This unique volume in the U-boat Aces series features the three German naval captains--Karl-Heinz Moehle, Reinhard Hardegen, and Horst von Schroeter--who commanded the U-123, a type IXB U-boat. In 12 patrols and 720 days at sea during its four-year WWII combat career, U-123 sank an incredible 44 Allied merchant and warships, ranking it with the third-most U-boat sinkings. Moehle, the first commander of U-123, successfully conducted three patrols in the North Atlantic and was awarded the Knight's Cross. Hardegen sank the first ship in US waters and was eventually awarded the Oak Leaves to his Knight's Cross. Schroeter, appointed U-123's commander in June 1942, also received the Knight's Cross after four combat patrols. All 12 of U-123's combat patrols are discussed in detail, as well as its participation in the wartime propaganda film U-boats Westward! The featured rare photography comes from the German U-boat Archive in Cuxhaven, as well as from former crew members.