Yugoslavia (Serbo-Croatian, Macedonian, Slovene: Jugoslavija, ???????????), once spelled and called "Jugoslavia", was a country in Southeast Europe during most of the 20th century. It came into existence after World War I in 1918[i] under the name of Kingdom of Serbs, Croats and Slovenes by the merger of the provisional State of Slovenes, Croats and Serbs (itself formed from territories of the former Austro-Hungarian Empire) with the formerly independent Kingdom of Serbia and Kingdom of Montenegro. The Serbian royal House of Kara?or?evi? became the Yugoslav royal dynasty. Yugoslavia gained international recognition on 13 July 1922 at the Conference of Ambassadors in Paris. The country was named after the South Slavic peoples and constituted their first union, following centuries in which the territories had been part of the Ottoman Empire and Austria-Hungary.

Renamed Kingdom of Yugoslavia on 3 October 1929, it was invaded by the Axis powers on 6 April 1941. In 1943, a Democratic Federal Yugoslavia was proclaimed by the Partisan resistance. In 1944, the king recognised it as the legitimate government, but in November 1945 the monarchy was abolished. Yugoslavia was renamed the Federal People's Republic of Yugoslavia in 1946, when a communist government was established. It acquired the territories of Istria, Rijeka, and Zadar from Italy. Leader of the Partisans Josip Broz Tito ruled the country as the president until his death in 1980. In 1963, the country was renamed again to the Socialist Federal Republic of Yugoslavia (SFRY).

The constituent six Socialist Republics that made up the country were SR Bosnia and Herzegovina, SR Croatia, SR Macedonia, SR Montenegro, SR Slovenia, and SR Serbia. Serbia contained two Socialist Autonomous Provinces: Vojvodina and Kosovo, which after 1974 were largely equal to the other members of the federation. After an economic and political crisis in the 1980s and the rise of nationalism, Yugoslavia broke up along its republics' borders, at first into five countries, leading to the Yugoslav Wars.

After the breakup, the republics of Serbia and Montenegro formed a reduced federation, the Federal Republic of Yugoslavia (FRY), which aspired to the status of sole legal successor to the SFRY, but those claims were opposed by the other former republics. Eventually, Serbia and Montenegro accepted the opinion of the Badinter Arbitration Committee about shared succession. Serbia and Montenegro themselves broke up in 2006 and became independent states, while Kosovo proclaimed independence in 2008.