Muhammad Asad (1900-1992) and Hugo Hamid Marcus (1880-1966) were two Central European Jews who converted to Islam in interwar Berlin. While conversion to Islam does not rank among the hallmarks of modern European-Jewish history, I argue that the case of these two converts is inextricable from, and reflective of, the broader social and cultural dynamics that defined Jewish identity in the early twentieth-century. My talk examines how Asad and Marcus articulated their views of Islam and forged their Muslim identities in relation to their Jewish backgrounds. My central question is how these two figures drew on the dilemmas of modern Jewish selfhood in order to think about the challenges of Muslim identity, tradition and culture in the geographical contexts they lived in and travelled to. On a broader level, this lecture explores the transformations that religious identities undergo in the process of modernization and migration, and investigates the central role that conversion plays in the transmission and circulation of religious beliefs and narratives across cultures.