In the early Roman Republic the head of government was divided between two annually elected Consuls in order to keep the government weak, as in the United States. However, in times of emergency the Romans recognized that a single leader would be needed so that in times of great need a single Dictator as military commander could be appointed for a limited period of 6 months. At the time of the empire Augustus assumed it as one of his many offices.

Benito Mussolini used this example to justify his seizure of power in Italy in 1921. However, he didn't resign after 6 months. Nor did he show what the emergency was.

In the 20th century the term dictator was used for all such people who seized power and ruled without democracy.