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.
Baron Margadale
Baron Margadale, of Islay in the County of Argyll, is a title in the Peerage of the United Kingdom. It was created on 1 January 1965 for the Conservative politician John Morrison. the title is held by his grandson, the third baron, who succeeded his father in 2003. The barony of Margadale is the most recent hereditary barony granted to an individual outside the royal family, and so Lord Margadale is the most junior of Britain's hereditary peers. The barony is named after the area of Margadale, in Islay.