By the time the words came into English they already meant "ruler."
The term khan means ruler; but it follows the name, instead of coming first.
Shah is a Persian word which means the king or ruler of a country.
It means 'ruler of the home' or 'lord of the house'.
The name of the king was Prithviraj, which means "ruler of the earth."
You have held to the word king, but it could mean ruler, thane or laird.
The specific name is derived from Latin regula (meaning a straight length or ruler).
Khosrau when used as a title means king or ruler.
Slavic in origin, it means lord, ruler, winner or warrior.
Frederick is a masculine given name meaning "peaceful ruler."