World War I: Beginning of the Battle of Cer, the first Allied victory of World War I.

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 Allies or the Entente was an international military coalition of countries led by the French Republic, the United Kingdom, the Russian Empire, the United States, the Kingdom of Italy, and the Empire of Japan against the Central Powers of the German Empire, Austria-Hungary, the Ottoman Empire, and the Kingdom of Bulgaria in World War I (1914–1918).