Peerage of the United Kingdom
The Peerage of the United Kingdom comprises most peerages created in the United Kingdom of Great Britain and Ireland after the Acts of Union in 1801, when it replaced the Peerage of Great Britain. New peers continued to be created in the Peerage of Ireland until 1898.
The House of Lords Act 1999 reformed the House of Lords. Until then, all peers of the United Kingdom were automatically members of the House of Lords. However, from that date, most of the hereditary peers ceased to be members, whereas the life peers retained their seats. All hereditary peers of the first creation, and all surviving hereditary peers who had served as Leader of the House of Lords, were offered a life peerage to allow them to sit in the House should they wish.
Some holders of the Peerage of United Kingdom was created for peers in the Peerage of Scotland and Peerage of Ireland as they did not have an automatic seat in the House of Lords until the Peerage Act 1963 which gave Scottish Peers an automatic right to sit in the Lords.
Dukes in the Peerage of the United Kingdom
| Shield | Title | Creation | Grantee | Reason | Monarch |
| The Duke of Wellington Marquess of Douro | 11 May 1814 |  The 1st Marquess of Wellington | Military Peerage–Army. | The Prince Regent on behalf of King George III | |
| The Duke of Sutherland | 28 January 1833 |  The 2nd Marquess of Stafford | King William IV | ||
| The Duke of Westminster | 27 February 1874 | The 3rd Marquess of Westminster | Queen Victoria | ||
| The Duke of Gordon Earl of Kinrara | 13 January 1876 |  The 6th Duke of Richmond | Queen Victoria | ||
| The Duke of Albany Earl of Clarence Baron Arklow | 24 May 1881 | Prince Leopold | Currently suspended. | Queen Victoria | |
| The Duke of Argyll | 7 April 1892 |  The 8th Duke of Argyll | His descendants sat in the House of Lords until 1963. | Queen Victoria | |
| The Duke of Fife Earl of Macduff | 24 April 1900 | The 1st Duke of Fife | Queen Victoria | ||
| The Duke of Gloucester Earl of Ulster Baron Culloden | 31 April 1928 | Prince Henry | On his 28th birthday. | King George V | |
| The Duke of Kent Earl of St Andrews Baron Downpatrick | 12 October 1934 | Prince George | In anticipation of his forthcoming marriage to Princess Marina of Greece and Denmark. | King George V | |
| The Duke of Edinburgh Earl of Merioneth Baron Greenwich | 20 November 1947 | Sir Philip Mountbatten | On his wedding day to Princess Elizabeth. | King George VI | |
| The Duke of York Earl of Inverness Baron Killyleagh | 23 July 1986 | Prince Andrew | On his wedding day to Sarah Ferguson. | Queen Elizabeth II | |
| The Duke of Cambridge Earl of Strathearn Baron Carrickfergus | 29 April 2011 | Prince William of Wales | On his wedding day to Catherine Middleton. | Queen Elizabeth II | |
| The Duke of Sussex Earl of Dumbarton Baron Kilkeel | 18 May 2018 | Prince Henry of Wales | On his wedding day to Meghan Markle. | Queen Elizabeth II |
Marquesses in the Peerage of the United Kingdom
Earls in the Peerage of the United Kingdom
Viscounts in the Peerage of the United Kingdom
Barons in the Peerage of the United Kingdom
Extinct peerages since the Passage of the [House of Lords Act 1999]
Extinct earldoms
Extinct viscountcies
Extinct baronies
Current titles without heirs
Current UK Peers
Current Scottish and Irish Peers with United Kingdom titles
Marquesses, earls, viscounts and barons are all addressed as 'Lord X', where 'X' represents either their territory or surname pertaining to their title. Marchionesses, countesses, viscountesses and baronesses are all addressed as 'Lady X'. Dukes and duchesses are addressed just as 'Duke' or 'Duchess' or, in a non-social context, 'Your Grace'.Lists of peers
- 31 Dukes: see List of dukes in the peerages of Britain and Ireland
- 34 Marquesses: see List of marquesses in the peerages of Britain and Ireland
- 193 Earls and countesses: see List of earls in the peerages of Britain and Ireland
- 112 Viscounts: see List of viscounts in the peerages of Britain and Ireland
- 1,187 Barons: see List of barons in the peerages of Britain and Ireland
- Women: see List of peerages created for women and List of peerages inherited by women