Athens responded very differently to the social problems caused by an expanding population.  In 621 B.C., Draco published the first code of law. It was harsh, but included the idea that the law belonged to the people.  Despite this, Athens was governed oppressively by its aristocracy.  Solon, an Athenian aristocrat and poet, recognized how difficult the situation had become and called for reform.  His words were heeded and he was made chief magistrate of Athens.  He freed all those persons enslaved for debt and reorganized the political system into a more democratic form.  When Solon completed his reforms, he went into exile so as not to become a tyrant.
In 546 B.C.,  Pisistratus, an exiled aristocrat, came to power.  Under his rule, Athens prospered.  However, when his son succeeded him, a rebellion erupted.  Cleisthenes introduced wide ranging reforms.  These reforms  were based on the principle that all citizens were sovereign.  Every citizen was expected to participate in the process of governing.  There was an assembly made up of all male citizens.  They had the final word in Athens' decision-making.