Employing new research from both German and French sources, the author examines the role that the French Atlantic ports played for the Kriegsmarine during the Second World War. When the Wehrmacht overran France in May and June of 1940, the German Navy's dream of access to the Atlantic was realized, and Brest, Lorient, St Nazaire, La Pallice and Bordeaux were converted into naval bases for surface, U-boat and auxiliary cruiser operations, though it is only the heavily fortified U-boat bunkers that have received any attention to date. The book describes the extent to which the French, both locally and at the level of the Vichy Government, cooperated with the German authorities in occupied France to convert the existing ports, and explains how the 45,000 workers of the Todt Organisation built the monumental bunkers and other facilities. This fascinating narrative of the German occupation is balanced by the story of the vicious British maritime-air campaign that was commenced immediately following the fall of France, and which was far more effective than has been previously suggested. The German attempt to turn Brittany into a vast bastion area after the Normandy landings is a further aspect which is covered in detail for the first time. A highly readable account with many previously unpublished images.