Autocrat

Au·to·crat

Autocrat

n.
  1. 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. One who rules with undisputed sway in any company or relation; a despot.
    The autocrat of the breakfast table.