During the Early Medieval period, three Serb principalities were located on the territory of modern-day Montenegro: Duklja, roughly corresponding to the southern half; Travunia, the west; and Rascia proper, the north. In 1042, archon Stefan Vojislav led a revolt that resulted in the independence of Duklja from the Byzantine Empire and the establishment of the Vojislavljević dynasty. The independent Principality of Zeta emerged in the 14th and 15th centuries, ruled by the House of Balšić between 1356 and 1421, and by the House of Crnojević between 1431 and 1498, when the name Montenegro started being used for the country. After falling under Ottoman rule, Montenegro regained de facto independence in 1697 under the rule of the House of Petrović-Njegoš, first under the theocratic rule of prince-bishops, before being transformed into a secular principality in 1852. Montenegro's de jure independence was recognised by the Great Powers at the Congress of Berlin in 1878, following the Montenegrin–Ottoman War. In 1905, the country became a kingdom. After World War I, it became part of Yugoslavia. Following the breakup of Yugoslavia, the republics of Serbia and Montenegro together established a federation known as the Federal Republic of Yugoslavia, which was renamed State Union of Serbia and Montenegro in 2003. On the basis of an independence referendum held in May 2006, Montenegro declared independence and the federation peacefully dissolved on 3 June of that year.
Since 1990, the sovereign state of Montenegro has been governed by the Democratic Party of Socialists and its minor coalition partners. Classified by the World Bank as an upper middle-income country, Montenegro is a member of the UN , NATO , the World Trade Organization , the Organization for Security and Co-operation in Europe , the Council of Europe , and the Central European Free Trade Agreement . It is a founding member of the Union for the Mediterranean .