Boris Johnson's resignation today puts him among the top four shortest serving British Prime Ministers in the post-war period - and means he has lasted less time in office than Theresa May.
Mr Johnson became Prime Minister on 24 July 2019, and has therefore been in post for two years and 348 days.
In comparison, Theresa May, who became Prime Minister in 2016, served for three years and 12 days until 2019.
Below is the full list of post-war Prime Ministers in order of how long they remained in the top job.
Post-war PMs - who lasted the longest in the top job?
Alec Douglas-Home - 1963 – 1964 - 364 days
Anthony Eden - 1955 – 1957 - 1 year and 279 days
Gordon Brown - 2007 – 2010 - 2 years and 319 days
Boris Johnson - 2019 – present - 2 years and 348 days
James Callaghan - 1976 – 1979 - 3 years and 30 days
Theresa May - 2016 – 2019 - 3 years and 12 days
Winston Churchill - 1951 – 1955 - 3 years and 162 days
Edward Heath - 1970 – 1974 - 3 years and 259 days
Harold Wilson - 1974 – 1976 - 5 years and 247 days
David Cameron - 2010 – 2016 - 6 years and 64 days
Clement Attlee - 1945 – 1951 - 6 years and 93 days
John Major - 1990 – 1997 - 6 years and 156 days
Harold Macmillan - 1957 – 1963 - 6 years and 282 days
Tony Blair - 1997 – 2007 - 10 years and 57 days
Margaret Thatcher - 1979 – 1990 - 11 years and 209 days