Records of Prime Ministers of the United Kingdom of . From oldest to youngest: The most recent death of a former Prime Minister was that of Baroness Thatcher (served 1979–90) on 8 April 2013 (aged 87 years, 177 days). Seven Prime Ministers have died in office: Spencer Perceval is the only British Prime Minister to have been assassinated. Sir Robert Peel, Margaret Thatcher and John Major survived assassination attempts in 1843, 1984 and 1991 respectively. Sir Henry Campbell-Bannerman and Bonar Law each resigned during their respective final illnesses. Law died five months after his resignation, but Campbell-Bannerman lived only another 19 days, dying at 10 Downing Street, the
Historical rankings of Prime Ministers of the United Kingdom the scores could then be calculated and a league table based on the mean scores. The five Labour prime ministers were, on average, judged to have been the most successful, with a mean of 6.0 (median of 5.9). The three Liberal PMs averaged 5.8 (median of 6.2) and the twelve Conservative PMs 4.8 (median of 4.1). In 2010, the University of Leeds and Woodnewton Associates carried out a survey of 106 academics who specialised in British politics or British history, to rank the performance of all 12 prime ministers who served between 1945 and 2010. Churchill's ranking was thus determined