He was Prime Minister of Great Britain from 1957 until 1963
[DOC] [TLE] BBC ON THIS DAY | 10 | 1957: Macmillan becomes Prime Minister [PAR] Born in 1894 to an American mother and British father, Harold Macmillan served 
in ... Harold Macmillan served as prime minister until 1963 when he resigned due 
to ... His greatest achievement came in 1963 when he was heavily involved in... [DOC] [TLE] A Slice of Time: The MacMillan Cabinet - Great Britain Since 1945 ... [PAR] Jul 14, 2016 ... Prime Minister Macmillan on the cover of Time ... Macmillan was the 
Conservative Party Prime Minister from January 1957 until mid-October 1963.