German attack on Vimy Ridge, 21 May 1916
In 1932, Edmonds recorded 1,344 German casualties; 615 men in the attack and 729 during British counter-attacks. British casualties in the 47th Division from 22 to 24 May were 1,571, 2nd Division casualties were 267 and the 7th Brigade (25th Division) had 637 casualties, a total of 2,475. In 1936, the official historians of "Der Weltkrieg", the German official history, recorded that 300 British prisoners had been taken.
Battle of Vimy Ridge
Trench raiding involved making small-scale surprise attacks on enemy positions, often in the middle of the night for reasons of stealth. All belligerents employed trench raiding as a tactic to harass their enemy and gain intelligence. In the Canadian Corps trench raiding developed into a training and leadership-building mechanism. The size of a raid would normally be anything from a few men to an entire company, or more, depending on the size of the mission. The four months before the April attack saw the Canadian Corps execute no fewer than 55 separate trench raids. Competition between units even developed with units competing for the honour of the greatest number of prisoners captured or most destruction wrought. The policy of aggressive trench raiding was not without its cost. A large-scale trench raid on 13 February 1917, involving 900 men from the 4th Canadian Division, resulted in 150 casualties. An even more ambitious trench raid, using chlorine gas, on 1 March 1917, once again by the 4th Canadian Division, failed and resulted in 637 casualties including two battalion commanders and a number of company commanders killed. This experience did not lessen the extent to which the Canadian Corps employed trench raiding with raids being conducted nightly between 20 March and the opening of the offensive on 9 April, resulting in approximately 1,400 additional Canadian casualties. The Germans operated an active patrolling policy and although not as large and ambitious as those of the Canadian Corps, they also engaged in trench raiding. As an example, a German trench raid launched by 79 men against the 3rd Canadian Division on 15 March 1917 was successful in capturing prisoners and causing damage.