 Later, he was assigned to one of the horse remount depots on the Western Front.Munnings's talent was employed as a war artist to the Canadian Cavalry Brigade, under the patronage of Max Aitken, in the latter part of the war.During the war he painted many scenes, including in 1918 a portrait of General Jack Seely mounted on his horse Warrior (now in the collection of the National Gallery of Canada, Ottawa).