By the end of the Second World War, the Group had grown to 15 squadrons. During the war, it included a significant proportion of Royal Australian Air Force (or Australian-born RAF) personnel, both aircrews and ground staff, who were concentrated in three "Article XV squadrons": No. 455 Squadron RAAF, No. 463 Squadron RAAF and No. 467 Squadron RAAF. The Group also famously included an elite, multi-national unit: No. 617 Squadron, perhaps better known as "The Dambusters". 617 Sqn was formed in March 1943, and comprised RAF, RAAF, RCAF/Canadian and RNZAF/New Zealand aircrew personnel, who had been hand-picked from squadrons throughout Bomber Command.