Thirteen days after the death of Queen Victoria, on 4 February 1901, the Royal Navy laid down its first submarine. His Majesty's Submarine No 1 was launched on 2 October of that same year. The early years proved difficult for the embryonic service because their lordships at the Admiralty failed to grasp the significance and potential of their new type of vessel. Common sense eventually prevailed and the submarine service went on to fight heroically through two World Wars and has now become the carrier of Britain's greatest defence weapon - the nuclear deterrent. This is the story of the evolution of the Royal Navy's submarines throughout the last 100 years. Each class is illustrated and described in detail. This volume shows the transition of the type from that of a submersible gunship, designed to fight with guns on the surface, to killer subs seeking out targets and launching torpedoes from beneath the surface. Today's lethal nuclear vessels can hide and roam in the world's oceans for months at a time. The technical development that has taken place in a century is remarkable. This book has been written with the help of the Royal Navy's Submarine Museum at Gosport, the Imperial War Museum and the various manufacturers of Royal Navy submarines.