The Athenian democracy was established in 508 BC under Cleisthenes, after the assassination of Hipparchus had hardened his brother Hippias into a worse tyrant and after a Spartan force had finally driven him out. The reforms replaced the four old Ionic tribes with ten new ones, named after legendary heroes and built without class distinctions. Each tribe sent fifty members, chosen by lot, to the Boule - the council of five hundred that ran the city day-to-day. The Assembly, the Ecclesia, was open to every adult male citizen and acted as both legislature and supreme court. Most public offices were filled by drawing names from an urn. Only the ten generals, the strategoi, were elected, on the principle that you might trust the gods to give you a competent magistrate but you wanted to choose your own commander. The system was strange, fragile, and remarkably durable: with brief interruptions during the oligarchic coup of 411 and the rule of the Thirty Tyrants in 404, it lasted 180 years.

It is necessary to be honest about the limits. Athenian democracy meant adult male citizens, perhaps thirty thousand of them in a city whose total population was four times that. Women had no political role and were largely confined to household life. Resident foreigners, the metics, paid taxes and served in the army but could not vote. And the prosperity of classical Athens depended in part on the silver mines of Laurion in southeastern Attica, where tens of thousands of enslaved people - many of them captured in Athenian wars or trafficked through Aegean markets - dug ore in dangerous tunnels for absentee owners. Themistocles convinced the Athenians to spend the silver building a fleet, and that fleet won at Salamis. The democracy that produced Pericles, Sophocles, and the Parthenon was funded, in part, by people who had no say in any of it. The classical achievement and that injustice are not separable, and any honest account has to hold them together.

Pericles was elected strategos in 445 BC and reelected every year until his death in 429. During those sixteen years he used the tribute paid by allied cities of the Delian League - originally collected to defend Greece against further Persian attacks - to build the monuments that still define Athens from the air. The Parthenon went up between 447 and 432, decorated with sculpture so accomplished that the Romans were still copying it five hundred years later. The Erechtheion, with its caryatid porch of six robed women holding up the roof, was finished after his death. The Propylaia framed the western entrance to the Acropolis. Down in the lower city, the Theatre of Dionysus on the southeast slope hosted the festivals where Aeschylus, Sophocles, Euripides, and Aristophanes premiered the plays that founded a literature. Pericles called the city an "education for Hellas." Thucydides, who heard him say it, recorded the line.

The walls themselves told the strategy. Athens proper sat about thirty stadia from the sea, on the southwest slope of Mount Lycabettus. To turn the city into an island that could not be starved out, Themistocles, Conon, and Pericles built two parallel Long Walls running 7 km down to the harbor of Piraeus, with a third wall reaching to Phalerum on the east. While the walls held and the fleet sailed, Athens could outlast any land army. The Peloponnesian War tested the theory for twenty-seven years, from 431 to 404. Sparta eventually built its own navy, broke the seawall strategy, and forced Athens to surrender. The democracy was briefly overthrown by the Thirty Tyrants. In 403 it was restored by Thrasybulus, with an amnesty declared. Athens fought further wars - the Corinthian War, the Second Athenian League - but the long arc was downward. In 338, Philip II of Macedon defeated a Theban-Athenian alliance at Chaeronea, and the city's days as an independent power ended. Antipater dissolved the democratic government in 322 BC, after the Lamian War. Athens kept its libraries, its philosophers, and its plays, but it would not run itself again for two thousand years.