Winston Churchill famously remarked that the threat of the German U-Boats was the only thing that had “really frightened” him during World War Two. The U-Boats certainly claimed a bitter harvest among Allied shipping: nearly 3,000 ships were sunk, for a total tonnage of over 14 million tonnes, nearly 70% of Allied shipping losses in all theatres of the war. With justification, then, they are an integral part of the traditional narrative of the Battle of the Atlantic; a story of technological brilliance, dramatic sinkings, life and death, and – of course – the sinister, unseen threat of the U-Boats themselves.

For Allied seamen during the war, the U-Boat was a hidden menace, a faceless killer lurking beneath the waves; and the urgent needs of survival afforded them little time or energy to consider the challenges and privations of their enemy. History, however, affords us that time and energy, and any pretence of comprehensiveness demands that we consider what life was like for the crews of those most claustrophobic vessels; packed into a steel hull, at the mercy of the enemy, of the elements – and of basic physics.

Germany’s U-Boat crews posted the highest per-capita losses of any combat arm during World War Two. Some 30,000 German submariners were killed – over 75% of the total number deployed – the vast majority of whom have no grave except the seabed. Using archival sources, unpublished diaries and existing memoir literature, this book will give the U-Boatmen back their voice, allowing their side of the narrative to be aired in a comprehensive manner for the first time.

With that testimony, Wolfpack takes the reader from the heady early days of the war, when U-Boat crews were buoyed with optimism about their cause, through to the challenges of meeting the Allied counterthreat, to the final horror of defeat, when their submarines were captured by the enemy or scuttled in ignominy. Using the U-Boatmen’s own voices to punctuate an engaging narrative, it tells their story; of courage, certainly, but also of fear, privation and – ultimately – failure.