Formation of Yugoslavia 1918–20

Representatives of the southern Slavs had conferred in exile about the creation of a united post-World War I kingdom. As the Austro-Hungarian Empire fell apart, they convened a national council in Zagreb in 1918, but differences of view rapidly emerged. Both Croatia-Slavonia and Montenegro hankered after independence, fearing domination by Serbia (the sole pre-existing independent state, and on the victorious side in the war). However, both Dalmatia and Bosnia quickly allied with Serbia and Croatia-Slavonia, fearing punitive territorial claims from Italy, quickly caved in. The Kingdom of Croats, Slovenes and Serbs (KCSS) was born. Going into the Treaty of Versailles, KCSS had two key advantages; their troops were in possession of the territory they claimed and US President Woodrow Wilson was a fervent advocate of self-determination. At Versailles, and under four ensuing treaties, KCSS acquired Vojvodina, Prekomurje and Medjimurje from Hungary and four border enclaves from Bulgaria. However, at Rapallo, it ceded Zara and Lagosta to Italy.