List of dukes in the peerages of Britain and Ireland
| Extant | All |
|---|---|
| Dukes | Dukedoms |
| Marquesses | Marquessates |
| Earls | Earldoms |
| Viscounts | Viscountcies |
| Barons | Baronies |
| Baronets | Baronetcies |
This is a list of the 30 present and extant dukes in the peerages of the Kingdom of England, Kingdom of Scotland, Kingdom of Great Britain, Kingdom of Ireland, United Kingdom of Great Britain and Ireland, and the United Kingdom of Great Britain and Northern Ireland 1927 and after. For a more complete historical listing, including extinct, dormant, abeyant, forfeit dukedoms in addition to these extant ones, see List of dukedoms in the peerages of Britain and Ireland.
In the peerage of England, the title of Duke was created 74 times (using 40 different titles: the rest were recreations). Twice a woman was created a Duchess in her own right (but only for life). Out of the 74 times, 37 titles are now extinct (including the two women's), 16 titles were forfeit or surrendered, 10 were merged with the crown, and 11 are extant (see list below). The first, Cornwall, is a title that automatically goes to the heir apparent (if and only if he is also the eldest living son of the Sovereign). One of the duchies that was merged into the crown, Lancaster, still provides income to the sovereign. All but two of the titles which became extinct did so before 1800 (the Duke of Leeds became extinct in 1964 and the Duke of Portland in 1990). The last English dukedom to be forfeit became so in 1715. The last British dukedom to become extinct was the title of Duke of Portland in 1990.
The oldest six titles – created between 1337 and 1386 – were Duke of Cornwall (1337), Duke of Lancaster (1351), Duke of Clarence (1362), Duke of York (1385), Duke of Gloucester (1385), and Duke of Ireland (1386). The Duke of Ireland was a title used for only two years and is somewhat confusing since only a small portion of Ireland was really under the control of England in 1386; it is not to be confused with the dukedoms of the peerage of Ireland. Clarence has not been used since 1478, when George (the brother of Edward IV) was executed for treason. (However Clarence has since been used as half of a double title, most recently until 1892 when Victoria's grandson (and son of the Prince of Wales), the Duke of Clarence and Avondale, died at the age of 28.) The titles of Duke of York and the Duke of Gloucester have both become extinct more than once and been re-created as titles within the peerage of the United Kingdom. Both titles are reserved for princes (and their descendants). The Duke of Lancaster has merged with the Crown and so is held by the monarch. On 29 September 1397, in an unprecedented move six dukedoms were created on a single day. None of these titles is extant.
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