The McMahon-Hussein Correspondence between Hussein bin Ali, Sharif of Mecca and the British official Henry McMahon concerning the Arab Revolt against the Ottoman Empire begins.

The McMahon–Hussein Correspondence is a series of letters that were exchanged during World War I in which the Government of the United Kingdom agreed to recognize Arab independence after the war in exchange for the Sharif of Mecca launching the Arab Revolt against the Ottoman Empire. The correspondence had a significant influence on Middle Eastern history during and after the war; a dispute over Palestine continued thereafter.The correspondence is composed of ten letters that were exchanged from July 1915 to March 1916 between Hussein bin Ali, Sharif of Mecca and Lieutenant Colonel Sir Henry McMahon, British High Commissioner to Egypt. 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 to be "in the limits and boundaries proposed by the Sherif of Mecca" with the exception of "portions of Syria" lying to the west of "the districts of Damascus, Homs, Hama and Aleppo"; conflicting interpretations of this description were to cause great controversy in subsequent years. One particular dispute, which continues to the present, is the extent of the coastal exclusion.Following the publication of the November 1917 Balfour Declaration, which was a letter written by British Foreign Secretary Arthur James Balfour to Baron Rothschild, a wealthy and prominent leader in the British Jewish community, which promised a national home for the Jews in Palestine, and the subsequent leaking of the secret 1916 Sykes–Picot Agreement in which Britain and France proposed to split and occupy parts of the territory, the Sharif and other Arab leaders considered the agreements made in the McMahon–Hussein Correspondence had been violated. Hussein refused to ratify the 1919 Treaty of Versailles and in response to a 1921 British proposal to sign a treaty accepting the Mandate system stated that he could not be expected to "affix his name to a document assigning Palestine to the Zionists and Syria to foreigners". A further British attempt to reach a treaty failed in 1923–24 and negotiations were suspended in March 1924; within six months the British withdrew their support in favour of their central Arabian ally Ibn Saud, who proceeded to conquer Hussein's kingdom.The correspondence "haunted Anglo-Arab relations" for many decades thereafter. In January 1923 unofficial excerpts were published by Joseph N. M. Jeffries in the Daily Mail and copies of the letters circulated in the Arab press. Excerpts were published in the 1937 Peel Commission Report and the correspondence was published in full in George Antonius's 1938 book The Arab Awakening, then officially in 1939 as Cmd. 5957. In 1964 further documents were declassified.