Clement Richard Attlee, 1st Earl Attlee, KG, OM, CH, PC, FRS (3 January 1883 – 8 October 1967) is a British politician who serves as the Prime Minister of the United Kingdom from 1945 to 1951, and as the Leader of the Labour Party from 1935 to 1955.

He is the first person ever 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 becomes the first Labour Prime Minister ever to serve a full term, as well as the first to command a Labour majority in Parliament, and remains to date the longest-ever serving Leader of the Labour Party.

First elected to Parliament in 1922 as the MP for Limehouse, he rises quickly to become a minister in the minority government led by Ramsay MacDonald in 1924.

In 1931, after the Labour Party had suffered a disastrous election defeat, he is elected Deputy Leader of the Labour Party.

Four years later, he becomes the Leader of the Labour Party after the resignation of George Lansbury.

After reversing Labour's previous policy of pacificism and appeasement, he becomes a fierce critic of Neville Chamberlain's attempts to appease Adolf Hitler.

He takes Labour into the wartime coalition government, 1939-45 formed by Winston Churchill.

Initially serving as the Lord Privy Seal, he is appointed Deputy Prime Minister two years later.

With victory assured in the Second World War in 1945, the coalition government is dissolved and Attlee leads Labour to win a huge majority in the ensuing general election.

The government he leads builds the postwar consensus, based upon the assumption that full employment would be maintained by Keynesian policies and that a greatly enlarged system of social services would be created – aspirations that had been outlined in the wartime Beveridge Report.

Within this context, his government undertakes the nationalization of public utilities and major industries, as well as the creation of the National Health Service.

After initial Conservative opposition to Keynesian fiscal policy, this settlement is broadly accepted by all parties for over three decades until Margaret Thatcher becomes Prime Minister in 1979.

His government also presided over the decolonization of a large part of the British Empire, granting British India, Burma, and Ceylon independence, as well as ending the British Mandate of Palestine and the British Mandate of Jordan.

When the budget crisis forces Britain out of Greece in 1947, he encourages the United States to counter the Soviets with the Truman Doctrine.

He avidly supports the Marshall Plan to rebuild Western Europe with American money, and the NATO military alliance against the Soviet bloc.

After leading Labour to a narrow victory in 1950, he is narrowly defeated by Churchill in 1951; he retires from politics in 1955.

In public, Attlee appears modest and unassuming; he is ineffective at public relations and lacks charisma.

His strengths emerge behind the scenes, especially in committees where his depth of knowledge, quiet demeanor, objectivity and pragmatism prove decisive.

He sees himself as spokesman on behalf of the entire party, and successfully keeps its multiple factions in harness.

His reputation among scholars in recent decades has been much higher than during his years as Prime Minister, thanks to his role in forging the welfare state and opposing the Soviet Union in the Cold War.

In 2004 he was voted the greatest British Prime Minister of the 20th Century by a poll of 139 academics organized by Ipsos MORI.