The port of Brest was a convenient Atlantic base for the largest German warships, and as a consequence was frequently bombed by the RAF. It had been attacked when the Admiral Hipper was in dock during January and February and was once again a high priority target:
On the night of the 30th/31st March, a total of 134 bombers was despatched, the principal target being the Scharnhorst and Gneisenau at Brest, where 118 tons of H.E. were dropped. Results were difficult to observe on account of darkness and intense searchlight concentration, but reports indicate that a large proportion of the bombs were dropped on that area of the docks in which these battle cruisers were situated.
A number of aircraft saw the cruisers by the light of flares, and other aircraft report having straddled the target in all directions. Thirteen Wellingtons attacked Calais, starting a number of fires.
From the Air Situation Report for the week.