Records of Prime Ministers of the United Kingdom combined with his first term (13 July 176530 July 1766) his total time in office was 1 year and 113 days, which exceeds the total periods of several other Prime Ministers. (The Duke of Wellington had also served as Prime Minister between 1828 and 1830.) Consequently, the Prime Minister with the total shortest period in office was George Canning, whose sole term lasted 119 days from 12 April 1827 until his death on 8 August 1827. The Prime Minister with the longest period between the start of their first appointment and the end of their final term was the Duke
Historical rankings of Prime Ministers of the United Kingdom using a 0 to 10 scale, where 0 meant highly unsuccessful and 10 meant highly successful. Overall, MPs rated Margaret Thatcher as the most successful post-war Prime Minister, just ahead of Clement Attlee. With the exception of Edward Heath, who was judged more favourably by Labour MPs than by Conservatives, evaluations were split along party lines: Tory MPs tended to consider Conservative prime ministers to be more successful than did Labour MPs, and Labour MPs generally gave Labour prime ministers higher scores than did Conservative MPs. In October 2016 the University of Leeds, in conjunction with Woodnewton Associates, surveyed 82