The engagement with communism shaped the history of the Federal Republic of Germany. German communism experienced an unprecedented renaissance not only in the Soviet zone but also in West Germany after the Nazi repressions in the early post-war years. This work examines, from a regional historical perspective, the development of communism in the Federal Republic beyond a narrow party-historical viewpoint for the first time. Based on a broad approach that connects political, social, and cultural historical aspects, it situates the rise and fall of the communist movement within the history of German society between Nazi dictatorship and democratic stabilization. In addition to an analysis of the inner workings of the communist community of conviction, it explores the concept of total socialization.