Bomber Command comprised a number of Groups. It began the war with Nos. 1, 2, 3, 4 and 5 Groups. No. 1 Group was soon sent to France and then returned to Bomber Command control after the evacuation of France. No. 2 Group consisted of light and medium bombers who, although operating both by day and night, remained part of Bomber Command until 1943, when it was removed to the control of Second Tactical Air Force, to form the light bomber component of that command. Bomber Command also gained two new groups during the war: the Royal Canadian Air Force (RCAF) squadrons were organised into No. 6 Group and the Pathfinder Force was expanded to form No. 8 (Pathfinder) Group from existing squadrons.