The Serbo-Bulgarian War or the Serbian–Bulgarian War, a war between the Kingdom of Serbia and the Principality of Bulgaria, erupted on 14 November [O.S. 2 November] 1885 and lasted until 28 November [O.S. 16 November] 1885. Despite Bulgaria's status as a vassal of the Ottoman Empire, the Ottomans did not intervene in the war. Serbia initiated the fighting but suffered a decisive defeat. Austria-Hungary demanded that Bulgaria stop its invasion, and a truce resulted.