Sovereign
You may also be looking for the  Federation starship, or the Sovereign Guard.

Sovereign was the title in use on several worlds.

Marouk was the Acamarian sovereign in 2366. ()

In the Delta Quadrant, a world known as The Waters was ruled by 47 regional sovereigns, united under the Monean Maritime Sovereignty. ()

External link

nl:Soeverein
de:Souverän
Titles