Autocrat

1. (n.) An absolute sovereign; a monarch who holds and exercises the powers of government by claim of absolute right, not subject to restriction; as, Autocrat of all the Russias (a title of the Czar).

2. (a.) One who rules with undisputed sway in any company or relation; a despot.

Thesaurus Entries

Simon Legree, absolute monarch, absolute ruler, all-powerful ruler, arrogator, autarch, caesar, commissar, czar, despot, dictator, disciplinarian, driver, duce, hard master, martinet, oligarch, oppressor, pharaoh, slave driver, stickler, tyrant, usurper, warlord