 The founder of Yugoslavism, Croatian Bishop Josip Juraj Strossmayer advocated the unification of Croat lands into a Yugoslav monarchical federal state alongside other Yugoslavs.However, in spite of both Starčević's and Strossmayer's competing visions of identity, neither of their views had much influence beyond Croatia's intelligentsia.Croatian nationalism became a mass movement under the leadership of Stjepan Radić, leader of the Croatian People's Peasant Party after 1918 upon the creation of Yugoslavia.