Tyranny in ancient Greece was not a phenomenon limited to any particular period. Tyrants could be found in power throughout Greece, ruling poleis from the 7th century BC right through to the 2nd century BC, when Roman domination effectively put an end to this form of government throughout the Hellenistic world. That said, the heyday of tyranny was undoubtedly the 7th and 6th centuries BC, and it is in this period, known as the Age of Tyrants, that large numbers of tyrannies arose, particularly in the Peloponnese.

The Age of Tyrants ended on the Greek mainland with the expulsion of the Peisistratidai in 510 BC, but it continued in other parts of the Greek world, particularly in the Greek cities of Sicily, where tyranny did not finally end until the removal of Dionysius II of Syracuse in 344 BC. In Asia Minor, tyranny survived the Persian conquest until the days of the Roman conquest.

The governments of the majority of the Greek states in the Archaic and Classical periods were in the hands of local aristocrats, and it is a modern preoccupation with the Athenian democracy or Sparta's unique system that has tended to obscure this fact. Oligarchy was the norm, and political power derived from wealth and birth. As the wealth of city states grew, so, too, did the number of citizens who, despite personal wealth, found themselves outside the very limited aristocratic elite that conspired to maintain the political power of the few. In today's modern world every political regime, even the most authoritarian or repressive, describes itself as democracy or a democratic people's republic. The concept of rule by the people, on behalf of the people, has come to be accepted as the norm, and very few would overtly espouse the cause of dictatorship, absolute monarchy or oligarchy as the most desirable political system upon which to base the government of any country. It is also generally accepted that democracy, as a political ideology, began in Greece, specifically in Athens, in the seventh century BC and reached its zenith in the fifth century under the leadership of Pericles. Dating an exact starting point is impossible, but at the beginning of the seventh century BC Solon inaugurated a series of reforms that began the movement away from rule by individuals, or tyrants, and by the end of that century the reforms of Cleisthenes provided the basis of the Athenian democratic system that culminated in the radical institutions introduced by Ephialtes and Pericles in the fifth century.