dethroner
/dɛˈθroʊnər/Definitions
1. noun
A person or thing that deposes or removes someone or something from a throne or position of power.
“The dethroner of the long-reigning monarch was a young general with a clever strategy.”
2. verb
To remove someone or something from a throne or position of power.
“The king was dethroned by a coup led by his own advisors.”