This map is part of a series of 19 animated maps showing the history of Europe and nations, 1918-1942.
It was decided to bring the Slavs of Southern Europe together into a single country because they had common ethnic and linguistic origins. However, there was considerable divergence on religious grounds: the majority of the Bosnian population was Muslim, while Croats and Slovenians were mostly Catholics, and Montenegro and Serbia were bastions of Orthodox Christianity.
After the war, the Kingdom of Serbs, Croats and Slovenians took the form of a parliamentary monarchy ruled by Alexander I. However, this new state was very unstable and the coexistence of a variety of nationalities led to difficulties. Because of the important role played by Serbia in the creation of the new kingdom, Serbian parties dominated the political process. This provoked the Croats into resistance and rejection of the constitution until 1925.
As it was not possible to obtain a consensus on the political organization of the kingdom, Alexander I decided to set up a dictatorship in 1929 and sought to impose the idea of a single Yugoslav nation which negated the concept of national diversity. The country was renamed “the Kingdom of Yugoslavia”.