Acknowledgments; List of abbreviations and Russian terms; Introduction: the Communist Party in Leninist theory, Soviet practice and historical scholarship; 1. Building a workers' party; 2. Which way to socialism? NEP and the struggle for power; 3. Laying the foundations: the rank-and-file and rapid industrialisation; 4. Marxism and clean canteens: cultural activism between ideology and practice; 5. Democratisation and repression; 6. Party activism on the road to war; 7. Conclusion: the vanguard concept as a promising category for historical research; Bibliography.