The Palmach (Hebrew: פלמ”ח‎, acronym for Plugot Maḥatz (Hebrew: פלוגות מחץ‎), “strike force”) was the elite fighting force of the Haganah, the underground army of the Yishuv (Jewish community) during the period of the British Mandate for Palestine. The Palmach was established on 15 May 1941. By the outbreak of the 1948 Arab–Israeli War it consisted of over 2,000 men and women in three fighting brigades and auxiliary aerial, naval and intelligence units. With the creation of Israel’s army, the three Palmach Brigades were disbanded. This and political reasons compelled many of the senior Palmach officers to resign in 1950.[1]

The Palmach contributed significantly to Israeli culture and ethos, well beyond its military contribution. Its members formed the backbone of the Israel Defense Forces high command for many years, and were prominent in Israeli politics, literature and culture.

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,[1][2][3] and later Holocaust survivors, to Mandatory Palestine between 1920 and 1948,[2] 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.

In modern-day Israel it has also been called by the Hebrew term Ha’apala (Hebrew: הַעְפָּלָה‎, “Ascension”). The Aliyah Bet is distinguished from the Aliyah Aleph (“Aliyah ‘A'”, Aleph being the first letter of the Hebrew alphabet) which refers to the limited Jewish immigration permitted by British authorities during the same period. The name Aliya B is also shortened name for Aliya Bilty Legalit (Hebrew: עלייה בלתי-לגאלית‎, “illegal immigration”).