Battle of Plataea (479 BC): The End of Xerxes' Invasion

The Battle of Plataea was fought in August 479 BC near the small city of Plataea in Boeotia, central Greece, between an alliance of Greek city-states led by Sparta and the Persian army left behind by King Xerxes. The Greek victory, in which the Persian commander Mardonius was killed, ended the second Persian invasion of Greece and was the largest land battle of the Greco-Persian Wars.

Background: Persia’s second invasion

In 480 BC Xerxes crossed the Hellespont with a vast army and fleet. The Greeks lost the pass at the Battle of Thermopylae, Athens was evacuated and burned, but the Greek fleet then won a decisive victory at the Battle of Salamis in September 480 BC.

Xerxes returned to Asia with part of his forces. He left his cousin and brother-in-law Mardonius in Greece with a picked army, which wintered in Thessaly. Mardonius still had a strong position: northern Greece, including Thebes and most of Boeotia, sided with Persia, and his cavalry was far superior to anything the Greeks could field.

In spring 479 BC Mardonius tried diplomacy first. Through Alexander I of Macedon he offered Athens generous terms, including rebuilding its temples, if it would change sides. The Athenians refused. Mardonius then reoccupied Athens in early summer and burned it a second time, while the Athenians again took refuge on Salamis and pressed Sparta to march.

The armies

The Spartans delayed, partly because of a religious festival, but finally sent out an exceptionally large force. Herodotus says 5,000 Spartan citizens marched, each with seven helots (state-owned serfs), together with 5,000 perioikoi (free non-citizens of Laconia). Allies from the Peloponnese, Athens, Megara, Plataea and elsewhere joined them.

Herodotus lists 38,700 hoplites (heavy infantry) and puts the whole Greek army, with light troops, at about 110,000. He gives the Persians 300,000 men plus around 50,000 Greek allies. Modern historians accept the Greek hoplite total as roughly plausible but reduce the Persian army sharply, usually to between about 70,000 and 120,000.

When the Greeks reached the Isthmus and crossed into Attica, Mardonius withdrew into Boeotia, where the ground suited his horsemen. He built a fortified camp of timber near the Asopus river and waited.

What happened

The Greeks first took up a position on the lower slopes of Mount Cithaeron near Erythrae. Persian cavalry attacked the Megarian contingent, and in the fighting the Persian cavalry commander Masistius was unhorsed and killed by a picked Athenian force supported by archers. Encouraged, the Greeks moved down to a second line closer to the Asopus, near a spring called Gargaphia.

A long stand-off followed, perhaps eleven or twelve days. Neither side wished to attack across the river: the seers of both armies reportedly found the omens favourable only for defence. Meanwhile Persian cavalry raided the Greek supply convoys coming over the Cithaeron passes and finally choked the Gargaphia spring, leaving the Greeks short of water and food.

Pausanias ordered a night withdrawal to a better position nearer Plataea. It went badly. The centre moved too far and ended up near the city, the Athenians waited, and one Spartan officer, Amompharetus, at first refused to retreat in the face of the enemy. At dawn the Greek army was strung out in three separate groups.

Mardonius saw an opportunity and attacked. His best Persian infantry fell on the Spartans and Tegeans, while his Boeotian and other Greek allies engaged the Athenians. The Persian infantry fought bravely behind a wall of wicker shields, but they were lightly armoured compared with hoplites. When Mardonius himself was killed, reportedly by a Spartan named Arimnestus, his troops broke and fled to the fortified camp.

The Athenians, after defeating the Thebans, joined the assault on the stockade. Once the wall was breached, the Greeks killed large numbers of the trapped soldiers. The Persian general Artabazus, who had disagreed with Mardonius, had already marched away with a large force, said to be 40,000 men, and led it back to Asia through Thessaly and Thrace.

Key people

• Pausanias: Spartan regent for the boy king Pleistarchus, son of Leonidas, and supreme Greek commander. He was later accused of arrogance and of plotting with Persia, and died in disgrace around 470 BC.
• Mardonius: Persian noble, son of Gobryas, who had urged the invasion of Greece. His death on the battlefield decided the day.
• Aristides: Athenian statesman known as “the Just”, who commanded the Athenian contingent of 8,000 hoplites.
• Artabazus: Persian commander who withdrew his corps intact and later served as a satrap in Anatolia.

Consequences

The Greeks took enormous booty from the Persian camp, including gold, silver and luxurious tents. A tenth was dedicated to the gods. At Delphi the allies set up a gold tripod on a bronze column of three intertwined snakes, inscribed with the names of the 31 states that had fought. Its remains, the Serpent Column, now stand in Istanbul.

The Greeks then besieged Thebes, which handed over its pro-Persian leaders; they were executed at Corinth. Plataea was declared sacred and inviolable, and a festival of freedom, the Eleutheria, was later held there in honour of the dead.

According to tradition, on the same day the Greek fleet destroyed the remaining Persian naval forces at the Battle of Mycale on the coast of Ionia. Persia never again sent an army into mainland Greece. Within a year Athens had become leader of a new naval alliance, the Delian League, which carried the war into the Aegean.

By the numbers

Herodotus’ casualty figures are widely regarded as unreliable: his Greek total is probably too low, and his claim that barely 3,000 of Mardonius’ men survived, apart from Artabazus’ corps, is certainly an exaggeration.

Myths and facts

A common claim is that Plataea was won by brilliant Greek generalship. In fact the battle grew out of a confused withdrawal, and the Greek army came close to being defeated in detail. It was the discipline and heavy armour of the Spartan and Tegean hoplites, and the death of Mardonius, that turned the crisis into victory.

Another claim is that all the Greeks fought against Persia. Many did not: Thebes and much of Boeotia, Thessaly and other states fought on the Persian side, and the Athenians spent most of the battle fighting fellow Greeks.

Timeline

• 480 BC, September: Greek naval victory at Salamis; Xerxes returns to Asia and leaves Mardonius in Greece.
• 479 BC, spring: Mardonius offers Athens an alliance through Alexander I of Macedon; Athens refuses.
• 479 BC, early summer: Mardonius reoccupies and burns Athens.
• 479 BC, summer: The Spartan army marches; Mardonius withdraws into Boeotia and fortifies a camp on the Asopus.
• 479 BC, August: Skirmishes and death of Masistius, followed by a stand-off of about eleven or twelve days.
• 479 BC, August: Night withdrawal, Persian attack, death of Mardonius and storming of the Persian camp.
• 479 BC, August: Greek victory at Mycale in Ionia, traditionally on the same day.
• 479 BC, autumn: Siege of Thebes and execution of its pro-Persian leaders.

Why it matters

Plataea ended the most serious attempt by the Persian Empire to conquer Greece. The independence of the Greek city-states, including the democratic Athens of the following decades, rested on this victory. For Herodotus, whose account is our main source, Plataea and Mycale together closed the great war between Greeks and Persians that his history set out to explain.