The seven shortest-serving UK prime ministers:
1. George Canning
Mr. Canning was the shortest serving prime minister of all time, lasting just 119 days in office. According to Gov, before serving as prime minister, he was served as foreign secretary before replacing Lord Liverpool as PM in 1827 and dying five months later of pneumonia.
2. The Viscount Godereich (Frederick Robinson)
Robinson lasted just 130 days in power. Professor Arthur Burns wrote that he was known for his speeches and supported the abolition of slavery, but less than a year after taking power he was “humiliatingly asked to arrange his own replacement” by the King in 1828.
3. Bonar Law
Next came the relatively more modern Bonar Law, who is probably the person on this list that is most well-known. Born in Canada and lasting 211 days, this Conservative was asked to form a government when David Lloyd George resigned in 1922, according to Gov.UK. But his time in power was cut short due to illness, leading him to resign and die shortly afterwards.
4. William Cavendish (Duke of Devonshire)
5. William Petty (Earl of Shelburne)
Born in Ireland, this prime minister was in power between 1782 and 1783. The Whig was prime minister when the USA became independent of the British Empire. He eventually resigned as a result of “characteristically clumsy dealings with colleagues”, according to Professor Arthur Burns.
6. John Stuart (3rd Earl of Bute)
According to Andrew Thompson, Stuart was a Scottish aristocrat who is known for his unpopular tax on cider in 1763, as well as “supposedly improper relations with George III’s mother.” He lasted just 317 days in power.
7. Theresa May
Currently, Theresa May is the UK's seventh shortest-serving prime minister of all time. After losing her party’s majority in June, her position is rocky, but if she lasts just over a week more she will have made it to a year and passed Sir Alec Douglas-Home who lasted just 362 days. The former Conservative leader resigned when he lost the 1964 election to Harold Wilson who won a slim majority.