Aliyah Bet (Hebrew: עלייה ב'‎, "Aliyah 'B'" – bet being the second letter of the Hebrew alphabet) was the code name given to illegal immigration by Jews, most of whom were refugees escaping from Nazi Germany, and later Holocaust survivors, to Mandatory Palestine between 1920 and 1948, in violation of the restrictions laid out in the British White Paper of 1939, which dramatically increased between 1939 and 1948.With the establishment of the State of Israel in May 1948, Jewish displaced persons and refugees from Europe began streaming into the new sovereign state.