21st Division (United Kingdom)


The 21st Division was an infantry division of the British Army during World War I, raised in September 1914 by men volunteering for Lord Kitchener's New Armies. The division moved to France in September 1915 and served on the Western Front for the duration of the First World War.
The division's insignia was the "triple-seven".

Unit history

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. The division suffered 55,581 killed, wounded and missing, being the highest number of casualties suffered by any New Army division. The Division ceased to exist on 19 May 1919.

Order of battle

The following units served with the division:
62nd Brigade
63rd Brigade
In July 1916 the brigade moved to the 37th Division, swapping with the 110th Brigade.
  • 8th Battalion, Lincolnshire Regiment
  • 8th Battalion, Prince Albert's
  • 12th Battalion, Prince of Wales's Own
  • 4th Battalion, Duke of Cambridge's Own
  • 10th Battalion, York and Lancaster Regiment
  • 63rd Machine Gun Company
  • 63rd Trench Mortar Battery
64th Brigade
110th Brigade
In July 1916 the brigade joined from the 37th Division, swapping with the 63rd Brigade.
  • 6th Battalion, Leicestershire Regiment
  • 7th Battalion, Leicestershire Regiment
  • 8th Battalion, Leicestershire Regiment
  • 9th Battalion, Leicestershire Regiment
  • 1st Battalion, Duke of Edinburgh's
  • 110th Machine Gun Company
  • 110th Trench Mortar Battery
Divisional Troops
Royal Artillery
  • XCIV Brigade, Royal Field Artillery
  • XCV Brigade, R.F.A.
  • XCVI Brigade, R.F.A.
  • XCVII Brigade, R.F.A
  • 21st Divisional Ammunition Column R.F.A.
  • 21st Heavy Battery, Royal Garrison Artillery
  • V.21 Heavy Trench Mortar Battery R.F.A.
  • W.21 Medium Mortar Battery R.F.A.
  • X.21, Y.21 and Z.21 Medium Mortar Batteries R.F.A. 4 x 6-inch mortars each
Royal Engineers
  • 85th Field Company
  • 86th Field Company
  • 97th Field Company
  • 98th Field Company
  • 126th Field Company
  • 21st Divisional Signals Company
Royal Army Medical Corps
  • 63rd Field Ambulance
  • 64th Field Ambulance
  • 65th Field Ambulance
  • 38th Sanitary Section

    Commanders

During its existence, 21st Division had the following commanders: