In the paper, the author deals with the questions of Yugoslavism and the national homogenization in the nineteenth and twentieth centuries. He analyses the character of the Illyrian movement, the Croatian 'pravaštvo', Strossmayer's Yugoslav idea, the Yugoslav nationalist and political concepts by F. Supil and A. Trumbić and, especially, the Serbian ideas regarding the political association of the Southern Slavic nations in the nineteenth century. He also presents the Slovenian views on this question before 1918. He further deals with the nationalist questions during the time of the first two Yugoslav states. His main conclusion is that ever since the Yugoslav idea first occurred and throughout the existence of the Yugoslav state after 1918, the federalist and unitarianist concepts were in constant confrontation. The latter, in conjunction with the hegemonist Greater Serbian policy, eventually compelled the non-Serbian nations to abandon the Yugoslav state, thereby burying the idea of the association of Southern Slavic nations. Today, the Yugoslav idea is devoid of any living contents, and the only thing the present Federal Republic of Yugoslavia has in common with it, is its name.