Sir Winston Leonard Spencer-Churchill was a British politician, army officer, and writer, who was Prime Minister of the United Kingdom from 1940 to 1945 and again from 1951 to 1955. As Prime Minister, Churchill led Britain to victory in the Second World War. Churchill represented five constituencies during his career as Member of Parliament. Ideologically an economic liberal and British imperialist, he began and ended his parliamentary career as a member of the Conservative Party, which he led from 1940 to 1955, but for twenty years from 1904 he was a prominent member of the Liberal Party.
Born in Oxfordshire to an aristocratic family, Churchill was a son of Lord Randolph Churchill and Jennie Jerome. Joining the British Army, he saw action in British India, the Anglo–Sudan War, and the Second Boer War, gaining fame as a war correspondent and writing books about his campaigns. Elected an MP in 1900, initially as a Conservative, he defected to the Liberals in 1904. In H. H. Asquith's Liberal government, Churchill served as President of the Board of Trade, Home Secretary, and First Lord of the Admiralty, championing prison reform and workers' social security.