This book explores the radicalization and fascistization of the Ustasa-The Croatian Revolutionary Organization within the interwar Kingdom of Serbs, Croats and Slovenes and later Yugoslavia, whose tumultuous rise led to terrorism and racial cleansing throughout the western Balkans.Using an interdisciplinary and socio-cultural approach, Constantin Iordachi and Goran Miljan trace the Ustasa's political trajectory from its ideological and organizational roots in the 1920s, to its guerrilla struggle and terrorist activities in the 1930s, to its genocidal rule, violent downfall, and post-1945 metamorphosis in exile. By considering the paramount role played by prejudice, economic deprivation, and the breakdown of social institutions in fueling grievances against an existing socio-political system, the authors place the emergence of the Ustasa in the context of the interwar Kingdom of Yugoslavia but also in the wider perspective of the emergence of fascist movements and regimes in interwar and wartime Europe.