# List of monarchs in Britain by length of reign

The following is a list, ordered by length of reign, of the monarchs of the United Kingdom of Great Britain and Northern Ireland (1927–present), the United Kingdom of Great Britain and Ireland (1801–1922), the Kingdom of Great Britain (1707–1801), the Kingdom of England (871–1707), the Kingdom of Scotland (878–1707), the Kingdom of Ireland (1542–1800), and the Principality of Wales (1216–1542).
Queen Elizabeth II became the longest-reigning monarch in British history on 9 September 2015 when she surpassed the reign of her great-great-grandmother Queen Victoria. On 6 February 2017, she became the first British monarch to celebrate a Sapphire Jubilee, commemorating 65 years on the throne. On 6 February 2022, Elizabeth II became the first British monarch to reign for 70 years, and large-scale celebrations for her Platinum Jubilee occurred on 2 to 5 June. Later that year, Elizabeth II died at the age of 96, after reigning for 70 years and 214 days.

## Elizabeth II: the longest-reigning monarch

On 9 September 2015, Elizabeth II became the longest-reigning British monarch and the longest-reigning known female monarch in world history. On 23 May 2016, her reign surpassed the claimed reign of James Francis Edward Stuart (nicknamed "the Old Pretender"). On 6 February 2022 (at the age of 95 years, 291 days), she became the first British monarch to reign for 70 years and celebrate a platinum jubilee.

## Ten longest-reigning British monarchs

These are the ten longest-reigning monarchs in the British Isles for whom there is reliable recorded evidence.
| Rank | Portrait | Monarch | Age at accession | Reign | Reign | Duration | Duration |
| Rank | Portrait | Monarch | Age at accession | From | To | Days | Years, days |
| 1 | | Elizabeth II of the United Kingdom | 25 years, 291 days | 6 February 1952 | 8 September 2022 | 25,782 | 70 years, 214 days |
| 2 | | Victoria of the United Kingdom | 18 years, 27 days | 20 June 1837 | 22 January 1901 | 23,226 | 63 years, 216 days |
| 3 | | George III of the United Kingdom | 22 years, 143 days | 25 October 1760 | 29 January 1820 | 21,644 | 59 years, 96 days |
| 4 | | James VI of Scotland (James I of England) | 1 year, 35 days | 24 July 1567 | 27 March 1625 | 21,066 | 57 years, 246 days |
| 5 | | Henry III of England | 9 years, 27 days | 28 October 1216 | 16 November 1272 | 20,473 | 56 years, 19 days |
| 6 | | Edward III of England | 14 years, 73 days | 25 January 1327 | 20 June 1377 | 18,410 | 50 years, 147 days |
| 7 | | William I of Scotland | ca. 24 years | 9 December 1165 | 4 December 1214 | 17,892 | 48 years, 360 days |
| 8 | | Llywelyn of Gwynedd | ca. 22 years | 1195 | 11 April 1240 | 16,173–16,902 | c. 44–46 years |
| 9 | | Elizabeth I of England | 25 years, 71 days | 17 November 1558 | 24 March 1603 | 16,198 | 44 years, 127 days |
| 10 | | David II of Scotland | 5 years, 94 days | 7 June 1329 | 22 February 1371 | 15,235 | 41 years, 260 days |

## Complete list of the unitary monarchy

On 1 May 1707, under the Acts of Union 1707, the Kingdom of England united with the Kingdom of Scotland as the Kingdom of Great Britain. Then, on 1 January 1801, the Kingdom of Great Britain united with the Kingdom of Ireland to become the United Kingdom of Great Britain and Ireland, becoming the United Kingdom of Great Britain and Northern Ireland by Act of Parliament in 1927 following the creation of the Irish Free State in 1922.
| Name | Reign | Reign | Duration | Duration |
| Name | From | To | Years, days | Total days |
| Elizabeth II | 6 February 1952 | 8 September 2022 | 70 years, 215 days | 25,783 |
| Victoria | 20 June 1837 | 22 January 1901 | 63 years, 217 days | 23,227 |
| George III | 25 October 1760 | 29 January 1820 | 59 years, 97 days | 21,645 |
| George II | 22 June 1727 | 25 October 1760 | 33 years, 126 days | 12,180 |
| George V | 6 May 1910 | 20 January 1936 | 25 years, 260 days | 9,391 |
| George VI | 11 December 1936 | 6 February 1952 | 15 years, 58 days | 5,536 |
| George I | 1 August 1714 | 11 June 1727 | 12 years, 315 days | 4,698 |
| George IV | 29 January 1820 | 26 June 1830 | 10 years, 149 days | 3,802 |
| Edward VII | 22 January 1901 | 6 May 1910 | 9 years, 105 days | 3,392 |
| Anne | 1 May 1707 | 1 August 1714 | 7 years, 93 days | 2,650 |
| William IV | 26 June 1830 | 20 June 1837 | 6 years, 360 days | 2,552 |
| Charles III | 8 September 2022 | present | 2 years, 159 days | 890 |
| Edward VIII | 20 January 1936 | 11 December 1936 | 327 days | 327 |

## Complete list of the kingdoms
### England

Includes English monarchs from the installation of Alfred the Great as King of Wessex in 871 to Anne (House of Stuart) and the Acts of Union on 1 May 1707, when the crown became part of the Kingdom of Great Britain.
| Name | Reign | Reign | Duration | Duration |
| Name | From | To | Days | Years, days |
| Henry III | 28 October 1216 | 16 November 1272 | 20,473 | 56 years, 19 days |
| Edward III | 25 January 1327 | 21 June 1377 | 18,410 | 50 years, 147 days |
| Elizabeth I | 17 November 1558 | 24 March 1603 | 16,198 | 44 years, 127 days |
| Henry VI | 1 September 1422 31 October 1470 | 4 March 1461 11 April 1471 | 14,064 162 Total: 14,226 | 38 years, 184 days 162 days Total: 38 years, 347 days |
| Æthelred II | 18 March 978 3 February 1014 | 25 December 1013 23 April 1016 | 13,065 810 Total: 13,875 | 35 years, 282 days 2 years, 80 days 37 years, 362 days |
| Henry VIII | 22 April 1509 | 28 January 1547 | 13,795 | 37 years, 281 days |
| Henry I | 5 August 1100 | 1 December 1135 | 12,901 | 35 years, 118 days |
| Henry II | 25 October 1154 | 6 July 1189 | 12,673 | 34 years, 254 days |
| Edward I | 20 November 1272 | 7 July 1307 | 12,646 | 34 years, 229 days |
| Alfred the Great | 24 April 871 | 26 October 899 | 10,412 | 28 years, 185 days |
| Edward the Elder | 27 October 899 | 17 July 924 | 9,029 | 24 years, 264 days |
| Charles II | 29 May 1660 | 6 February 1685 | 9,019 | 24 years, 253 days |
| Charles I | 27 March 1625 | 30 January 1649 | 8,710 | 23 years, 309 days |
| Henry VII | 22 August 1485 | 21 April 1509 | 8,642 | 23 years, 242 days |
| Edward the Confessor | 8 June 1042 | 5 January 1066 | 8,612 | 23 years, 211 days |
| Richard II | 22 June 1377 | 29 September 1399 | 8,134 | 22 years, 99 days |
| James I | 24 March 1603 | 27 March 1625 | 8,039 | 22 years, 3 days |
| Edward IV | 4 March 1461 11 April 1471 | 3 October 1470 9 April 1483 | 3,500 4,381 Total: 7,881 | 9 years, 213 days 11 years, 363 days 21 years, 211 days |
| William I | 12 December 1066 | 9 September 1087 | 7,563 | 20 years, 258 days |
| Edward II | 8 July 1307 | 20 January 1327 | 7,136 | 19 years, 196 days |
| Cnut | 30 November 1016 | 12 November 1035 | 6,921 | 18 years, 347 days |
| Stephen | 22 December 1135 | 25 October 1154 | 6,883 | 18 years, 308 days |
| John | 6 April 1199 | 19 October 1216 | 6,406 | 17 years, 196 days |
| Edgar I | 1 October 959 | 8 July 975 | 5,759 | 15 years, 280 days |
| Æthelstan | 2 August 924 (or 925) | 27 October 939 | 5,564 or 5,199 | 15 years, 86 days or 14 years, 86 days |
| Henry IV | 30 September 1399 | 20 March 1413 | 4,919 | 13 years, 171 days |
| William III (co-ruler with Mary II) | 13 February 1689 | 8 March 1702 | 4,770 | 13 years, 23 days |
| Henry the Young King (junior king under Henry II) | 14 June 1170 | 11 June 1183 | 4,745 | 12 years, 362 days |
| William II | 26 September 1087 | 2 August 1100 | 4,693 | 12 years, 310 days |
| Richard I | 6 July 1189 | 6 April 1199 | 3,561 | 9 years, 274 days |
| Eadred | 26 May 946 | 23 November 955 | 3,468 | 9 years, 181 days |
| Henry V | 21 March 1413 | 31 August 1422 | 3,450 | 9 years, 163 days |
| Edmund I | 27 October 939 | 26 May 946 | 2,403 | 6 years, 211 days |
| Edward VI | 28 January 1547 | 6 July 1553 | 2,351 | 6 years, 159 days |
| Mary II (co-ruler with William III) | 13 February 1689 | 28 December 1694 | 2,144 | 5 years, 318 days |
| Mary I | 19 July 1553 | 17 November 1558 | 1,947 | 5 years, 121 days |
| Anne (also Kingdom of Great Britain) | 8 March 1702 | 30 April 1707 | 1,879 | 5 years, 53 days |
| Harold I | 12 November 1035 | 17 March 1040 | 1,586 | 4 years, 126 days |
| Eadwig | 23 November 955 | 1 October 959 | 1,408 | 3 years, 312 days |
| James II | 6 February 1685 | 11 December 1688 | 1,404 | 3 years, 309 days |
| Edward the Martyr | 9 July 975 | 18 March 978 | 984 | 2 years, 253 days |
| Harthacnut | 17 March 1040 | 8 June 1042 | 813 | 2 years, 83 days |
| Richard III | 26 June 1483 | 22 August 1485 | 788 | 2 years, 57 days |
| Harold II | 5 January 1066 | 14 October 1066 | 282 | 282 days |
| Edmund II | 23 April 1016 | 30 November 1016 | 221 | 221 days |
| Matilda (disputed) | 7 April 1141 | 1 November 1141 | 208 | 208 days |
| Edward V | 9 April 1483 | 26 June 1483 | 78 | 78 days |
| Edgar II | 15 October 1066 | 17 December 1066 | 63 | 63 days |
| Sweyn Forkbeard | 25 December 1013 | 3 February 1014 | 40 | 40 days |
| Ælfweard (disputed) | 17 July 924 | 2 August 924 | 16 | 16 days |
| Jane (disputed) | 10 July 1553 | 19 July 1553 | 9 | 9 days |

### Scotland

Includes Scottish monarchs from the installation of Kenneth I (House of Alpin) in 848 to Anne (House of Stuart) and the Acts of Union on 1 May 1707, when the crown became part of the Kingdom of Great Britain.
| Name | Reign | Reign | Duration | Duration |
| Name | From | To | (days) | (years, days) |
| James VI | 24 July 1567 | 27 March 1625 | 21,066 | 57 years, 246 days |
| William I | 9 December 1165 | 4 December 1214 | 17,892 | 48 years, 360 days |
| Constantine II | 900 | 943 | c. 15,500 | c. 43 years |
| David II | 7 June 1329 | 22 February 1371 | 15,235 | 41 years, 260 days |
| Alexander III | 6 July 1249 | 19 March 1286 | 13,405 | 36 years, 256 days |
| Malcolm III | 17 March 1058 | 13 November 1093 | 13,025 | 35 years, 241 days |
| Alexander II | 4 December 1214 | 6 July 1249 | 12,633 | 34 years, 214 days |
| James I | 4 April 1406 | 21 February 1437 | 11,281 | 30 years, 323 days |
| Malcolm II | 25 March 1005 | 25 November 1034 | 10,837 | 29 years, 245 days |
| James V | 9 September 1513 | 14 December 1542 | 10,688 | 29 years, 96 days |
| David I | 23 April 1124 | 24 May 1153 | 10,623 | 29 years, 31 days |
| James III | 3 August 1460 | 11 June 1488 | 10,174 | 27 years, 313 days |
| Charles II | 30 January 1649 29 May 1660 | 3 September 1651 6 February 1685 | 946 9,019 Total: 9,965 | 2 years, 216 days 24 years, 253 days 27 years, 104 days |
| James IV | 11 June 1488 | 9 September 1513 | 9,220 | 25 years, 90 days |
| Mary I | 14 December 1542 | 24 July 1567 | 8,988 | 24 years, 222 days |
| Charles I | 27 March 1625 | 30 January 1649 | 8,710 | 23 years, 309 days |
| Kenneth II | 971 | 995 | c. 8,700 | c. 23-24 years |
| James II | 21 February 1437 | 3 August 1460 | 8,564 | 23 years, 164 days |
| Edward Balliol (disputed) | 24 September 1332 | 20 January 1356 | 8,518 | 23 years, 118 days |
| Robert I | 25 March 1306 | 7 June 1329 | 8,475 | 23 years, 74 days |
| Robert II | 22 February 1371 | 19 April 1390 | 6,996 | 19 years, 56 days |
| Alexander I | 8 January 1107 | 23 April 1124 | 6,315 | 17 years, 106 days |
| Macbeth | 14 August 1040 | 15 August 1057 | 6,210 | 17 years, 1 day |
| Robert III | 19 April 1390 | 4 April 1406 | 5,828 | 15 years, 350 days |
| Constantine I | 862 | 877 | c. 5,400 | c. 15 years |
| Kenneth MacAlpin | 843 | 13 February 858 | c. 5,100 | c. 14 years |
| William II | 11 May 1689 | 8 March 1702 | 4,683 | 12 years, 301 days |
| Malcolm IV | 24 May 1153 | 9 December 1165 | 4,582 | 12 years, 199 days |
| Giric (co-ruler with Eochaid?) | 878 | 889 | c. 4.000 | c. 11 years |
| Donald II | 889 | 900 | c. 4,000 | c. 11 years |
| Malcolm I | 943 | 954 | c. 3,600 | c. 10-11 years |
| Edgar | 1097 | 8 January 1107 | c. 3,600 | c. 10 years |
| Kenneth III | 997 | 25 March 1005 | c. 2,900 | c. 8 years |
| Indulf | 954 | 962 | c. 2,700 | c. 8 years |
| Duncan I | 25 November 1034 | 14 August 1040 | 2,089 | 5 years, 263 days |
| Mary II | 11 April 1689 | 28 December 1694 | 2,087 | 5 years, 261 days |
| Amlaíb | 971 | 977 | c. 2,000 | c. 5-6 years |
| Anne | 8 March 1702 | 30 April 1707 | 1,879 | 5 years, 53 days |
| Dub | 962 | c. 966-967 | c. 1,800 | c. 5 years |
| Cuilén | c. 966-967 | 971 | c. 1,800 | c. 5 years |
| Domnall mac Ailpín | 858 | 13 April 862 | c. 1.300 | c. 4 years |
| James VII | 6 February 1685 | 11 December 1688 (claimed until 16 September 1701) | 1,404 (claimed 6,065) | 3 years, 309 days claimed 16 years, 222 days |
| Margaret | 25 November 1286 | 26 September 1290 | 1,401 | 3 years, 305 days |
| John Balliol | 17 November 1292 | 10 July 1296 | 1,331 | 3 years, 236 days |
| Donald III | 13 November 1093 | 1097 | c. 1,000 | c. 3-4 years |
| Áed mac Cináeda | 877 | 878 | c. 365 | c. 1 year |
| Constantine III | 995 | 997 | c. 485 | 16 months |
| Lulach | 15 August 1057 | 17 March 1058 | 212 | 212 days |
| Duncan II | May 1094 | 12 November 1094 | c. 195 | "less than 7 months" |

### Ireland

The High King of Ireland (846–1198) was primarily a titular ruler (with the exception of Ruaidrí Ua Conchobair who was regarded as the first "King of Ireland"). The later Kingdom of Ireland (1542–1800) came into being under the Crown of Ireland Act 1542, the long title of which was "An Act that the King of England, his Heirs and Successors, be Kings of Ireland". In 1801 the Irish crown became part of the United Kingdom of Great Britain and Ireland.
| Name | Reign | Reign | Duration | Duration |
| Name | From | To | (days) | (years, days) |
| Ruaidrí Ua Conchobair | 1166 | 1193 | | c. 26-27 years |
| Edward Bruce (disputed) | June 1315 | 14 October 1318 | | c. 3 years, 100 days |
| Brian Ua Néill (disputed) | 1258 | 1260 | | c. 1-2 years |

## List of the Principalities
### Gwynedd (incomplete list)

The Principality (or Kingdom) of Gwynedd (5th century–1216), located in northwest Wales, was one of the most prominent early medieval Welsh kingdoms. Its rulers were often acclaimed as "King of the Britons," symbolizing their influence over other Welsh territories and their resistance to external threats. Gwynedd faced repeated challenges, including civil wars, Saxon incursions, and Norman invasions, which gradually eroded its dominance. In 1216, it transitioned into the Principality of Wales, although the title "Prince of Wales" was not formally adopted until the 1240s under the leadership of Llywelyn ap Gruffudd, also known as Llywelyn the Last.
Gwynedd’s heartland was the mountainous region of Snowdonia, which provided natural defenses and contributed to its resilience against invaders. The kingdom played a central role in preserving Welsh identity, language, and culture during a period of significant upheaval in Britain.
| Name | Reign | Reign | Duration | Duration |
| Name | From | To | (days) | (years, days) |
| Gruffudd ap Cynan | 1081 | 1137 | | c. 55-56 years |
| Llywelyn the Great | 1195 | 11 April 1240 | >16,172 | c. 44-45 years |
| Owain Gwynedd | 1137 | 1170 | >11,688 | c. 33 years |
| Dafydd ab Owain Gwynedd | 1170 | 1195 | >8,766 | c. 25 years |
| Cynan ab Iago | 1023 | 1039 | 5840 | 16 years |
| Hywel ab Owain Gwynedd | 1170 | 1170 | | <1 year |

### Wales (complete list)

The Principality of Wales (1216–1542) was a client state of England for much of its history, except for brief periods when it was de facto independent under a Welsh Prince of Wales (see House of Aberffraw). From 1301 it was first used as a title of the English (and later British) heir apparent. The Laws in Wales Acts 1535 and 1542 formally incorporated all of Wales within the Kingdom of England.
| Name | Reign | Reign | Duration | Duration |
| Name | From | To | (days) | (years, days) |
| Llywelyn ap Gruffudd | 1253 | 11 December 1282 | >10,572 | c. 29 years |
| Owain Glyndŵr (disputed) | 16 September 1400 | c. 1416 | >5,585 | c. 16 years |
| Owain Goch ap Gruffydd | 25 February 1246 | 1255 | >3,000 | c. 9 years |
| Owain Lawgoch (disputed) | May 1372 | July 1378 | >2,221 | c. 6 years |
| Dafydd ap Llywelyn | 12 April 1240 | 25 February 1246 | 2,145 | 5 years, 319 days |
| Dafydd ap Gruffydd | 11 December 1282 | 3 October 1283 | 296 | 296 days |