Consisting of men volunteering for Kitchener's Army, the brigade, after initially experiencing severe difficulties in training the men, due to a shortage of weapons and equipment, was sent to reinforce the British Expeditionary Force (BEF) on the Western Front in August 1915, later fighting, most notably, in the battles of the Somme, Messines and Passchendaele.

In June 1918 the brigade was awarded its only Victoria Cross (VC), belonging to Lieutenant-Colonel Charles Hudson of the Sherwood Foresters.

The brigade (now with the 1st Battalion, Tyneside Scottish in place of the 12th DLI, which was redesignated on 1 January 1940) arrived in France on 25 April 1940.

After serving in South Wales District and Western Command, the 70th Brigade was, on 18 May 1942, assigned to the 49th (West Riding) Infantry Division.

[4] The 49th Division, another TA formation, and composed of the 146th and 147th Infantry Brigades and supporting divisional troops, had also been serving in Iceland, where they gained the nickname of "The Polar Bears".

[6] The brigade, now commanded by Brigadier Percy Paulet King,[4] together with the rest of the 49th Division, spent the remaining two years in the United Kingdom, training for offensive action.

[8] The 70th Brigade then fought a bloody battle around Rauray as Kampfgruppe Weidinger of 2nd SS Panzer Division counterattacked between 29 June and 1 July.