 He considered himself a soldier first; his father was a military leader in Guelph and McCrae grew up believing in the duty of fighting for his country and empire.McCrae fought in the Second Battle of Ypres in the Flanders region of Belgium, where the German army launched one of the first chemical attacks in the history of war.They attacked French positions north of the Canadians with chlorine gas on April 22, 1915 but were unable to break through the Canadian line, which held for over two weeks.