|TITLES OF NOBILITY|
|Emperor / Empress|
|King / Queen|
|Prince / Princess|
|Grand Duke / Grand Duchess|
|Duke / Duchess|
|Earl / Countess|
|Baron / Baroness|
A grand duke or a grand duchess was historically the ruler or monarch of a Grand Duchy, or a high-ranking member of the Nobility.
The Star Kingdom of Manticore originally created one planetary grand duchy for each of the three occupied planets of the Manticore Binary System. With the creation of the Star Empire of Manticore, it is envisioned that a grand duchy will be created for each new planet joining the empire. As there is only a single grand duchy per planet, this is the highest ranking and least numerous type of peerage.
Grand duchies are held as territories subsidiary to the Star Kingdom, so SKM dukes and duchesses, while they are the administrators of their territories, are still subjects of the sovereign rather than monarchs of their duchies.
Star Kingdom of Manticore
Forms of Address
A grand duke or grand duchess is addressed as "Your Grace." Grand dukes are referred to in the third person as "His Grace" or "the Grand Duke of Title" or "His Grace the Grand Duke of Title." Grand duchesses are referred to in the third person as "Her Grace" or "The Grand Duchess of Title" or "Her Grace the Grand Duchess of Title." Unlike earls/countesses or barons/baronesses, they are never referred to as "Lord Title" or "Lady Title."
A Grand Duke or Grand Duchess with military rank may be referred to by their rank and title instead of their rank and given name. Formal usage: Admiral the Grand Duke of Gryphon. Less formal usage: Admiral Gryphon.
In the peerage of the Star Kingdom of Manticore and in TRMN a grand ducal title may be held by a male or female. Grand dukedoms, like all other Manticoran peerages, are hereditary and typically the current holder will designate their eldest child as their heir, without regard to their gender. The spouse of the title holder is afforded the same title, without regard for the gender of the title holder.
The cadet (heir) of a grand duke or grand duchess (usually their eldest child) is addressed as "My Lord" (if male) or "My Lady" (if female), or "Lord/Lady [first name]" and is referred to in the third person as "Lord Firstname Lastname" (if male) or "Lady Firstname Lastname" (if female).
Children of a grand duke or grand duchess (other than the cadet) are referred to in the third person as "The Honorable Firstname Lastname." This is customarily abbreviated in written form as "Hon. Firstname Lastname." There is no special form of address for younger children of a grand duke or grand duchess.