- You may also be looking for the Sovereign-class Federation starship, or the Sovereign Guard.
Sovereign was the title in use on several worlds.
Marouk was the Acamarian sovereign in 2366. (TNG: "The Vengeance Factor")
In the Delta Quadrant, a world known as The Waters was ruled by 47 regional sovereigns, united under the Monean Maritime Sovereignty. (VOY: "Thirty Days")