How was tyranny used in ancient Greece?

Tyrants were generaally wealthy landowners who were brought to power by the lower classes who had become tired of being held down and exploited by the oligarchs (small number of aristocrats) ruling the city-states. The tyrant was put in sole charge on the understanding that he ruled to the general good. They were vilified by those who had been replaced and today the Word has a bad meaning. To the majority of people who got a fair deal from them they were a godsend.