Battle of Plataea

Plataea, in Boeotia in central Greece, gave its name to the last great land battle of the second Persian invasion of Greece, fought in August 479 BC. An alliance of Greek city-states under the Spartan regent Pausanias destroyed the army that Xerxes had left behind under his general Mardonius, who was killed. Together with the naval victory at Mycale, it ended Persian attempts to conquer mainland Greece and is widely seen as a turning point in the Greco-Persian Wars.

Xerxes I invaded Greece in 480 BC. His army forced the pass at Thermopylae, burned Plataea and Thespiae, and occupied Athens, which had been evacuated. But the defeat of the Persian fleet at Salamis later that year led the king to return to Asia with part of his forces, leaving Mardonius to finish the conquest. Mardonius wintered in Thessaly and tried to win Athens over with offers of peace. When these failed he reoccupied the city in 479 BC, and the Athenians threatened to come to terms unless Sparta sent help. Sparta at last marched, with 5,000 full citizens among a much larger force.

The ancient figures are not reliable. Herodotus credits the Persians with 300,000 men plus about 50,000 Greek allies, and the later writer Diodorus gives 500,000. Modern historians generally estimate the Persian army at somewhere between 70,000 and 120,000, including Greek contingents from Thebes, Thessaly and Macedon, with a strong cavalry arm. The Greek army, drawn from Sparta, Athens, Corinth, Tegea, Megara and many smaller states, is usually put at roughly 75,000 to 85,000, including about 38,700 heavy infantry.

Mardonius pulled back into Boeotia and built a fortified camp on the north bank of the Asopos river, on open ground that suited his horsemen. The Greeks crossed Mount Cithaeron and stayed on the higher slopes. Persian cavalry harassed them, but their commander Masistius was killed in one attack, which raised Greek morale enough for them to move closer to the river. For days neither side would cross, and both sides' seers reportedly warned against attacking. Persian cavalry then cut the Greek supply columns and blocked the spring the Greeks depended on for water.

With their position untenable, the Greeks tried to withdraw by night to better ground nearer Plataea. The move went badly: the centre lost its way, and the Spartan right wing was held up when one of its officers refused to retreat. At dawn Mardonius saw the Greeks scattered and ordered a pursuit. The Persian infantry formed a shield wall and shot volleys of arrows into the Spartans and Tegeans. When the Greeks finally charged, they pressed into the shield wall and gained the upper hand in the close fighting. Mardonius fell, and his guard and then the rest of his army gave way. The Athenians meanwhile defeated the Thebans fighting on the Persian side. The Greeks stormed the Persian camp and killed large numbers inside. One Persian commander, Artabazos, had kept his corps out of the fight and led it back to Asia.

Casualty figures are equally uncertain. Herodotus claims 257,000 Persian dead, while modern estimates of Persian losses run from about 50,000 to 90,000. Ancient figures for the Greek dead range from 159 (Herodotus) and 1,360 (Plutarch) to more than 10,000 (Ephorus and Diodorus).

According to Herodotus, the Greek fleet won at Mycale, in Asia Minor, on the same day. The Greeks then besieged Thebes and executed leaders who had sided with Persia, and Athens went on to take Sestos on the Hellespont. Sparta withdrew from the war, leaving Athens to lead the fight against Persia in the Aegean. The spoils funded monuments at Delphi and elsewhere. Plutarch reports that Alexander the Great later saw Plataea as a step on the road to his own conquest of Persia.

Our 500 BCE map shows the Achaemenid Empire and the Greek states on the eve of the invasions; the battlefield lies in modern Greece.