Balkan Wars

The First Balkan War began on 8 October 1912, when Montenegro declared war on the Ottoman Empire, followed within a week by Bulgaria, Serbia and Greece acting together as the Balkan League, and the four allied states rapidly stripped the Ottomans of nearly all their remaining European territory, with Bulgarian forces advancing to the outskirts of Constantinople itself before the Treaty of London ended the war on 30 May 1913 and established an independent Albania. The victorious allies almost immediately fell out over the division of captured Macedonian territory, and on 16 June 1913 Bulgaria attacked its former partners Serbia and Greece, beginning the Second Balkan War; Romania and the Ottoman Empire then joined against an isolated Bulgaria, which was defeated within two months and forced by the Treaty of Bucharest of August 1913 to cede territory and accept Serbian and Greek gains in Macedonia. The wars exposed the Ottoman Empire's continuing military decline while dramatically enlarging Serbia and emboldening its ambitions for South Slavic unification, a shift that sharply raised tensions with neighboring Austria-Hungary and is widely regarded by historians as one of the immediate preconditions for the outbreak of the First World War the following year.