When World War II began, Somerville volunteered his services. He distinguished himself working on the development of radar and then as Vice Admiral Bertram Ramsay's subordinate during the Dunkerque evacuation. After the fall of France, the Royal Navy established a covering force at Gibraltar with Somerville in command. In Operation catapult, Somerville negotiated with French Admiral Marcel Gensoul in an attempt to neutralize French naval units at Mers-el-Kébir. His Force H launched successive attacks on Oran and Dakar with aircraft and gunfire. The Ark Royal's aircraft then struck Italian bases at Genoa, Livorno, and on Sardinia and Sicily, and Force H covered multiple convoys to Malta from August 1940 to March 1942. Force H fought in the Battle of Cape Teulada on 26 November 1940 and played a decisive role in the hunting down of the German battleship Bismarck in May 1941.
In March 1942, Somerville took command of the Eastern Fleet, conducting holding operations against the Japanese First Air Fleet's Indian Ocean offensive. His carriers covered the Diégo-Suarez and Madagascar operations in May and September 1942 before withdrawing to serve elsewhere. Somerville's Eastern Fleet carriers recommenced offensive operations in 1944 until he relinquished command in August. He was reinstated an admiral on the active list after five years' war service at sea.
Somerville went to Washington in October to head the British naval delegation. He became admiral of the fleet in May 1945 and retired permanently the next year. Somerville died at Wells, Somerset, on 19 May 1949.
Paul E. Fontenoy
Brown, J. David. Carrier Operations in World War II: The Royal Navy. London: Ian Allan, 1968.; Greene, Jack, and Alessandro Massignani. The Naval War in the Mediterranean, 1940–1943. London: Chatham Publishing, 1998.; Macintyre, Donald. Fighting Admiral: The Life and Battles of Admiral of the Fleet Sir James Somerville. London: Evans Brothers, 1961.; Roskill, Stephen. The War at Sea, 1939–1945. 3 vols. London: Her Majesty's Stationery Office, 1954–1961.; Simpson, Michael. The Somerville Papers. Aldershot, UK: Naval Records Society, 1995.