The countries occupying the Balkan peninsula of south-eastern Europe, lying south of the Danube and Sava rivers, between the Adriatic and Ionian seas in the west, the Aegean and Black seas in the east, and the Mediterranean in the south. It is the home of various peoples including Albanians, Vlachs, Greeks, Serbs, Bulgars, and Turks. From the 3rd to 7th century the Balkan peninsula, nominally ruled by the Byzantine emperors, was invaded by successive migrations of Slavs; later, parts of it were conquered by Venice and other states. In 1356 the Ottoman invasion began. Constantinople fell to the Turks in 1453, and by 1478 most of the peninsula was in their power; the subject nations, though largely retaining their languages and religions, did not recover independence until the 19th century. In 1912–13 Turkey was attacked and defeated by other Balkan peoples in alliance, then the former allies fought over their gains. After World War I the peninsula was divided between Greece, Albania, Bulgaria, and Yugoslavia, with Turkey retaining only Constantinople and the surrounding land. The area was in turmoil from 1991 to 1995 as Yugoslavia disintegrated into its constituent republics and a savage ethnic conflict developed in Bosnia and Herzegovina.