The word for today is…
despot (noun) – 1. A ruler with absolute power.
2. A person who wields power oppressively; a tyrant.
3. (a) A Byzantine emperor or prince.
(b) An Eastern Orthodox bishop or patriarch.
Source : The Free Dictionary
Etymology : In his 1755 dictionary, Samuel Johnson said of despot, “the word is not in use, except as applied to some Dacian prince; as the despot of Servia.” Indeed at that time, the word was mainly used to identify some very specific rulers or religious officials, and the title was an honorable one: it comes from a Greek word meaning “lord” or “master” and was originally applied to deities. That situation changed toward the end of the century, perhaps because French Revolutionists, who were said to have been “very liberal in conferring this title,” considered all sovereigns to be tyrannical. When democracy became all the rage, despot came to be used most often for any ruler who wielded absolute and often contemptuous and oppressive power.
