["The British Journal of Sociology, EarlyView. ", "\nABSTRACT\nIn recent years, sociological interest in the study of social class—particularly its subjective dimensions—has intensified. This article contributes to this growing body of literature by focusing on Poland as a case within the Central and Eastern European region. It emphasizes the role of historical context and family histories in shaping processes of class mobility and class reproduction, and examines these processes from a biographical perspective. Drawing on a comparative analysis of biographical pathways of upward mobility and reproduction, we introduce two analytical concepts naming the historical moments/processes potentially reshaping individuals' class histories: openings, referring to moments that facilitate upward mobility, and ruptures, referring to interruptions in reproduction or obstacles to upward mobility. We also identify three pivotal historical moments that emerge in the collected narratives as shaping class histories and class identities in Poland: the Second World War, the 1989 political and educational transformation, and the integration into EU institutions from 2004 onwards. The analysis is based on 42 biographical interviews with academics. It demonstrates the value of qualitative, biographical methods for examining class identities, which often diverge from patterns captured by purely objective criteria. This approach further allows us to reveal the role of social history and multigenerational family history in making the individuals' class histories and identities complex and ambiguous.\n"]