roi soleil
/ˌrwɑː sɒˈleɪ/noun
1An informal title of: Louis XIV, King of France from 1643 to 1715.
2A person who (or occasionally a thing which) has a dominance or pre-eminence comparable to that of Louis XIV.
Origin
Mid 19th century. From French roi soleil, informal title of Louis XIV of France, lit. ‘sun king’ from roi + soleil sun, with allusion to a heraldic device used by the king.