What is the "Mandate for Palestine"? And what was "Palestine"?
What is the "Mandate for Palestine"? And what was "Palestine"?

The “Mandate for Palestine,” an historical League of Nations document, laid down the Jewish legal right to settle anywhere in western Palestine, a 10,000-square-mile area between the Jordan River and the Mediterranean Sea, an entitlement unaltered in international law and valid to this day.

The legally binding document was conferred on April 24, 1920, at the San Remo Conference, and its terms outlined in the Treaty of Sèvres on August 10, 1920. The Mandate’s terms were finalized and unanimously approved on July 24, 1922, by the Council of the League of Nations, which was comprised at that time of 51 countries.

The Mandate weathered the test of time: On April 18, 1946, when the League of Nations was dissolved and its assets and duties transferred to the United Nations, the international community, in essence, reaffirmed the validity of this international accord and reconfirmed that the terms for a Jewish national home were the will of the international community, a “sacred trust.”

Some may confuse the “Mandate for Palestine” [The Trust], with the British Mandate [The Trustee]. The “Mandate for Palestine” laid down the Jewish legal rights in Palestine. The British Mandate, on the other hand, was entrusted by the League of Nations with the responsibility to administer the area delineated by the “Mandate for Palestine.”  

The name "Palestine" was the name given by the Romans to the area when they conquered Judea and tried to erase the memory of Jewish independence; it is a geographic name, not a national one, and during the Ottoman Empire period and the ensuing British Mandate, those living in it were Palestinian Jews and Palestinian Arabs.

Great Britain, the Mandatory and Trustee, turned over its responsibility to the United Nations, as of May 14, 1948. However, the legal force of the League of Nations i.e. the “Mandate for Palestine” was not terminated with the end of the British Mandate. Rather, the Trust was transferred over to its successor – the United Nations.

British Mandate for Palestine
British Mandate for PalestineINN: EH

Map source: Delineating the final geographical area of Palestine designated for the Jewish National Home as described by the Mandatory: “Report by the Majesty’s Government in the United Kingdom of Great Britain and Northern Ireland to the Council of the League of Nations on the Administration of Palestine and Trans-Jordan for the year 1938.”