The paper traces the development of Soviet studies on ancient slavery from their beginnings after the October Revolution until Perestroika in the 1980s. It shows how these studies, while closely dependent on the political directives of the Marxist-Leninist authorities, slowly moved from initial sociological generalizations to specialised research. Further development was however hampered by an orthodoxy which became ever more rigid, notwithstanding efforts of some historians to create more space for debate. The contribution ends with a retrospective from a post-Soviet point of view, mustering the results and reflecting on the standstill already before Perestroika. A postscript addresses the works of the Soviet ancient historian M.E. Sergeenko, illustrating the possibility of doing research without Marxism, neither opposing nor embracing it.