The Austro-Hungarian Armed Forces occupied Serbia from late 1915 until the end of World War I. Austria-Hungary's declaration of war against Serbia on 28 July 1914 marked the beginning of the war. After three unsuccessful Austro-Hungarian offensives between August and December 1914, a combined Austro-Hungarian and German offensive breached the Serbian front from the north and west in October 1915, while Bulgaria attacked from the east. By January 1916, all of Serbia had been occupied by the Central Powers.
Serbia was divided into two separate occupation zones, an Austro-Hungarian and a Bulgarian zone, both governed under a military administration. Germany declined to directly annex any Serbian territory and instead took control of railways, mines, and forestry and agricultural resources in both occupied zones. The Austro-Hungarian occupation zone covered the northern three-quarters of Serbia. It was ruled by the Military General Governorate of Serbia (MGG/S), an administration established by the Austro-Hungarian Army on 1 January 1916 with a military governor at its head, seconded by a civil commissioner. Emperor Franz Joseph I appointed Johann von Salis-Seewis, an officer born in Croatia, as the first Military Governor General. The goal of the new administration was to denationalise the Serb population and turn the country into a territory from which to draw food and exploit economic resources.
In addition to a military legal system that banned all political organizations, forbade public assembly, and brought schools under its control, the Austro-Hungarian Army was allowed to impose martial law, practice hostage-taking, burn villages in punitive raids and respond to uprisings with public hangings and summary executions. During the occupation, over 50,000 Serbian civilians were deported to purpose-built internment and concentration camps in Austria-Hungary, most notably Mauthausen in Austria, Doboj in Bosnia, and Nagymegyer, Arad and Kecskemét in Hungary.
In September 1918, Allied forces, spearheaded by the Serbian Second Army and the Yugoslav Volunteer Division, broke through the Salonica front, leading to the surrender of Bulgaria on 30 September, followed by the quick liberation of Serbia and the retreat of all remaining Austro-Hungarian troops by the end of October. By 1 November 1918, all of pre-war Serbia had been liberated, bringing the occupation to an end.
Background
On 28 June 1914, the heir to the Habsburg throne, Archduke Franz Ferdinand, was assassinated by Bosnian Serb student Gavrilo Princip in Sarajevo. The preservation of Austria-Hungary's prestige necessitated a punishing attack on Serbia, which the Austro-Hungarian leadership deemed responsible for the murder. The Austro-Hungarian military leadership was determined to quash Serbia's independence, which it viewed as an unacceptable threat to the future of the empire given its sizeable South Slavic population.
On 28 July 1914, exactly one month after Franz Ferdinand's assassination, Austria-Hungary declared war on Serbia. That evening, Austro-Hungarian artillery shelled the Serbian capital of Belgrade from the border town of Semlin (modern-day Zemun), effectively starting World War I. Command of the Austro-Hungarian invasion force was delegated to Feldzeugmeister Oskar Potiorek, the Governor-General of Bosnia and Herzegovina, who had been responsible for the security of Franz Ferdinand and his wife Duchess Sophie of Hohenberg in Sarajevo. On the morning of 12 August 1914, the Austro-Hungarian Fifth Army crossed the Drina River, effectively starting the first invasion of Serbia.
Punitive expedition and first occupation
During the first invasion of Serbia, which the Austro-Hungarian leadership euphemistically dubbed a punitive expedition (German: Strafexpedition), Austro-Hungarian forces occupied parts of Serbia for thirteen days. Their war aims were not only to eliminate Serbia as a threat but also to punish her for fuelling South Slav irredentism in the Monarchy. The occupation turned into a war of annihilation, accompanied by massacres of civilians and the taking of hostages. Austro-Hungarian troops committed a number of war crimes against the Serbian population, especially in the area of Mačva, where according to historian Geoffrey Wawro the Austro-Hungarian army savaged the civilian population in a wave of atrocities. During the short occupation between 3,500 and 4,000 Serb civilians were killed in executions and acts of random violence by marauding troops.
Mass killings took place in numerous towns in northern Serbia. On 17 August 1914, in the Serbian town of Šabac, 120 residents—mostly women, children and old men, who had previously been locked in a church—were shot and buried in the churchyard by Austro-Hungarian troops on the orders of Feldmarschall-Leutnant Kasimir von Lütgendorf. The remaining residents were beaten to death, hanged, stabbed, mutilated or burned alive. A pit was later discovered in the village of Lešnica containing 109 dead peasants who were "bound together with a rope and encircled by wire"; they had been shot and immediately buried, even with some still alive. Wawro writes that in Krupanj, men of the 42nd Home Guard Infantry Division, the exclusively Croat formation known as the Devil's Division, bashed a group of old men and boys to the ground using rifle buttstrokes and then hanged any who were still breathing.
These types of attacks were planned at the highest level, the ground for the escalation of violence was ideologically prepared by the commanders' verbal radicalism, on August 13 Potiorek ordered reprisal hangings, the taking of hostages and arson by all units. Often bodies were left hanging on the gallows, trees or street lamps for days as a deterrent and as evidence of the Austro-Hungarian military's determination to deal with Serbian suspects. Many executions were photographed by Austro-Hungarian soldiers and officers; some of the images were reproduced as postcards and sold through the Austro-Hungarian army's official sales outlets. The Swiss criminologist and physician Archibald Reiss reported on the atrocities committed by the Austro-Hungarian army in a report that was presented at the Paris Peace Conference of 1919, Reiss recorded that the number of civilians killed in the invaded Serbian territory amounted to between 3,000 and 4,000, including a large number of women and children, in the region around Šabac he counted 1,658 burned buildings. According to historian James Lyon, "the Habsburg forces engaged in an orgy of looting, rape, murder, mass extermination, and other atrocities". Reiss likened the Austro-Hungarian atrocities to the Rape of Belgium.
American war correspondent John Reed, touring Serbia with Canadian artist Boardman Robinson, reported stories about the atrocities committed by Austrian soldiers against the civilian population "We saw the gutted Hôtel d’Europe, and the blackened and mutilated church in Šabac where three thousand men, women and children were penned up together without food or water for four days, and then divided into two groups – one sent to Austria as prisoners of war, the other driven ahead of the army as it marched south against the Serbians".
Austrian historian Anton Holzer wrote that the Austro-Hungarian army carried out "countless and systematic massacres…against the Serbian population. The soldiers invaded villages and rounded up unarmed men, women and children. They were either shot dead, bayoneted to death or hanged. The victims were locked into barns and burned alive. Women were sent up to the front lines and mass-raped. The inhabitants of whole villages were taken as hostages and humiliated and tortured." According to various sources, 30,000 Serbian civilians were executed during the first year of occupation alone.
On 24 August, after delivering a major defeat to Austria-Hungary's invading "Balkan Armed Forces" (German: Balkanstreitkräfte) at the Battle of Cer, the Royal Serbian Army liberated Šabac and reached the frontier banks of the Sava River, thereby bringing the first Austro-Hungarian invasion of Serbia to an end, and securing the first Allied victory of World War I.
Repulsed invasions and Serbian victory
On 8 September 1914 the Austro-Hungarians launched a second invasion, a twin-pronged night attack across the Drina to secure a firm bridgehead. This time engaging all their forces the well-equipped Habsburg forces outnumbered the Serbs who were short of munitions two to one. Facing fierce resistance, the Fifth Army was pushed back into Bosnia while the Sixth Army's offensive was stopped by a strong Serbian counterattack. On 23 October, the flagship of the Austro-Hungarian Danube Flotilla, the SMS Temes, which had shelled Belgrade on the first day of the war, was sunk by a mine on the Sava. Although it suffered nearly 30,000 casualties and the invasion was temporarily halted, the Austro-Hungarian army retained a foothold in Serbia.
Convinced that Serbia was near defeat, Potiorek regrouped and launched a third offensive on 5 November 1914. Potiorek exploited the Austro-Hungarians' superiority in artillery, including large calibre mortar, to capture Valjevo on 15 November and with support from a monitor group of the Danube Flotilla as well as aerial reconnaissance, Belgrade on 30 November, forcing the Royal Serbian Army to retreat.
The conquered territory was divided into five county commands (German: Etappenbezirkskommandos). The Austro-Hungarian Feldmarschall of Croatian ethnicity Stjepan Sarkotić, commander during the first invasion of the 42nd Home Guard Infantry Division, was appointed governor-general of Serbia by Emperor Franz Joseph on 24 November 1914. Under Sarkotić's administration, multiple concentration camps were established in which tens of thousands of Serbs were interned; in the town of Šabac alone, between 1,500 and 2,000 civilians were deported to internment camps in Hungary. According to the historian Bastian Matteo Scianna, the Austro-Hungarian atrocities had a planned exterminatory character.
In early December, the Royal Serbian Army launched a sustained counterattack, decisively defeating the Austro-Hungarians at the Battle of Kolubara and recapturing Belgrade a day after General Sarkotic's new military government had been established. By 15 December, the Royal Serbian Army had captured Zemun, having crossed the border in pursuit of the Austro-Hungarians. Defeat at the hands of Serbia, a small Balkan peasant kingdom, wounded the pride of Austria-Hungary's military and civilian leadership. One Austrian officer was reported as saying that Potiorek would be shot if he appeared among his own troops. On 22 December, Potiorek was relieved of his command and replaced by Archduke Eugen of Austria. Although Austria-Hungary had failed to defeat Serbia, the Royal Serbian Army had exhausted its military capability, losing 100,000 men in battle, and was forced to deal with a typhoid epidemic that further decimated the army and civilian population.
German officials urged their Austro-Hungarian counterparts to launch yet another offensive against Serbia, despite the fact that the Austro-Hungarians were engaged in a costly second front with Russia to the east. The Austro-Hungarian leadership would not consider invading Serbia again for almost a year, when Bulgarian participation in such an invasion was guaranteed.
Conquest of Serbia
On 6 September 1915, Germany and Bulgaria entered into a secret military alliance. German officials promised Bulgaria all of Serbian Macedonia, parts of northeastern Serbia, as well as a new loan of 200,000,000 gold francs in return for Bulgaria's participation in an upcoming invasion of Serbia. The agreement was signed in the German town of Plessa. The Central Powers enjoyed massive superiority in numbers and equipment, especially in artillery, along the nearly 1,000-kilometre (620 mi) front. Serbia and Montenegro could hardly muster half the number of soldiers as the Central Powers.
On 5 October 1915, Austria-Hungary and Germany launched a joint invasion of Serbia. The offensive marked Austria-Hungary's fourth attempt to conquer Serbia, this time led by German General August von Mackensen. On that day, a heavy artillery bombardment from the border with Serbia began. The next day three German and three Austro-Hungarian Army corps crossed the Sava, attacking from the north as part of Army Group Mackensen. On 9 October, Belgrade, Serbia's capital, was evacuated, on the same day, Austrian forces entered the neighbouring and allied country of Montenegro.
On 14 October, with the bulk of the Serbian forces opposing combined invaders up north, two Bulgarian armies invaded southern Serbia from the east, advancing towards Niš and Skoplje. On 21 October Skopje is occupied by Bulgarian troops effectively cutting off the Serbian Army's lines of communication to the south as well as a retreat route towards French General Maurice Sarrail's relief force, which had advanced northwards up the Vardar River valley from the Allies' new base in Salonica.
Despite the treaty of mutual assistance with Serbia against a Bulgarian attack, King Constantine of Greece refused to let the Greek army enter the war to aid the Serbs or let the Allies use the Greek railroads devoted to supporting their mobilization. On 27 October, the Germans entered the town of Knjaževac, the entire Serbian government moved its headquarters from Niš to Kraljevo; on 2 November the Serbian government moved again this time from Kraljevo to Mitrovica in Kosovo. On 5 November, Niš was taken by the Bulgarians who had connected General Gallwitz's Eleventh German Army. Avoiding encirclement and the trap set up by Mackensen, the Serbian army withdrew to Kosovo, on 22 November Putnik ordered a retreat.
Within six weeks, Austria-Hungary, Bulgaria and Germany had succeeded in conquering Serbia. While the strategic goals set before the offensive had been achieved, the Central Powers were deprived of a decisive victory by the Royal Serbian Army's winter retreat over the mountains of Albania and Montenegro towards the Adriatic coast. Ultimately, around 140,000 Serbian soldiers and hundreds of thousands of civilians were evacuated to the Greek island of Corfu, among them the entire Serbian government, as well as the Serbian royal family.