When the first Lancaster heavy bombers were produced in Britain, the head of Bomber Command, Air Marshal Sir Arthur Harris, assigned them to the Royal Air Force (RAF). He decided that the Royal Canadian Air Force (RCAF) would be equipped with Canadian-manufactured Lancaster bombers when they became available.
On 9 September 1943, the first Canadian Lancaster rolled off the assembly line at the Victory Aircraft Limited factory in Toronto. Throughout the fall of 1943, pilots of the Atlantic Ferry Organization (AFTERO) flew a steady stream of Lancasters to the main RCAF base in Yorkshire, northern England. By 31 December 1943, the squadrons of RCAF Bomber Group 6 were flying Lancasters on nightly bombing raids against targets in Germany.