
Reunited for the first time in a single corps under the command of Canadian Lieutenant-General Julian Byng, the four Canadian divisions meticulously prepared their assault on the ridge. The sappers dug twelve tunnels at least 10 metres deep, perpendicular to the enemy lines, to bring the fighters as close as possible to them. In the rear, German lines were reconstituted to train their men. Their gunners had been shelling enemy positions since mid-March and underground mines exploded in no-man’s-land on the morning of April 9. The Canadians launched the assault at the same time as the British in front of Arras. Within half an hour, the Canadian Corps had taken the first German line. The next day, it had complete control of the ridge.