Alijah bet, that is illegal immigration of Jews to Palestine, the mandate territory of Great Britain, constituted a Jewish reaction to the policy of the British authorities which by supporting the Arabs, had gradually gone back on the promises made to the Jews in the Balfour Declaration of 1917 and had limited the possibilities of their emigration to the mandate. Alijah bet was unofficially supported by many countries, including the Polish authorities, which looked upon the Jewish emigration as a way of solving Poland’s internal social and political problems. Poland’s aid to the Jewish migrants was clandestine and it took on various forms and shapes; for instance, the authorities made it possible for the Jews to leave as “tourists.” The “tourist emigration,” as it was referred to, had lasted throughout the entire inter-war period, but it had become particularly intense in the thirties. The action was supported both by travel agencies and by various Jewish organizations. The “tourist emigration” was directed not only toward Palestine, but also toward other countries. The Consular Department of the Ministry of Foreign Affairs estimated that in the year 1938 around 4 thousand “tourist migrants” had left for Palestine, whereas in the first quarter of 1939 a further 6 thousand had departed from Poland; this meant that among the total number of illegal migrants, the number of Jewish citizens from Poland constituted a very large percentage of new arrivals. However the activities of the Polish authorities required caution as alijah bet was directed against the state with which Poland was linked by a military alliance and whose aid was very much counted upon, in the event of a war with Germany.