The Mandate system was instituted by the League of Nations in the early 20th century to administer non-self-governing territories. The mandatory power, appointed by an international body, was to consider the mandated territory a temporary trust and to see to the well-being and advancement of its population.
In July 1922, the League of Nations entrusted Great Britain with the Mandate for Palestine. Recognizing "the historical connection of the Jewish people with Palestine," Great Britain was called upon to facilitate the establishment of a Jewish national home in Palestine-Eretz Israel (Land of Israel). Shortly afterwards, in September 1922, the League of Nations and Great Britain decided that the provisions for setting up a Jewish national home would not apply to the area east of the Jordan River, which constituted three-fourths of the territory included in the Mandate and which eventually became the Hashemite Kingdom of Jordan.
The British Mandate authorities granted the Jewish and Arab communities the right to run their internal affairs; thus the yishuv established the Elected Assembly and the National Council. The economy expanded, a Hebrew education network was organized and cultural life flourished.
The Mandatory government did not succeed in maintaining the letter and spirit of the Mandate. Under Arab pressure, it withdrew from its commitment, especially with respect to immigration and land acquisition. The White Papers of 1930 and 1939 restricted immigration and acquisition of land by Jews. Later, immigration was limited by the 1930 and 1939 White Papers, and land acquisition by Jews was severely restricted by the 1940 Land Transfer Regulations.
After the UN General Assembly adopted the resolution to partition Palestine on November 29, 1947, Britain announced the termination of its Mandate over Palestine, to take effect on May 15, 1948. On May 14, 1948, the State of Israel was proclaimed.
Sources: Israeli Foreign Ministry