 Complete the following phrase:  The nation of Yugoslavia was created in the aftermath of World War I, and it was mostly composed of South Slavic Christians, though the nation also had a substantial Muslim minority. Clear ethnic conflict between the Yugoslav peoples only became prominent in the 20th century, beginning with tensions over the constitution of the Kingdom of Serbs, Croats, and Slovenes in the early 1920s and escalating into violence between Serbs and Croats in the late 1920s after the assassination of Croatian politician Stjepan Radić. This nation lasted from 1918 to 1941, when it was 