When the German Battleship Bismarck was commissioned in 1940 she was one of the fastest and most powerful ships afloat. To the Royal Navy and the security of Allied shipping in the Atlantic she posed an enormous threat – she must be destroyed. When she broke out into the Atlantic in 1941 some of Britain’s most powerful ships were sent to pursue and sink her. The first encounter proved disastrous for the British Battleship HMS Hood which was sunk at 0800 on 24 May. Bismarck had sustained several hits from HMS Prince of Wales but the Royal Navy were unsure of the extent of the damage and whether she would attempt to return to Germany for major repairs or sail for France to lick her wounds. Previous written accounts suggest that the whereabouts and course of Bismarck were unknown to the Allies until discovered by an RAF Catalina at 1030 on 26 May. This was followed an hour later by the arrival of a Fairey Swordfish flying off HMS Ark Royal. This aircraft hit the Bismarck with her torpedo and severely damaged her steering gear. It was now only a matter of time before the full firepower of the British capital ships would close in and destroy Germany’s greatest ship. This new book revises previous theory of the events in which earlier publications have failed to reveal the full extent of the capabilities of both British and German Radar or the significance of British ULTRA signal intercepts.