* Ruler: This is the most straightforward and general term.
* Leader: This implies guidance and influence, not necessarily absolute power.
* Monarch: This specifically refers to a king or queen.
* Sovereign: This implies supreme power and authority.
* Governor: This refers to a ruler of a state or province.
* President: This refers to the head of state in a republic.
* Dictator: This implies ruling through force and oppression.
* Tyrant: Similar to dictator, but with a stronger emphasis on cruelty and injustice.
The best word to use will depend on the specific situation and the nature of the person's rule.