information:extraction
Kingdom of Yugoslavia

The Corfu Declaration was a formal agreement between the government-in-exile of the Kingdom of Serbia and the Yugoslav Committee (anti-Habsburg South Slav émigrés) that pledged to unify Kingdom of Serbia and Kingdom of Montenegro with Austria-Hungary's South Slav autonomous crown lands: Kingdom of Croatia-Slavonia, Kingdom of Dalmatia, Slovenia, Vojvodina (then part of the Kingdom of Hungary) and Bosnia and Herzegovina in a post-war Yugoslav state. It was signed on 20 July 1917 on Corfu.

As the Austro-Hungarian Empire collapsed, the territory of Syrmia united with Serbia on 24 November 1918. Just a day later, the Great People's Assembly of Serbs, Bunjevci and other Slavs in Banat, Bačka and Baranja declared the unification of these regions (Banat, Bačka, and Baranja) with Serbia.

On 26 November 1918, the Podgorica Assembly deposed the House of Petrović-Njegoš and united Montenegro with Serbia. On 1 December 1918, in Belgrade, Serbian Prince Regent Alexander Karađorđević proclaimed the Kingdom of the Serbs, Croats, and Slovenes, under King Peter I of Serbia. King Peter was succeeded by his son, Alexander, in August 1921. Serb centralists and Croat autonomists clashed in the parliament, and most governments were fragile and short-lived. Nikola Pašić, a conservative prime minister, headed or dominated most governments until his death. King Alexander established a dictatorship in 1929 with the aim of establishing the Yugoslav ideology and single Yugoslav nation, changed the name of the country to Yugoslavia. The effect of Alexander's dictatorship was to further alienate the non-Serbs living in Yugoslavia from the idea of unity.

Alexander was assassinated in Marseille, during an official visit in 1934 by Vlado Chernozemski, member of the IMRO. Alexander was succeeded by his eleven-year-old son Peter II. In August 1939 the Cvetković–Maček Agreement established an autonomous Banate of Croatia as a solution to Croatian concerns.