Royal dukedoms in the United Kingdom
In the British peerage, a royal duke is a member of the British royal family, entitled to the titular dignity of prince and the style of "His Royal Highness" who holds a dukedom. Dukedoms are the highest titles in the British roll of peerage and the holders of these particular dukedoms are Princes of the Blood Royal. The holders of the dukedoms are royal not the titles themselves. They are titles created and bestowed on legitimate sons and male-line grandsons of the British monarch, usually upon reaching their majority or marriage. The titles can be inherited but cease to be called "royal" once they pass beyond the grandsons of a monarch. As with any peerage, once the title becomes extinct, it may subsequently be recreated by the reigning monarch at any time.
Peerages in the United Kingdom
This right, entitlement or "title", began to be granted by decree in the form of a Writ of Summons from 1265 and by Letters Patent from 1388. Additionally, many holders of smaller fiefdoms "per baroniam" ceased to be summoned to parliament, resulting in baronial status becoming personal rather than territorial. Feudal baronies had always been hereditable by primogeniture, but on condition of payment of a fine, termed "relief", derived from the Latin verb "levo" to lift up, meaning a "re-elevation" to a former position of honour. Baronies and other titles of nobility became unconditionally hereditable on the abolition of feudal tenure by the Tenures Abolition Act of 1660, and non-hereditable titles began to be created in 1876 for Law Lords, and in 1958 for Life Peers.