The sinking of the Cunard liner Laconia (built 1922 by Swan Hunter, Wallsend on Tyne and stationed at Liverpool) by a German U-boat in 1942 has become famous, not only because it was the second-worst Allied maritime disaster of the War but also because it was the last occasion in the history of the sea when a submarine tried to help its own victims. Nearly two thousand people lost their lives in the incident, but nearly a thousand were saved by the heroic efforts of the German submarine commander, Werner Hartenstein. This is an exhaustive general history of the incident and its broader historical significance. The Laconia was torpedoed and sunk by U-156 in the middle of the south Atlantic while carrying nearly three thousand people, including some 1800 Italian prisoners of war. There then followed one of the most remarkable events of the war: the U-Boat launched a major attempt to rescue survivors. The Germans sent three submarines to help. The Italians sent another. The French, under risk of Allied attack, sent three warships from Dakar. The British could do nothing, and the Americans, from a secret base on Ascension Island, sent a Liberator Bomber to attack the rescuing submarines. Afterwards, Admiral Donitz issued what has now become known as 'The Laconia Order': no attempts to pick up any survivors in further U-Boat attacks, making this the last incident in which a submarine tried to help its own victims. It is difficult to imagine an incident of equal importance which has been almost universally neglected by naval historians. This is the first examination of it by a British historian and the only previous book-length account was that by the French historian Peillard, in U-Boats to the Rescue , published as long ago as 1963 and leaving unanswered many questions such as the identity of the attacking aeroplane. This important book is lavishly illustrated and contains an appendix recording the names of all those known to have been lost.