Duke
A duke is a high-ranking Westarctican peer. It is below that of prince/ princess and above that of marquis/ marquise. Dukedoms/ Duchies are often named for large geographic features like peninsulas or mountain ranges.
It should be noted that although a Westarctican noble might bear the title of duke or duchess, he or she may actually be the prince or princess of a given territory. There are no other Westarcticsan titles which work this way.
It should also be noted that a person may hold the Westarctican title of "duke" or "duchess" while simultaneously being a king or a grand duke in some other system of peerage. For example, King Christopher of Vikesland is a Westarctican prince whose Westarctican title is Duke of Hudson.