Mossad Le'aliyah Bet

The Mossad Le'aliyah Bet (Hebrew: 'המוסד לעלייה ב) (English, "The Institution for Immigration B") was a branch of the Jewish Defense Association (Haganah) in British Palestine that operated to facilitate Jewish immigration into the British Mandate of Palestine, in violation of unilateral British restrictions to Jewish immigration. It operated from 1938 until the founding of the State of Israel. The name's origin is a play on words: The Yishuv (Jewish Community in Palestine) referred to legal immigration as "Immigration A," and therefore called illegal immigration "Immigration B."

Even though the Mossad Le'aliyah Bet was officially founded on April 29, 1939, it had began operating during 1938. The reason for its establishment was the increasing limitation on legal Jewish immigration by the British Mandate authorities. The Mossad was founded on the basis of the Ha'apala movement. Its activity was initially centred in Athens and later on its centre moved to Paris.

In the first years after it was created, the Mossad achieved a certain measure of success. Operating primarily through the sea, in fifty cruises it was able to bring as many as 20,000 Jewish immigrants to Palestine. When World War II broke, the Mossad became virtually paralyzed and its activities were only renewed by August 1945.

Since that time and until the founding of Israel, the Mossad was able to bring an additional 64 ships with over 70,000 Jewish immigrants (many of whom were Holocaust survivors). In addition to the sea, although in a much smaller scale, the Mossad also brought immigrants via land, from the Arab world. Overall, the Mossad was able to bring about 100,000 Jews into what was to become the State of Israel.

The most famous ship used by the Mossad was Exodus which brought 4554 Holocaust survivors. Throughout most of its years, the Mossad was led by Shaul Avigur (Meirov). With the founding of Israel, the Mossad served as a basis for the agency Nativ (נתיב - "Path"), created in 1953 and also headed by Meirov, which brought Jews from Soviet block, Arab, and other countries.