What are Dukes?

Answer 1

A duke is a member of the nobility at the highest level. A duke ranks above a marquess, which is above an earl or count. A duke is below a prince.

A duke could be a sovereign monarch, as many of the medieval Dukes of Brittany were, and the Archduke of Luxembourg is today. More commonly, dukes were vassals with very extensive holdings. Eleanor of Aquitaine is said to have had about a third of France.

Originally, dukes were powerful military leaders. The title was applied to important military leaders of the ancient Roman army who could not be regular officers because they were not born in the empire, so there were a number of Germanic people who were Roman dukes rather than being generals.