This insightful illustrated study investigates how the Royal Navy lost two battleships and three aircraft carriers to German U-boats during 1939–42. During World War II, over half of Britain's capital ship losses were due to U-boats, as Germany's submarines sought to deplete the Royal Navy's powerful surface fleet. Featuring specially commissioned artwork and mapping alongside archive photographs, this study explains how Germany's submarines sank five of Britain's major surface vessels in four years of conflict at sea. Aircraft carrier HMS Courageous was sunk by U-29 on 17 September 1939 during anti-submarine patrols. On 14 October 1939, U-47 penetrated the Scapa Flow defences and sank battleship HMS Royal Oak . On 14 November 1941, U-81 sank HMS Ark Royal as the aircraft carrier returned to Gibraltar. On 25 November 1941, U-331 sank HMS Barham off Egypt. The final British capital ship to be sunk by German submarines was carrier HMS Eagle , torpedoed by U-73 en route to Malta on 11 August 1942. In this book, Mark Lardas charts the origins, development and combat performance of the U-boats in the Kriegsmarine's efforts to attack British capital ships, and the Royal Navy's efforts to counter the submarine threat to its battleships, battlecruisers and aircraft carriers. As well as the five encounters that led to sinkings, he examines the 'near-misses' that saw Royal Navy capital ships get the better of the U-boats.