This dissertation examines the process of re-establishment of Jewish communities in two cities: in Wroclaw, a city that passed after 1945 from Germany to Poland, and in L’viv, a city that passed from Poland to Soviet Ukraine. This process was thus overseen by two different Communist regimes. The dissertation compares the similarities and differences in the policies of the two regimes. The attempt to re-establish Jewish life largely failed and the dissertation explains why the effort to create communities that were self-identified as Jewish yet loyal to the Communist state did not succeed. The first chapter looks at the prewar history and wartime destruction of the Jewish communities in Breslau in Germany and in Lwów in Poland. The dissertation then goes on to trace the efforts of the postwar regimes, supported by those Jews who had survived the Holocaust and who chose not to leave Eastern Europe, to reconstitute Jewish life. It examines the history of these communities up to 1968 in the case of Wroclaw and up to the 1970s in the case of L’viv. The comparison is explored in relation to five inter- related contexts. The primary context is that of the official policies towards Jews of the government of the Polish People’s Republic and of the government of the Ukrainian Soviet Socialist Republic. Chapters 2, 3 and 4 examine the aims and effects of these official policies, highlighting the many similarities in the policies between the two regimes. The second context of enquiry is directly related to the first and concerns how central policies were implemented at the local level. The contexts relating to official policy and its local implementation intersect with a third context, namely, that which relates less to Communist ideology and policy and more to the particular national contexts of Poland and Soviet Ukraine. The fourth context explores both popular and official antisemitism and how this shaped the fate of the postwar Jewish communities in Wroclaw and L’viv. The fifth context is how the economic and social modernization that the Communist regimes carried out affected the development of the Jewish communities.