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.
Hereditary peer
The peerage has traditionally been associated with high gentry, the British nobility, and in recent times, the Conservative Party. Only a tiny proportion of wealthy people are peers, but the peerage includes a few of the very wealthiest, such as Hugh Grosvenor (the Duke of Westminster) and Lord Salisbury of Hatfield House. Most of the largest stately homes belong to the National Trust due to forms of estate tax. A few peers own one or more of England's largest estates passed down through inheritance, particularly those with medieval roots: until the late 19th century the dominant English and Scottish land division on death was primogeniture.