Country, former substate of Serbia and Montenegro and former kingdom in SE Europe that originated after the Battle of Kosovo in 1389, when the Serbs were forced to retreat into the Black Mountain area. It borders Croatia to the W, Bosnia and Herzegovina to the NW, Serbia to the NE, and Albania to the SE. Sporadic warfare with the Turks lasted, however, until the 19th century. Ruled by prince-bishops after 1515, Montenegro never accepted Turkish authority. Danilo I (1696–1735) made the episcopal succession hereditary in the Niegosh family and began alliances with Russia. Under Peter I (1782–1830) Montenegro fought beside Russia in its wars against Turkey and in 1799 gained recognition from Sultan Selim III as an independent kingdom. Peter also began reforms that were continued by Peter II (1830–51). Under Nicholas I (1910–18) Montenegro gained both formal recognition as an independent state by the Congress of Berlin in 1878, and territory that included a small outlet on the Adriatic Sea. Proclaiming himself king in 1910, Nicholas was involved in the Balkan Wars and declared war on Austria-Hungary in 1914 in displeasure over its annexation of Bosnia and Herzegovina. The country was overrun by Austro-German forces in 1915 as World War I progressed. A national assembly in 1918 deposed Nicholas and joined with Serbia, thus creating a kingdom of Serbs, Croats, and Slovenes. In 1946 Montenegro became one of the six republics of Yugoslavia, with its capital at Titograd (now Podgorica). In 1992 Montenegro federated with Serbia as Serbia and Montenegro. After a referendum in 2006, Montenegro declared independence and became the 192nd member state of the United Nations.