Montenegro is a country in Southeastern Europe. It has a coast on the Adriatic Sea to the south-west and is bordered by Croatia to the west, Bosnia and Herzegovina to the northwest, Serbia to the northeast, Kosovo to the east and Albania to the south-east. Its capital and largest city is Podgorica, while Cetinje is designated as the Prijestonica, meaning the former Royal Capital City. In the 10th century, there existed three Slavic principalities on the territory of Montenegro: Duklja, roughly corresponding to the southern half, Travunia, the west, and Rascia, the north. In 1042, archon Stefan Vojislav led a revolt that resulted in the independence of Duklja and the establishment of the Vojislavljević dynasty. Duklja reached its zenith under Vojislav's son, Mihailo (1046–81), and his son Bodin (1081–1101). By the 13th century, Zeta had replaced Duklja when referring to the realm. In the late 14th century, southern Montenegro came under the rule of the Balšić noble family, then the Crnojević noble family, and by the 15th century, Zeta was more often referred to as Crna Gora. As the Crnojević dynasty disintegrated, Montenegro was ruled by its Bishops until 1696, and then by the House of Petrović-Njegoš until 1918. From 1918, it was a part of Yugoslavia. On the basis of an independence referendum held on 21 May 2006, Montenegro declared independence on 3 June of that year. Montenegro is classified by the World Bank as a middle-income country. Montenegro is a member of the UN, the World Trade Organization, the Organization for Security and Co-operation in Europe, the Council of Europe, the Central European Free Trade Agreement and a founding member of the Union for the Mediterranean. Montenegro is currently an official candidate for membership in the European Union and official candidate for membership of NATO.