1 April 1916 Major-General Claud Jacob 22 May 1916 Major-General David Campbell See also List of British divisions in World War I References Bibliography External links The British Army in the Great War: The 21st Division 21st division 1914–18 21st Infantry Division on the Western Front 1914–1918: A Case Study in Tactical Evolution, Kathryn Snowden (2001) Infantry divisions of the British Army in World War I Kitchener's Army divisions Military units and formations established in 1914 Military units and formations disestablished in 1919 1914 establishments in the United Kingdom