Yugoslavia

Yugoslavia was a country in the western part of the Balkans during most of the 20th century. 

The Kingdom of Yugoslavia which before 3 October 1929 was known as the Kingdom of Serbs, Croats and Slovenes 

was established on 1 December 1918 by the union of the State of Slovenes, Croats and Serbs and the Kingdom of Serbia.

The Kingdom of Yugoslavia was invaded by the Axis powers in 1941, and because of the events that followed, was officially abolished in 1943 and 1945.

On 31 January 1946, the new constitution of Federal People's Republic of Yugoslavia, modeled after the Soviet Union, established six republics, an autonomous province, and an autonomous district that were part of SR Serbia. The federal capital was Belgrade. 

1. Socialist republic of Bosnia and Herzegovina, with capital in Sarajevo,
2. Socialist republic of Croatia, with capital in Zagreb,
3. Socialist republic of Macedonia, with capital in Skopje,
4. Socialist republic of Montenegro, with capital in Titograd,
5. Socialist republic of Serbia, with capital in Belgrade, which also contained:
   5a. Socialist autonomous province of Kosovo, with capital in Priština
   5b. Socialist autonomous province of Vojvodina, with capital in Novi Sad
6. Socialist republic of Slovenia, with capital in Ljubljana.