Sir Winston Leonard Spencer Churchill KG OM CH TD DL FRS RA was a British statesman, military officer, and writer who was Prime Minister of the United Kingdom from 1940 to 1945 and again from 1951 to 1955. Apart from 1922 to 1924, he was a member of Parliament from 1900 to 1964 and represented a total of five constituencies. Ideologically an adherent to economic liberalism and imperialism, he was for most of his career a member of the Conservative Party, which he led from 1940 to 1955. He was a member of the Liberal Party from 1904 to 1924.
Of mixed English and American parentage, Churchill was born in Oxfordshire into the wealthy, aristocratic Spencer family. He joined the British Army in 1895 and saw action in British India, the Mahdist War and the Second Boer War, gaining fame as a war correspondent and writing books about his campaigns. Elected a Conservative MP in 1900, he defected to the Liberals in 1904. In H. H. Asquith's Liberal government, Churchill was president of the Board of Trade and Home Secretary, championing prison reform and workers' social security.