"Royal Air Force Bomber Command, 1939-1941." A Boeing Fortress Mark I of No. 90 Squadron RAF, taking off from Polebrook, Northamptonshire, to attack the German battlecruiser GNEISENAU docked at Brest, France. Three of the Squadron's Fortresses accompanied the attacking force, bombing the vessel from 30,000 feet in an effort to draw enemy fighters from the other bombers.