Much of the literature on the Jews of the Maghreb imagines a singular Jewish community associated to the countries in which Jews lived in the 20th century. These identities, defined as "Tunisian Jews," "Algerian Jews," and "Moroccan Jews," were produced by the creation of national boundaries under colonial rule and the development of national institutions that encompassed the Jewish community of each country. Yet these "fixed" identities conceal a more complicated reality, which was characterized by fluid identities that were contingent of circumstance, migration across political boundaries in the Maghreb and larger Mediterranean world, and the strategic marketplace of citizenship. The different timing of colonialism in the Maghreb in the 19th and 20th centuries, and the distinctive status granted to the Jews by the colonial regimes in Algeria, Tunisia, and Morocco, contributing to a complicated web of relations across the political frontiers. Seeking commercial opportunities, the acquisition of citizenship, or religious training, Jews would migrate across the countries of the Maghreb, or elsewhere in the Mediterranean: Gibraltar, Livorno, Marseilles, etc. Algerian Jews, with their French citizenship might find opportunities in Morocco, while Moroccan rabbis could obtain leadership positions in local Algerian communities. New or developing towns, under the colonial economy, were frequently composed of Jewish migrants from across the boundaries, from Libya to Tunisia or between Eastern Morocco and Western Algeria for example. In examining these diverse migratory patterns, I argue that national identities were much more contingent and ambiguous than is often thought.