The battle at St. Eloi between 27 March and 19 April 1916 was a minor side-show compared to the armageddon raging between the Germans and the French at Verdun. Yet, it was an important event for the 2nd Canadian Division as it was their first set-piece battle on the Western Front. It was also an unmitigated disaster.
Cook, Tim "The Blind Leading the Blind: The Battle of the St. Eloi Craters." Canadian Military History 5, 2 (1996)