The Battle of Kolubara, was fought between Austria-Hungary and Serbia in November and December 1914, during which campaign of World War I was fought from late July 1914, when Austria-Hungary invaded the Kingdom of Serbia at the outset of World War I, until the war's conclusion in November 1918?
Serbian Campaign of World War I The Serbian Campaign of World War I was fought from late July 1914, when Austria-Hungary invaded the Kingdom of Serbia at the outset of World War I, until the war's conclusion in November 1918. The front ranged from the Danube River to southern Macedonia and back north again, and it drew in forces from almost all the combatants of the war.
Bosnian crisis The Bosnian crisis of 1908–09, also known as the Annexation crisis or the First Balkan Crisis, erupted when on 8 October 1908, Austria-Hungary announced the annexation of Bosnia and Herzegovina, territories formally within the sovereignty of the Ottoman Empire. This unilateral action—timed to coincide with Bulgaria's declaration of independence (5 October) from the Ottoman Empire—sparked protestations from all the Great Powers and Austria-Hungary's Balkan neighbours, Serbia and Montenegro. In April 1909 the Treaty of Berlin was amended to reflect the "fait accompli" and bring the crisis to an end. The crisis permanently damaged relations between Austria-Hungary on one hand and Serbia, Italy and the Russian Empire on the other. The Italian historian Luigi Albertini regarded it as laying the grounds for World War I. Although the crisis ended with what appeared to be a total Austro-Hungarian diplomatic victory, Russia became determined not to back down again and hastened its military build-up. Austrian–Serbian relations became permanently stressed.