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 Byron
Baron Byron, of Rochdale in the County Palatine of Lancaster, is a title in the Peerage of England. It was created in 1643 by letters patent for John Byron, 1st Baron Byron, a Cavalier general and former Member of Parliament. The peerage was created with remainder to the heirs male of his body, failing, to his six brothers: Richard, William, Thomas, Robert, Gilbert, and Philip, and the heirs male of their bodies. Lord Byron died childless and was succeeded according to the special remainder by his next eldest brother Richard, the second Baron.