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 of 258 academics who specialised in 20th-century British history and/or politics. There were 139 replies to the survey, a return rate of 54%—by far the most extensive survey done so far. The respondents were asked, among other historical questions, to rate all the 20th-century prime ministers (PM) in terms of their success and asking them to assess the key characteristics of successful PMs. Respondents were asked to indicate on a scale of 0 to 10 how successful or unsuccessful they considered each PM to have been in office (with 0 being highly unsuccessful and 10 highly successful). A mean of