Clement Richard Attlee was a British politician who served as the Prime Minister of the United Kingdom from 1945 to 1951. He was a member of the Labour Party and is best known for his leadership during the post-World War II period, overseeing the implementation of significant social and economic reforms, including the establishment of the National Health Service and the nationalization of key industries. Attlee's government also played a key role in the decolonization of the British Empire. He is widely regarded as one of the most influential and successful British Prime Ministers of the 20th century.