Battle of Cer (August 16 - August 19, 1914)
The Battle of Cer, also known as the Jadar Battle was fought between Austria-Hungary and Serbia on the mountain of Cer in western Serbia. It went into history as the first Allied victory in World War I and one of the most important battles in Serbian history as it prevented the Austro-Hungarian attempt to invade Serbia.
The Austro-Hungarian army numbering 200,000 well equipped soldiers commanded by Field Marshal Oskar Potiorek invaded Serbia from northern Bosnia on August 12, 1914. The Serbian General Staff and its Chief Radomir Putnik knew about the Austro-Hungarian preparations for invasion but they were surprised by the location because they expected an attack from the north. When they realized that Potiorek was leading the main attack, the Second Army under the command of General Stepa Stepanović rushed to the mountain of Cer to help the Third Army commanded by Pavle Jurišić Šturm.
In the Battle of Cer that was fought from August 16 to August 19, the outnumbered and relatively poorly equipped Serbian Second and Third Armies (together numbering 180,000 men) decisively defeated the Austro-Hungarian troops and forced them to retreat from Serbia by August 24. The Serbian army lost about 16,000 men, while the Austro-Hungarians suffered about 23,000 casualties of whom about 4,500 were captured.