Libman and Obydenkova reveal how legacies of the Communist Party of the Soviet Union (CPSU) have survived in the politics, economic development, culture, and society of post-Communist regions in the 21st Century. The authors show how this impact is not driven by Communist ideology but by the clientelistic practices, opportunism and cynicism prevalent in the CPSU. Their study is built on a novel dataset of the CPSU membership rates in Russian regions in the 1950s-1980s, alongside case studies, interviews and an analysis of mass media previously only available in Russian and discussed here in English for the first time. It will appeal to students and scholars of Russian and Eastern European politics and history, and anyone who wants to better understand countries which live or have lived through Communism: from Eastern Europe to China and East Asian Communist states.