This important new reference work details all those ships and vessels of the Royal Navy, large and small, which were lost by accident or enemy action, during the twentieth century, from the end of the First World War, to the last years of the century. In all, the fates of over 2,000 ships and small craft are covered, from aircraft carriers and battleships to motor launches, harbour tenders and tugs. Those vessels hired or purchased for wartime service, such as trawlers, paddle steamers and yachts are also listed. During wartime ships are lost; it is their purpose to go in harm's way. Hostile gunfire, torpedoes and mines were established threats throughout the period, while the increasing threat of air attack and the introduction of weapons employing new technology, such as influence-triggered mines, homing torpedoes or air-launched guided weapons added to the risks of operating in a hostile environment. Ships operating in extremely hazardous conditions, such as at Dunkirk in 1940 or Singapore in 1942, suffered heavy losses in brief, concentrated conflicts; but the long continuous campaigns, such as the Atlantic convoys or the constant need to sweep for mines also took their toll. Peacetime losses are dominated by submarine casualties, demonstrating the dangerous character of that service. To this may be added the hazardous nature of the sea itself, when ships are lost in heavy weather; sometimes, human error or plain foolishness may play a part. The core of the book is taken up by those losses experienced during the Second World War, but peacetime losses and more recent conflicts such as the Falklands War of 1982 are included. Arranged chronologically, every entry notes the outline details of the vessel, identifies the Commanding Officer, where known, and gives a full and often harrowing account of the circumstances of the loss and the number of casualties. The details come from extensive original research using primary source material wherever possible, particularly the relevant War Diaries and the collected loss and damage reports, casualty reports and reports of proceedings, now in the National Archives. Wartime losses of the Dominions are included, to ensure completeness. This comprehensive record of warship losses, from all causes, suffered by the Royal Navy over the past one hundred years, is the first single-volume work on the subject and represents a major milestone in naval research and publishing.