Dukes in the United Kingdom
Duke, in the United Kingdom, is the highest-ranking hereditary title in all four peerages of the British Isles. A duke thus outranks all other holders of titles of nobility (marquess, earl, viscount and baron).
Grandee
Grandee (; , ; , ) is an official aristocratic title conferred on some Spanish nobility and, to a lesser extent, Portuguese nobility. Holders of this dignity enjoyed similar privileges to those of the peerage of France during the Ancien Régime, but unlike in Great Britain, they were not organised into political groupings. "Grandee of Spain" is the highest dignity of nobility in all of Europe, due to its privileges having been greater than those of other similar European dignities, such as the peers of France or the peers of Great Britain. All Dukedoms are automatically attached to a Grandeeship yet only a few Marquessates, Countships, Viscountcies, Baronies and Lordships have the distinction. A single person can be a Grandee of Spain multiple times, as Grandeeships are attached, with the exception of a few cases, to a title and not an individual. Consequently, nobles in Spain with more than one title, most notably the Duchess of Medinaceli and the Duke of Alba, are Grandees 10 and 9 times respectively.