Yugoslavia was a country in Southeast Europe that existed from 1918 to 2003. It was initially formed after World War I as the Kingdom of Serbs, Croats, and Slovenes, and later renamed the Kingdom of Yugoslavia. After World War II, it became a socialist federation known as the Socialist Federal Republic of Yugoslavia, consisting of six republics: Bosnia and Herzegovina, Croatia, Macedonia, Montenegro, Serbia, and Slovenia. In the 1990s, Yugoslavia faced political and ethnic tensions, leading to the breakup of the country. It eventually dissolved into several independent nations, including Bosnia and Herzegovina, Croatia, Macedonia, Montenegro, Serbia, and Slovenia.