In 1941, during the Second World War, 125,00 Canadians in uniform are in Great Britain as part of the Allied cause. Joining the military already in England, the 3rd Canadian Division in the largest convoy sailing from Canada, protected by protected by Royal Canadian Navy (RCN) corvettes and destroyers, has reached British shores. In intense training, the Canadian Active Force conducts joint artillery and infantry exercises that will ready the force for an offensive role overseas. Working with British regulars and militia, Canadian troops learn to use new weapons, such as the "Tommy gun".