Mandatory Palestine[a][1] (Arabic: فلسطين‎ Filasṭīn; Hebrew: פָּלֶשְׂתִּינָה (א"י) Pālēśtīnā (EY), where "EY" indicates "Eretz Yisrael", Land of Israel) was a geopolitical entity established between 1920 and 1923 in the region of Palestine as part of the Partition of the Ottoman Empire under the terms of the British Mandate for Palestine.

During the First World War (1914–18), an Arab uprising and the British Empire's Egyptian Expeditionary Force under General Edmund Allenby drove the Turks out of the Levant during the Sinai and Palestine Campaign.[2] The United Kingdom had agreed in the McMahon–Hussein Correspondence that it would honour Arab independence if they revolted against the Ottomans, but the two sides had different interpretations of this agreement, and in the end, the UK and France divided up the area under the Sykes–Picot Agreement—an act of betrayal in the eyes of the Arabs. Further complicating the issue was the Balfour Declaration of 1917, promising British support for a Jewish "national home" in Palestine. At the war's end the British and French set up a joint "Occupied Enemy Territory Administration" in what had been Ottoman Syria. The British achieved legitimacy for their continued control by obtaining a mandate from the League of Nations in June 1922. The formal objective of the League of Nations mandate system was to administer parts of the defunct Ottoman Empire, which had been in control of the Middle East since the 16th century, "until such time as they are able to stand alone."[3] The civil Mandate administration was formalised with the League of Nations' consent in 1923 under the British Mandate for Palestine, which covered two administrative areas.