Cunningham was the best-known and most celebrated British admiral of the Second World War. He held one of the two major fleet commands between 1939 and 1942, and in 1942-43, he was Allied naval commander for the great amphibious operations in the Mediterranean. From 1943 to 1946, he was the First Sea Lord and a participant in the wartime conferences with Churchill, Stalin, Roosevelt and the US Chiefs of Staff, deliberating the global strategy for Allied victory. He also led a very active public life for almost 20 years after his retirement in 1946. Cunningham's papers are abundant for the period 1939-63 and are supplemented here by Cabinet and Admiralty records, papers of his service contemporaries and of Churchill, and by memories of his family and friends, as well as extensive US archives and private papers. This book is more frankly critical than other studies of Cunningham have been, emphasising the Anglo-American basis of his activities from spring 1942 to spring 1946 and devoting attention to his performance as First Sea Lord. The overriding aim of is to place Cunningham's life and career within the global strategic context, the shifting position of Britain in the world power stakes, and the political, economic, diplomatic, inter-service and technological constraints on sea power, as well as the limitations imposed by the distinctive culture and command structure of the Royal Navy in the first half of the twentieth century. This biography will be essential reading for all students of Second World War naval history and for practising professionals in the field, as well as being of much interest to general readers of military history.