This chapter charts the development of Pan-south Slavism as a utopian ideal that formed the basis of the first (prewar) Yugoslavia, the Kingdom of Serbs, Croats, and Slovenes. The analysis centers on two prominent representations of utopia—a Serbian and a Croatian example, representatives of the two largest national groups—in Yugoslav culture from the interwar period: Ljubomir Micić’s avant-garde Zenithist movement and Miroslav Krleža’s expressionist writings. The tension between the national and the supranational, which determines Yugoslav Pan-Slavism, is expressed in their works through a tension between ideas for individual (Serbian and Croatian) nationality and Yugoslavism, and in their use of the trope of the (failed) national hero—the Barbaric Genius who attempts but does not manage to bring about a new utopian age.