Between 1941 and 1945, more than eight hundred shiploads of supplies were delivered to the Soviet Union protected by allied naval forces. Each journey was a battle against the elements, with turbulent seas, extreme cold, and the constant dread of torpedoes. These Arctic convoys have been mythologized as defenseless vessels at the mercy of deadly U-boats--but was this really the case?

David Kenyon explores the story of the war in the Arctic, revealing that the contest was more evenly balanced that previously thought. Battles included major ship engagements, aircraft carriers, and combat between surface ships. Amid this wide range of forces, Bletchley Park's Naval Section played a decisive role in Arctic operations, with both sides relying heavily on Signals Intelligence to intercept and break each other's codes. Kenyon presents a vivid picture of the Arctic theater of war, unearthing the full-scale campaign for naval supremacy in northern waters.