepared positions. Many crossings collapsed under the defenders’ fire, and some units had to return to the Bosnian bank.

The stronger Sixth Army crossed the river further south, between Zvornik and Ljubovija (PL). Here surprise favoured the Austro-Hungarians. The weaker Serbian Third Army could not stop them, and mountain brigades began climbing the ridges rising above the Drina valley.

The plan works, but only in part

In one respect Potiorek’s plan worked. Vojvoda Radomir Putnik, chief of staff of the Serbian army, ordered the withdrawal from Syrmia on 11 September and sent the First Army’s troops to the Drina front. The Serbian offensive on enemy territory ended after a few days.

The second invasion, however, brought Austria-Hungary no decision. Fierce fighting broke out in the mountains above the Drina and turned into a long trench war. The front froze until November, when Potiorek launched his third and largest offensive against Serbia.