On May 15th, 1941, the Palmach, the special operations unit of the Haganah, was established. The Palmach, or “Pelugot Hamahatz,” meaning “strike force,” was formed due to concerns about the Nazi invasion of British Mandatory Palestine during World War II. The Palmach consisted of six companies deployed to strategic locations throughout Mandatory Palestine. During World War II, the Palmach cooperated with British forces and received funding, supplies, and training in skills like hand-to-hand combat and mobile fighting. Many fighters from the Palmach units were deployed to Europe on missions to save Jews from concentration and death camps. At the end of World War II, many Jewish youth immigrated to Eretz Yisrael and joined the Palmach. In response, the Palmach added three additional units and developed a stronger structure to accommodate its growing ranks. In 1945, as the British continued to limit Jewish immigration to the Mandate, the Palmach began to run missions against them and managed to land over 60 ships worth of Holocaust survivors on the beaches of Mandatory Palestine and settle them in Eretz Yisrael. As the conflict continued, it became clear that the British were preparing to cede control of Mandatory Palestine. Tensions escalated between the Arab population of the region, the neighboring Arab countries, and the Yishuv (the Jews living in Palestine), each of which wanted to be able to fill the incoming vacuum of power. At this time, both the Palmach and Haganah transitioned toward the defense of the local Jewish population. In 1948, the Arab countries rejected the United Nations partition plan and invaded. Israel declared itself to be an independent country, and fighting ramped up into what is now known as the War of Independence. The Palmach soon merged with the Haganah and Irgun to create the Israel Defense Forces (IDF). There were about 2,200 fighters and 900 reservists deployed to regions around Israel in order to help hold back the advancing Arab armies coming in from Egypt, Syria, Lebanon, Transjordan, Iraq, and Yemen. During the War of Independence, the Palmach captured Haifa and Jaffa and is credited with the liberation of the Upper Galilee, in addition to helping open the roads to allow Jewish forces to reach Jerusalem. After the war, the Palmach was fully integrated into the IDF, and a number of new special forces units were established under the direction of Prime Minister David Ben-Gurion.