The history of the Ottoman Empire during World War I began with the Ottoman engagement in the Middle Eastern theatre. There were several important Ottoman victories in the early years of the war, such as the Battle of Gallipoli and the Siege of Kut. The Arab Revolt which began in 1916 turned the tide against the Ottomans on the Middle Eastern front, where they initially seemed to have the upper hand during the first two years of the war. The Armistice of Mudros was signed on 30 October 1918, and set the partition of the Ottoman Empire under the terms of the Treaty of Sèvres. This treaty, as designed in the conference of London, allowed the Sultan to retain his position and title. The occupation of Constantinople and İzmir led to the establishment of a Turkish national movement, which won the Turkish War of Independence (1919–22) under the leadership of Mustafa Kemal (later given the surname "Atatürk"). The sultanate was abolished on 1 November 1922, and the last sultan, Mehmed VI (reigned 1918–22), left the country on 17 November 1922. The caliphate was abolished on 3 March 1924.