During World War II the regiment was among the first Canadian units to see combat in the European theatre during the invasion of Dieppe. By the end of The Dieppe Raid, the Essex Scottish Regiment had suffered 121 fatal casualties, with many others wounded and captured. The Essex Scottish later participated in Operation Atlantic and was slaughtered attempting to take Verrières Ridge on July 21. By the war's end, the Essex Scottish Regiment had suffered over 550 war dead; its 2,500 casualties were the most of any unit in the Canadian army during the Second World War.