From The Art and Popular Culture Encyclopedia
Dictator is originally the title of a magistrate in ancient Rome appointed by the Senate to rule the state in times of emergency. In modern usage, it refers to an absolutist or autocratic ruler who assumes sole power over the state (though the term is normally not applied to an absolute monarch; see also Oliver Cromwell).
Modern dictators have usually come to power in times of emergency. Frequently they have seized power by coup, but some, most notably Benito Mussolini in Italy and Adolf Hitler in Germany achieved office as head of government by legal means (election or appointment), and once in office gained additional extraordinary powers. Mainly Latin American, Asian and African nations, especially Third World, have known many dictatorships, usually by military leaders at the head of a junta, either claiming to constitute a revolution or to reestablish order and stability.