Third Army
3rd Army WW1.svg
3rd Army formation badge.
Country United Kingdom
Branch British Army
TypeField army
EngagementsBattle of the Somme
Battle of Arras
Battle of Cambrai
Battle of Passchendaele
Battle of Amiens
Hundred Days Offensive
Edmund Allenby
Sir Julian Byng

The Third Army was a field army of the British Army during World War I that saw active service on the Western Front throughout the war.

First World War

The Third Army was part of the British Army during World War I and was formed in France on 13 July 1915, under the command of Lieutenant-General Charles Monro.[1]

During August 1915 the Third Army took over trench line south of the French Tenth Army, which had to keep in position for the forthcoming autumn offensive. This made the Third Army geographically separate from the other British Armies for the time being.[2] This remained the case until March 1916, when the French Tenth Army was redeployed because of French losses at Verdun and the British Fourth Army was formed in preparation for the Battle of the Somme.[3]

The battles it took part in on the Western Front included:

Order of battle

Third Army Order of Battle, August 1918.[5]



  1. ^ "The British Armies of 1914-1918 - The Long, Long Trail". Retrieved 10 September 2016.
  2. ^ Holmes 2004, p294
  3. ^ Robson, Stuart (2007). The First World War (1 ed.). Harrow, England: Pearson Longman. p. 62. ISBN 978-1-4058-2471-2 – via Archive Foundation.((cite book)): CS1 maint: date and year (link)
  4. ^ Burton, Pierre, Marching as to war, 2001, Toronto
  5. ^ Harper, Glyn, 1958- (2007). Dark journey. Auckland [N.Z.]: HarperCollins Publishers. p. 525. ISBN 9781869505790. OCLC 174060842.((cite book)): CS1 maint: multiple names: authors list (link)