During World War II the Lancaster was the most successful bomber used by the Royal Air Force. The Lanc had speed, ceiling and lifting power that no other aircraft could match. Generally flying under cover of darkness, the Lancaster had virtually no defensive armour and carried only eight .303 calibre machine guns for defence against enemy aircraft. Air gunners manned the rear and mid-upper turrets and the remainder of the crew consisted of a pilot, navigator, wireless operator, bomb aimer and flight engineer.

The Lancaster evolved from Britain's concern regarding the deteriorating international situation during the 1930's. The twin engined Avro Manchester was in the planning stages as the war began in 1939 and first flew in 1940. However it was plagued by instability and insufficient power. It's designer, Roy Chadwick, modified the Manchester by adding two engines and the result was the Lancaster which made it's first flight in January 1941. By war's end 7374 Lancasters had been built, 430 of them in Canada.

The Lancaster was Bomber Command's workhorse, carrying 84% of the tonnage dropped by the RAF during the war. A total of 3932 Lancasters were lost in action and 55,000 aircrew were killed while serving in them. Service in bombers was the most dangerous field in the allied military. In the words of Sir Arthur Harris, Chief of Bomber Command, "The Lancaster took the major part in winning the war, with it's attacks on Germany". Some further statistics: For every 100 aircrew, 51 were killed on ops, 9 were killed in crashes, 3 were seriously injured, 12 became POWs, 1 escaped capture and 24 survived unharmed.