premise: Harold Macmillan served as the first Prime Minister of the United Kingdom.
hypothesis: Maurice Harold Macmillan , 1st Earl of Stockton , ( 10 February 1894 -- 29 December 1986 ) was a British Conservative politician and statesman who served as the Prime Minister of the United Kingdom from 10 January 1957 to 19 October 1963 . Macmillan was the last British prime minister born in the reign of Queen Victoria , the last to have served in the First World War , the last to wear a moustache when in office , and the last to receive an hereditary peerage .