Clement Richard Attlee was a British politician who was the Prime Minister of the United Kingdom from 1945 to 1951 and the Leader of the Labour Party from 1935 to 1955. Attlee was the first person to hold the office of Deputy Prime Minister of the United Kingdom, serving under Winston Churchill in the wartime coalition government, before going on to lead the Labour Party to a landslide election victory in 1945 and a narrow victory in 1950. He became the first Labour Prime Minister ever to serve a full five-year term, as well as the first to command a Labour majority in Parliament and remains the longest-ever serving Leader of the Labour Party.