Jews in Moravia, a mixed Czech- and German-speaking province of Habsburg Austria and later Czechoslovakia, spoke German and formed a part of the German community. Nevertheless, they always formed a separate German Jewish group within the community of Germans, and not because of antisemitism. Rather, the primary identity of Moravian Jews was as Jews who spoke German, not Germans who practiced Judaism. The settlement patterns of Jewish life sustained this German Jewish group and made German into a Jewish language. In interwar Czechoslovakia, which suspected Germans of disloyalty, Jews demonstrated their loyalty by declaring on the census that they belonged to the “Jewish nationality.” That they spoke German did not mean that they belonged to the German nation. Their easy switch to Czech in the mid-1930s, in response to the increased popularity of radical German nationalism, reveals the fluidity of national identities and the primacy of Jewish identity for the Jews of Moravia.