What two political revolutions occurred during the Classical period?

During the Classical period, two significant political revolutions were the Athenian democracy's establishment in ancient Greece and the Roman Republic's formation. The Athenian revolution transformed governance by introducing a direct democracy, allowing citizens to participate in decision-making. Meanwhile, the Roman Republic emerged as a response to monarchical rule, emphasizing a system of checks and balances through elected representatives and institutions. Both revolutions significantly influenced later political thought and systems.