スロベニア人・クロアチア人・セルビア人国
On December 1, 1918, Serbia united with the newly created State of Slovenes, Croats and Serbs to form a new southern Slav state, the Kingdom of Serbs, Croats and Slovenes. The new country continued to be ruled by the Serbian monarchy when in August 1921 Prince Alexandar I became king.