Plutarch, De Herodoti malignitate
Goodwin, Ed.

In his ninth and last book, having nothing left to vent his malice on but the Lacedaemonians and their glorious action against the barbarians at Plataea, he writes, that the Spartans at first feared lest the Athenians should suffer themselves to be persuaded by Mardonius to forsake the other Greeks; but that now, the Isthmus being fortified, they, supposing all to be safe at Peloponnesus, neglected and slighted the rest, feasting and making merry at home, and deluding and delaying the Athenian ambassadors.¹ How then did there go forth from Sparta to Plataea a thousand and five men, having every one of them with him seven Helots? Or how came it that, exposing themselves to so many dangers, they vanquished and overthrew so many thousand barbarians? Hear now his probable cause of it. ‘It happened,’ says he, ‘that there was then at Sparta a certain stranger of Tegea, named Chileus, who had some friends amongst the Ephori, between whom and him there was mutual hospitality. He then persuaded them to send forth the army, telling them that the fortification on the Isthmus, by which they had fenced in Peloponnesus, would be of no avail if the Athenians joined themselves with Mardonius.’ ² This counsel then drew Pausanias with his army to Plataea; but if any private business had kept that Chileus at Tegea, Greece had never been victorious.