The city of Athens during the classical period of ancient Greece was the major urban centre of the notable polis (city-state) of the same name, located in Attica, Greece, leading the Delian League in the Peloponnesian War against Sparta and the Peloponnesian League. Athenian democracy was established in 508 BC under Cleisthenes following the tyranny of Isagoras. This system remained remarkably stable, and with a few brief interruptions remained in place for 180 years, until 322 BC. The peak of Athenian hegemony was achieved in the 440s to 430s BC, known as the Age of Pericles.

Classical Greece was a period of around 200 years in Ancient Greece, marked by much of the eastern Aegean and northern regions of Greek culture gaining increased autonomy from the Persian Empire; the peak flourishing of democratic Athens; the First and Second Peloponnesian Wars; the Spartan and then Theban hegemonies; and the expansion of Macedonia under Philip II. Much of the early defining mathematics, science, artistic thought, theatre, literature, philosophy, and politics of Western civilization derives from this period of Greek history, which had a powerful influence on the later Roman Empire. Part of the broader era of classical antiquity, the classical Greek era ended after Philip II's unification of most of the Greek world against the common enemy of the Persian Empire, which was conquered within 13 years during the wars of Alexander the Great, Philip's son.