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 Historical rankings of Prime Ministers of the United Kingdom "The Times" constructed a poll for the first time of all British prime ministers in the lead-up to the 2010 general election. Before this there were two polls in 1999 and 2000, carried out by BBC Radio 4 and the British Politics Group—both consulted only a relatively small number of experts. A wider-reaching poll was conducted in 2004 by the University of Leeds and Ipsos MORI. All rankings involved only prime ministers from the 20th and 21st centuries. In 2004, the University of Leeds and Ipsos Mori conducted an online survey