Book excerpt: In History of the Jews in the Bohemian Lands, Martin Wein traces the interaction of Czechs and Jews, but also of Christian German-speakers, Slovaks, and other groups in the Bohemian lands and in Czechoslovakia throughout the first half of the twentieth century. This period saw accelerated nation-building and nation-cleansing in the context of hegemony exercised by a changing cast of great powers, namely Austria-Hungary, France, Nazi Germany, and the Soviet Union. The author examines Christian-Jewish and inner-Jewish relations in various periods and provinces, including in Subcarpathian Ruthenia, emphasizing interreligious alliances of Jews with Protestants, such as T. G. Masaryk, and political parties, for example a number of Social Democratic ones. The writings of Prague’s Czech-German-Jewish founders of theories of nationalism, Hans Kohn, Karl W. Deutsch, and Ernest Gellner, help to interpret this history.