The Mandate for Palestine was a League of Nations mandate for British administration of the territories of Palestine and Transjordanwhich had been part of the Ottoman Empire for four centuriesfollowing the defeat of the Ottoman Empire in World War I. Under the mandate, Britain assumed obligations both to the inhabitants of Palestine and to the establishment of a Jewish national home, as set out in the British government's 1917 Balfour Declaration. The mandate was assigned to Britain by the San Remo conference in April 1920, after France's concession in the 1918 Clemenceau–Lloyd George Agreement of the previously agreed "international administration" of Palestine under the Sykes–Picot Agreement. Transjordan was added to the mandate after the Arab Kingdom in Damascus was toppled by the French in the Franco-Syrian War. Civil administration began in Palestine and Transjordan in July 1920 and April 1921, respectively, and the mandate was in force from 29 September 1923 to 15 May 1948 and to 25 May 1946 respectively.

The mandate document was based on Article 22 of the Covenant of the League of Nations of 28 June 1919 and the Supreme Council of the Principal Allied Powers' San Remo Resolution of 25 April 1920. The mandatory power's objective was to administer the territories as a trust until they were "able to stand alone", taking into account the wishes and interests of their inhabitants. However, it was not itself a sovereign authority over the territory, and could not unilaterally transfer sovereignty to itself or independently establish territorial title. The border between Palestine and Transjordan was agreed in the final mandate document, and the approximate northern border with the French Mandate for Syria and the Lebanon was agreed in the Paulet–Newcombe Agreement of 23 December 1920.

In Palestine, the Mandate required Britain to put into effect the Balfour Declaration's "national home for the Jewish people" without prejudicing the rights of the existing non-Jewish population living there; this requirement and others, however, would not apply to the separate Arab emirate to be established in Transjordan. The British controlled Palestine for almost three decades, overseeing a succession of protests, riots and revolts between the Jewish and Palestinian Arab communities. During the Mandate, the area saw the rise of two nationalist movements: Zionism among the Jews and Palestinian, Arab or Syrian nationalism among the Palestinian Arabs. Intercommunal conflict in Mandatory Palestine ultimately produced the 1936–1939 Arab revolt and the 1944–1948 Jewish insurgency. The United Nations Partition Plan for Palestine was passed on 29 November 1947; this envisaged the creation of separate Jewish and Arab states operating under economic union, and with Jerusalem transferred to UN trusteeship. The plan allocated a majority of the territory to the proposed Jewish state, despite Jewish inhabitants forming a minority of the population at the time. Two weeks later, British Colonial Secretary Arthur Creech Jones announced that the British Mandate would end on 15 May 1948. On the last day of the Mandate, the Jewish community there issued the Israeli Declaration of Independence. After the failure of the United Nations Partition Plan for Palestine, the 1948 Palestine war ended with Mandatory Palestine divided among Israel, the Jordanian annexation of the West Bank and the Egyptian All-Palestine Protectorate in the Gaza Strip.

Transjordan was added to the mandate following the Cairo Conference of March 1921, at which it was agreed that Abdullah bin Hussein would administer the territory under the auspices of the Palestine Mandate. Since the end of the war it had been administered from Damascus by a joint Arab-British military administration headed by Abdullah's younger brother Faisal, and then became a no man's land after the French defeated Faisal's army in July 1920 and the British initially chose to avoid a definite connection with Palestine. The addition of Transjordan was given legal form on 21 March 1921, when the British incorporated Article 25 into the Palestine Mandate. Article 25 was implemented via the 16 September 1922 Transjordan memorandum, which established a separate "Administration of Trans-Jordan" for the application of the Mandate under the general supervision of Great Britain. In April 1923, five months before the mandate came into force, Britain announced its intention to recognise an "independent Government" in Transjordan; this autonomy increased further under a 20 February 1928 treaty, and the state became fully independent with the Treaty of London of 22 March 1946.

Background

Commitment regarding the Arab population: the McMahon–Hussein correspondence

Between July 1915 and March 1916, a series of ten letters were exchanged between Sharif Hussein bin Ali, the head of the Hashemite family that had ruled the Hejaz as vassals for almost a millennium, and Lieutenant Colonel Sir Henry McMahon, British High Commissioner to Egypt. In the letters – particularly that of 24 October 1915 – the British government agreed to recognise Arab independence after the war in exchange for the Sharif of Mecca launching the Arab Revolt against the Ottoman Empire. Whilst there was some military value in the Arab manpower and local knowledge alongside the British Army, the primary reason for the arrangement was to counteract the Ottoman declaration of jihad ("holy war") against the Allies, and to maintain the support of the 70 million Muslims in British India (particularly those in the Indian Army that had been deployed in all major theatres of the wider war).

The area of Arab independence was defined as "in the limits and boundaries proposed by the Sherif of Mecca", with the exclusion of a coastal area lying to the west of "the districts of Damascus, Homs, Hama and Aleppo"; conflicting interpretations of this description caused great controversy in subsequent years. A particular dispute, which continues to the present, was whether Palestine was part of the coastal exclusion. At the Paris Peace Conference in 1919, British Prime Minister David Lloyd George told his French counterpart Georges Clemenceau and the other allies that the McMahon-Hussein correspondence was a treaty obligation.

Commitment to the French: the Sykes–Picot agreement

Around the same time, another secret treaty was negotiated between the United Kingdom and France (with assent by the Russian Empire and Italy) to define their mutually-agreed spheres of influence and control in an eventual partition of the Ottoman Empire. The primary negotiations leading to the agreement occurred between 23 November 1915 and 3 January 1916; on 3 January the British and French diplomats Mark Sykes and François Georges-Picot initialled an agreed memorandum. The agreement was ratified by their respective governments on 9 and 16 May 1916. The agreement allocated to Britain control of present-day southern Israel and Palestine, Jordan and southern Iraq, and an additional small area including the ports of Haifa and Acre to allow access to the Mediterranean. The Palestine region, with smaller boundaries than the later Mandatory Palestine, was to fall under an "international administration". The agreement was initially used as the basis for the 1918 Anglo–French Modus Vivendi, which provided a framework for the Occupied Enemy Territory Administration (OETA) in the Levant.

Commitment regarding the Jewish people: the Balfour Declaration

Immediately following their declaration of war on the Ottoman Empire in November 1914, the British War Cabinet began to consider the future of Palestine (at the time, an Ottoman region with a small minority Jewish population). By late 1917, in the lead-up to the Balfour Declaration, the wider war had reached a stalemate. Two of Britain's allies were not fully engaged, the United States had yet to suffer a casualty, and the Russians were in the midst of the October Revolution. A stalemate in southern Palestine was broken by the Battle of Beersheba on 31 October 1917. The release of the Balfour Declaration was authorised by 31 October; the preceding Cabinet discussion had mentioned perceived propaganda benefits amongst the worldwide Jewish community for the Allied war effort.

The British government issued the Declaration, a public statement announcing support for the establishment of a "national home for the Jewish people" in Palestine, on 2 November 1917. The opening words of the declaration represented the first public expression of support for Zionism by a major political power. The term "national home" had no precedent in international law, and was intentionally vague about whether a Jewish state was contemplated. The intended boundaries of Palestine were not specified, and the British government later confirmed that the words "in Palestine" meant that the Jewish national home was not intended to cover all of Palestine. The second half of the declaration was added to satisfy opponents of the policy, who said that it would otherwise prejudice the position of the local population of Palestine and encourage antisemitism worldwide by (according to the presidents of the Conjoint Committee, David L. Alexander and Claude Montefiore in a letter to the Times) "stamping the Jews as strangers in their native lands". The declaration called for safeguarding the civil and religious rights for the Palestinian Arabs, who composed the vast majority of the local population, and the rights of Jewish communities in any other country.

The Balfour Declaration was subsequently incorporated into the Mandate for Palestine to put the declaration into effect. Unlike the declaration itself, the Mandate was legally binding on the British government.

Commitment to the League of Nations: the mandate system

The mandate system was created in the wake of World War I as a compromise between Woodrow Wilson's ideal of self-determination, set out in his Fourteen Points speech of January 1918, and the European powers' desire for gains for their empires. It was established under Article 22 of the Covenant of the League of Nations, entered into on 28 June 1919 as Part I of the Treaty of Versailles, and came into force on 10 January 1920 with the rest of the treaty. Article 22 was written two months before the signing of the peace treaty, before it was agreed exactly which communities, peoples, or territories would be covered by the three types of mandate set out in sub-paragraphs 4, 5, and 6 – Class A "formerly belonging to the Turkish Empire", Class B "of Central Africa" and Class C "South-West Africa and certain of the South Pacific Islands". The treaty was signed and the peace conference adjourned before a formal decision was made.

Two governing principles formed the core of the mandate system: non-annexation of the territory and its administration as a "sacred trust of civilisation" to develop the territory for the benefit of its native people. The mandate system differed fundamentally from the protectorate system which preceded it, in that the mandatory power's obligations to the inhabitants of the territory were supervised by a third party: the League of Nations. The mandates were to act as legal instruments containing the internationally agreed-upon terms for administering certain post-World War I territories on behalf of the League of Nations. These were of the nature of a treaty and a constitution, which contained minority-rights clauses that provided for the rights of petition and adjudication by the World Court.