Not all Greeks stood together to repel the invading Persian army in 480–479 B.C. Thebes, hostile toward Athens, allied itself with the Persians. Before the Battle at Plataea, in which the Persian general Mardonius was soundly defeated, the Thebans invited their Persian allies to a banquet—a story touchingly recounted by Herodotus in Histories 9.15–16 (translated by Robin Waterfield):

“While the Persians were busy with this building work, a Theban called Attaginus the son of Phrynon prepared a magnificent banquet and invited to it not only Mardonius himself, but also the fifty most eminent Persians, who all came in response to the invitation. The banquet was held in Thebes.

“I heard what follows from Thersander of Orchomenus, who was one of the most distinguished men of his home town. Thersander told me that he was one of the people invited by Attaginus to this banquet, along with fifty Thebans, and that rather than having the two sets of people—Persian and Theban—reclining on separate couches, Attaginus placed one of each on every couch. After the meal, while they were still drinking, the Persian who was sharing a couch with Thersander asked him in Greek where he was from. When he answered that he was from Orchomenus, the Persian said, ‘Since we’ve shared a table and poured a libation from the same cup, I want to leave you a record of my opinion. Then, with advance warning, you’ll be in a position to decide what to do to ensure your own safety. Look at these Persians here at the banquet, and consider also the army which we have left encamped on the river. Before much time has passed you’ll see few of them left alive.’

“The Persian was weeping as he spoke, Thersander said. He was astonished at his words and said to him, ‘Shouldn’t you be telling this to Mardonius and the next hightest-ranking Persians?’

“‘My friend,’ the Persian replied, ‘an event which has been decreed by the god cannot be averted by man, for no one is willing to believe even those who tell the truth. A great many Persians are well aware of what I’ve just said, but we follow our leaders because we have no choice. There’s no more terrible pain a man can endure than to see clearly and be able to do nothing.’

“This is what I was told by Thersander of Orchomenus, and he added that he lost no time in telling others the story—that is, that he did so before the battle of Plataea took place.”