The Division was the first of the six created for the Third New Army on 13 September 1914. It moved to France in September 1915. It took part in the Battle of Loos in September 1915, the Battle of the Somme in autumn 1916, the Battle of Arras in April 1917, the Battle of Passchendaele in autumn 1917 and the Battle of Cambrai in November 1917.[1] The division suffered 55,581 killed, wounded and missing, being the highest number of casualties suffered by any New Army division.[1] The Division ceased to exist on 19 May 1919.[2]
In July 1916 the brigade joined from the 37th Division, swapping with the 63rd Brigade. Brigadier-General (temporary) Edward Loch took command on 22 July 1917.
V.21 Heavy Trench Mortar Battery R.F.A. (joined 1 June 1916, left February 1918)
W.21 Medium Mortar Battery R.F.A. (joined May, left August 1916)
X.21, Y.21 and Z.21 Medium Mortar Batteries R.F.A. 4 x 6-inch mortars each (joined 1–13 March 1916; in February 1918, Z broken up and batteries reorganised to have 6 x 6-inch mortars each)
Becke, Major A.F. (1938). Order of Battle of Divisions Part 3A. New Army Divisions (9–26). London: His Majesty's Stationery Office. ISBN1-871167-08-6.
Further reading
Clayton, Derek (2023). To Do the Work of Men: An Operational History of the 21st Division in the Great War. Wolverhampton Military Studies. Warwick: Helion. ISBN978-1-80451-233-3.