Examining the history of Soviet museums in the 1920s and 1930s, this book engages with the core problem of interwar museology: adequately representing the historical development of art to create a plausible and coherent version of its evolution. The book critically analyzes the evolution of museology and art history during a period recognized as a crisis point for museums, characterized by the ascent of the modernist museum and the decline of previous museum representation forms such as universal collections and period rooms. Building on the concept of museums as agents of cultural diplomacy and soft power, the book considers museums as spaces where negotiations, often unsuccessful occur among various stakeholders: museum practitioners, authorities, private collectors, auction houses, and the public. The challenge of handling millions of nationalized objects since the 1917 Revolution posed a particularly complex issue for Socialist museums, necessitating accumulation, distribution, and display. It also proposes a historical account of the establishment of Soviet art departments in the mid-1930s, serving as showcases for Socialist realism. This composition was subsequently replicated across the country and throughout the Communist bloc. This book is ideal reading for researchers in History of Art, Museum Studies, Soviet Studies, Eastern European Studies and 20th Century History.