The 73rd Brigade was originally raised during the First World War in September 1914 from men volunteering for Lord Kitchener's New Armies, and was assigned to the 24th Division. The brigade consisted of battalions from the East of England and spent the early months of its existence training. The brigade, with the division, departed for the Western Front in August 1915, fighting in many of the major battles of the war, such as the Battle of Loos, the Battle of the Somme, the Battle of Vimy Ridge, Battle of Passchendaele and in the German spring offensive and the Hundred Days Offensive, which saw the war come to an end on 11 November 1918 . The brigade had suffered extremely heavy casualties during the war and was disbanded in late March 1919.