The Irgun joined forces with Hatzohar and Betar in September 1937, when it assisted with the landing of a convoy of 54 Betar members at Tantura Beach (near Haifa.) The Irgun was responsible for discreetly bringing the Olim, or Jewish immigrants, to the beaches, and dispersing them among the various Jewish settlements. The Irgun also began participating in the organisation of the immigration enterprise and undertook the process of accompanying the ships. This began with the ship "Draga" which arrived at the coast of British Palestine in September 1938. In August of the same year, an agreement was made between Ari Jabotinsky (the son of Ze'ev Jabotinsky), the Betar representative and Hillel Kook, the Irgun representative, to coordinate the immigration (also known as Ha'apala). This agreement was also made in the "Paris Convention" in February 1939, at which Ze'ev Jabotinsky and David Raziel were present. Afterwards, the "Aliyah Center" was founded, made up of representatives of Hatzohar, Betar, and the Irgun, thereby making the Irgun a full participant in the process.