Battle of Cer

Battle of Cer
	Part of the Serbian campaign of the Balkans theatre of World War I
	; Map of Austro-Hungarian and Serbian troop movements, August 1914
Date	15–24 August 1914
Location	Cer Mountain and surrounding areas, northwestern Kingdom of Serbia44°33′16″N 19°31′41″E / 44.55444°N 19.52806°E
Result	Serbian victory
Belligerents
Kingdom of Serbia	Austria-Hungary
Commanders and leaders
Radomir Putnik; Stepa Stepanović; Pavle Jurišić Šturm	Oskar Potiorek; Eduard von Böhm-Ermolli; Liborius Ritter von Frank
Units involved
2nd Army; 3rd Army	2nd Army; 5th Army
Strength
180,000	200,000
Casualties and losses
Total: 18,000–20,000 3,000–5,000 killed; 15,000 wounded; ;	Total: 40,500–45,500 6,000–10,000 killed; 30,000 wounded; 4,500 captured; ;
	Battle site on a map of modern Serbia Battle site on a map of the Balkans

The Battle of Cer was a military campaign fought between Austria-Hungary and Serbia in August 1914, starting three weeks into the Serbian Campaign of 1914, the initial military action of the First World War. It took place around Cer Mountain and several surrounding villages, as well as the town of Šabac.

The battle, part of the first Austro-Hungarian invasion of Serbia, began on the night of 15 August when elements of the Serbian 1st Combined Division encountered Austro-Hungarian outposts that had been established on the slopes of Cer Mountain earlier in the invasion. The clashes that followed escalated into a battle for control over several towns and villages near the mountain, especially Šabac. On 19 August, the morale of the Austro-Hungarians collapsed and thousands of soldiers retreated into Austria-Hungary with many of them drowning in the Drina River as they fled in panic. On 24 August the Serbs re-entered Šabac, marking the end of the battle.

Serbian casualties after nearly ten days of fighting were 3,000–5,000 killed and 15,000 wounded. Those of the Austro-Hungarians were significantly higher, with 6,000–10,000 soldiers killed, 30,000 wounded and 4,500 taken as prisoners of war. The Serbian victory over the Austro-Hungarians marked the first Allied victory over the Central Powers in the First World War, and the first aerial dogfight of the war took place during the battle.