# List of prime ministers of the United Kingdom by length of tenure
The length of tenure of a prime minister of the United Kingdom is the total time that person has held the office of head of His Majesty's Government. Fifty-seven individuals (54 men and 3 women) have served as prime minister; the first and longest serving was Sir Robert Walpole (1721 to 1742), and the shortest serving was [Liz Truss](https://www.edgepedia.org/liz-truss), who held the office for seven weeks (49 days) in 2022.[1](https://commonslibrary.parliament.uk/research-briefings/cbp-9880/) • [2](https://www.cfr.org/articles/the-uk-will-have-its-seventh-prime-minister-in-a-decade-what-happened-to-the-others)
| Key fact | Detail |
|---|---|
| Total holders | 57 individuals (54 men and 3 women) have served as Prime Minister of the UK[1](https://commonslibrary.parliament.uk/research-briefings/cbp-9880/) |
| Longest serving | Sir Robert Walpole, 1721 to 1742, the first holder of the office[1](https://commonslibrary.parliament.uk/research-briefings/cbp-9880/) |
| Shortest serving | Liz Truss, 49 days in 2022, the shortest tenure in British history[2](https://www.cfr.org/articles/the-uk-will-have-its-seventh-prime-minister-in-a-decade-what-happened-to-the-others) • [3](https://apnews.com/article/9e9c4d690254e8b9e8b7c61e2ea5b78b) |
| Postwar count | 19 prime ministers since 1945; 12 of them first took office between general elections[4](https://commonslibrary.parliament.uk/research-briefings/sn04256/) |
| Tenure and reputation | The top eight postwar prime ministers in MPs' 2023 rankings served on average 7 years and 356 days; the bottom eight averaged 2 years and 124 days[5](https://onlinelibrary.wiley.com/doi/10.1111/1467-923X.13364) |
| Recent turnover | Andy Burnham became prime minister on 20 July 2026, the seventh in just over a decade[6](https://www.gov.uk/government/ministers/prime-minister) • [7](https://www.itv.com/news/2026-07-20/andy-burnham-becomes-uks-7th-prime-minister-in-a-decade-how-did-we-get-here) |
## Extremes of tenure
**Longest service.** Sir Robert Walpole, regarded as the first prime minister, held the office from 1721 to 1742, a span the House of Commons Library identifies as the longest of any holder.[1](https://commonslibrary.parliament.uk/research-briefings/cbp-9880/) The office itself evolved over three centuries and is rarely found in statute; the Political and Constitutional Reform Committee observed in 2014 that it is "impossible to point to a single point in history when the post was created."[1](https://commonslibrary.parliament.uk/research-briefings/cbp-9880/)
**Shortest service.** Liz Truss resigned in October 2022 after 49 days in office, the shortest premiership in British history.[2](https://www.cfr.org/articles/the-uk-will-have-its-seventh-prime-minister-in-a-decade-what-happened-to-the-others) • [3](https://apnews.com/article/9e9c4d690254e8b9e8b7c61e2ea5b78b) Her mini-budget of drastic tax cuts caused economic and political chaos and destroyed her support in the Conservative Party.[3](https://apnews.com/article/9e9c4d690254e8b9e8b7c61e2ea5b78b) Among twentieth-century premiers, [Henry Campbell-Bannerman](https://www.edgepedia.org/henry-campbell-bannerman)'s Liberal tenure lasted two years and 122 days, from 1905 to 1908.[8](https://www.the-independent.com/news/uk/boris-johnson-downing-street-gordon-brown-anthony-eden-margaret-thatcher-b2158063.html)
## Postwar prime ministers and their terms
Nineteen people have served as prime minister since 1945. Twelve of them first took office between general elections, including [Winston Churchill](https://www.edgepedia.org/winston-churchill) in 1940; five of those continued in office after winning an election while serving as prime minister, and Churchill became prime minister for a second time after a period in opposition.[4](https://commonslibrary.parliament.uk/research-briefings/sn04256/) The postwar holders and their periods of office are:[9](https://www.gov.uk/government/history/past-prime-ministers)
| Prime minister | Party | Period(s) of office |
|---|---|---|
| Clement Attlee | Labour | 1945 to 1951 |
| Sir Winston Churchill | Conservative | 1940 to 1945; 1951 to 1955 |
| Sir Anthony Eden | Conservative | 1955 to 1957 |
| Harold Macmillan | Conservative | 1957 to 1963 |
| Sir Alec Douglas-Home | Conservative | 1963 to 1964 |
| Harold Wilson | Labour | 1964 to 1970; 1974 to 1976 |
| Sir Edward Heath | Conservative | 1970 to 1974 |
| James Callaghan | Labour | 1976 to 1979 |
| Baroness Thatcher | Conservative | 1979 to 1990 |
| Sir John Major | Conservative | 1990 to 1997 |
| Sir Tony Blair | Labour | 1997 to 2007 |
| Gordon Brown | Labour | 2007 to 2010 |
| The Rt Hon Lord Cameron | Conservative | 2010 to 2016 |
| The Rt Hon Theresa May | Conservative | 2016 to 2019 |
| The Rt Hon Boris Johnson | Conservative | 2019 to 2022 |
| The Rt Hon Elizabeth Truss | Conservative | 2022 to 2022 |
| The Rt Hon Rishi Sunak | Conservative | 2022 to 2024 |
| The Rt Hon Sir Keir Starmer | Labour | 2024 to 2026 |
Several of these premiers served non-consecutive terms, so total tenure differs from a single continuous spell. Wilson and Churchill each returned to the office after a period in opposition.[4](https://commonslibrary.parliament.uk/research-briefings/sn04256/) • [9](https://www.gov.uk/government/history/past-prime-ministers)
## Tenure and historical reputation
Length of service is strongly associated with how prime ministers are judged. A 2023 survey of Members of Parliament by researchers at [Royal Holloway, University of London](https://www.edgepedia.org/royal-holloway-university-of-london), asked MPs to score each postwar prime minister from Attlee to Truss on a 0 to 10 scale; it found a very strong positive correlation between total years in office and mean score.[5](https://onlinelibrary.wiley.com/doi/10.1111/1467-923X.13364) The top eight prime ministers in the 2023 rankings had served, on average, seven years and 356 days, while the bottom eight averaged two years and 124 days.[5](https://onlinelibrary.wiley.com/doi/10.1111/1467-923X.13364) Thatcher (7.8), Attlee (7.4) and Blair (7.4) received the highest scores; Truss, at 0.7, received by far the lowest.[5](https://onlinelibrary.wiley.com/doi/10.1111/1467-923X.13364)
[Roy Jenkins](https://www.edgepedia.org/roy-jenkins) reckoned it "essential to have a cumulative period in office of at least five years in order to rank as a Prime Minister of major impact," meaning a significant influence on government and public policy. By that criterion Thatcher, Attlee and Blair, who each served at least six years, are the most obvious candidates for major-impact premiers since 1945.[5](https://onlinelibrary.wiley.com/doi/10.1111/1467-923X.13364) Electoral record also shaped the scores: the five multiple-election winners averaged 6.9 in 2023, against 4.8 for the seven single-election winners and 3.4 for the four prime ministers who never won a general election.[5](https://onlinelibrary.wiley.com/doi/10.1111/1467-923X.13364)
Tenure benchmarks also appear in comparisons of individual premierships. When [Boris Johnson](https://www.edgepedia.org/boris-johnson) left office he had outrun eight of the 22 other people who had served as prime minister since 1900, and a successor defeated at an early election would have ranked as the fifth shortest serving premier since 1900, behind [Gordon Brown](https://www.edgepedia.org/gordon-brown) but just ahead of Campbell-Bannerman.[8](https://www.the-independent.com/news/uk/boris-johnson-downing-street-gordon-brown-anthony-eden-margaret-thatcher-b2158063.html)
## Recent turnover
The pace of change at 10 [Downing Street](https://www.edgepedia.org/downing-street) has increased sharply. [Andy Burnham](https://www.edgepedia.org/andy-burnham) became prime minister on 20 July 2026, replacing [Keir Starmer](https://www.edgepedia.org/keir-starmer), whose tenure lasted about two years; Burnham is the seventh prime minister in just over a decade.[6](https://www.gov.uk/government/ministers/prime-minister) • [7](https://www.itv.com/news/2026-07-20/andy-burnham-becomes-uks-7th-prime-minister-in-a-decade-how-did-we-get-here) • [10](https://apnews.com/article/2cbc843c2f81ca7046b022c419e62769) The Associated Press notes that this rapid turnover is a first in British modern political history, while the preceding four decades saw just six prime ministers.[3](https://apnews.com/article/9e9c4d690254e8b9e8b7c61e2ea5b78b) Commentators have attributed the volatility to economic instability, political polarization, and personal scandals.[2](https://www.cfr.org/articles/the-uk-will-have-its-seventh-prime-minister-in-a-decade-what-happened-to-the-others) Since 1974, no prime minister had entered and left office through winning and then losing a general election, a pattern that makes mid-parliament changes of prime minister the dominant route out of the office in recent decades.[4](https://commonslibrary.parliament.uk/research-briefings/sn04256/)
## References
1. [The office and functions of the Prime Minister, House of Commons Library](https://commonslibrary.parliament.uk/research-briefings/cbp-9880/)
2. [The UK Has Its Seventh Prime Minister in a Decade. What Happened to the Others?, Council on Foreign Relations](https://www.cfr.org/articles/the-uk-will-have-its-seventh-prime-minister-in-a-decade-what-happened-to-the-others)
3. [A look at the quick succession of British prime ministers in the past 10 years, AP News](https://apnews.com/article/9e9c4d690254e8b9e8b7c61e2ea5b78b)
4. [Prime Ministers, House of Commons Library research briefing SN04256](https://commonslibrary.parliament.uk/research-briefings/sn04256/)
5. [The Good, the Not so Good, and Liz Truss: MPs' Evaluations of Postwar Prime Ministers, The Political Quarterly (2024)](https://onlinelibrary.wiley.com/doi/10.1111/1467-923X.13364)
6. [Prime Minister, GOV.UK](https://www.gov.uk/government/ministers/prime-minister)
7. [Andy Burnham becomes UK's 7th prime minister in a decade, ITV News](https://www.itv.com/news/2026-07-20/andy-burnham-becomes-uks-7th-prime-minister-in-a-decade-how-did-we-get-here)
8. [Boris Johnson's tenure as PM: How it compares to his predecessors, The Independent](https://www.the-independent.com/news/uk/boris-johnson-downing-street-gordon-brown-anthony-eden-margaret-thatcher-b2158063.html)
9. [Past Prime Ministers, GOV.UK](https://www.gov.uk/government/history/past-prime-ministers)
10. [The Latest: Andy Burnham replaces Keir Starmer as UK prime minister, AP News](https://apnews.com/article/2cbc843c2f81ca7046b022c419e62769)
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*Topic: Encyclopedia › Society and history › Politics and government › Government and public administration › Prime ministers, cabinets, and ministries › Prime ministers of the United Kingdom*
*Initially written Sep 17, 2026 · Reviewed: Sep 30, 2026; Oct 25, 2026 · Edited: Sep 30, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
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