Cream of the crop
The title of Duke in the United Kingdom represents the pinnacle of the hierarchical system of nobility and is traditionally granted to princes upon their marriage. The wife of a duke is bestowed the title of duchess. Historically, being named Duke of a region like Sussex meant actual governance or ownership of that area.
However, in contemporary times, these titles are largely ceremonial and do not confer any specific territorial authority or ownership. The tradition of attaching a geographic designation to dukedoms originates from the feudal system, where land and titles were closely linked.