=121.= The Athenians had rightly judged the immediateness of the danger. Scarcely was their answer received when the Persian general was in motion, and advanced by rapid marches to the borders of Attica. He was re-enforced at every halt by northern Greeks, moved either by terror of his power or by long-standing jealousies against the members of the League. The Attic territory was utterly desolate and Athens a second time deserted. Taking possession of that city, Mardonius dispatched a Greek messenger to Salamis, repeating his former propositions, which were as instantly rejected as before.
The Athenians were a second time homeless, and, for the moment, standing alone against the enemies of Greece. The Spartans were engaged in some long-continued solemnities—perhaps the funeral of their regent, Cleom´brotus—and allowed the Athenian messengers to wait ten days for an answer. Not until the indignant envoys had threatened to make terms with Mardonius and leave Sparta to her fate, did the ephors bestir themselves, but then it was with true Spartan energy and dispatch. Five thousand Spartans and 35,000 slaves were sent, under the command of Pausanias, the new regent, to whom the ephors added a guard of 5,000 heavy-armed Laconians.
=122.= Hearing of the advance of the Spartans, the Persian thought best to retreat. He again set fire to Athens, leveled to the ground whatever remained of its walls and temples, and retired into Bœotia. Here he arranged his camp on a branch of the Asopus, not far from the city of Platæa. The Spartans followed, having been joined at the isthmus by the Peloponnesian allies, and, at Eleusis, by the Athenians. The Greek forces occupied the lower slopes of Mount Cithæron, with the river before them, separating them from the Persians.
=123.= BATTLE OF ERYTHRÆ. The battle was opened by the Persian cavalry, commanded by Masis´tius, the most illustrious general in the army, except Mardonius. His magnificent person, clad in complete scale-armor of gold and burnished brass, was conspicuous upon the battle-field; and his horsemen, then the most famous in the world for their skill and bravery, severely harassed the Megarians, who were posted on the open plain. Olym´piodo´rus with a select body of Athenians went to their assistance, and Masistius spurred his Nisæan steed across the field to meet him. In the sharp combat which followed, the Persian was unhorsed, and as he lay along the ground was assailed by a swarm of enemies. The heavy armor, which prevented his rising, protected him from their weapons, until, at length, an opening in his visor allowed a lance to reach his brain. His death decided the fate of the battle.