Classical Athens refers to the city of Athens from 508 to 322 BC. Athenian democracy was established in 508 BC under Cleisthenes, after the tyranny of the Peistratids and the rule of Isagoras. This system remained remarkably stable, and with a few brief interruptions remained in place for 180 years, until 322 BC. Athens was one of the most powerful cities in ancient times. It was important because there democracy developed.