Sir Winston Leonard Spencer-Churchill, KG, OM, CH, TD, PC, FRS (30 November 1874 – 24 January 1965) was a British politician known chiefly for his leadership of the United Kingdom during World War II. He served as Prime Minister from 1940 to 1945 and again from 1951 to 1955. First Lord of the Admiralty during World War I; Prime Minister during World War II.