The occupation of Istanbul (1918) and İzmir (1919) by the Allies in the aftermath of World War I prompted the establishment of the Turkish National Movement. Under the leadership of Mustafa Kemal Pasha, a military commander who had distinguished himself during the Battle of Gallipoli, the Turkish War of Independence (1919–1923) was waged with the aim of revoking the terms of the Treaty of Sèvres (1920).