History of the Peloponnesian War

But the Megarean factions were afraid, on the one side, that he might introduce the exiles, and expel them; on the other, that the popular party, through fear of this very thing, might attack them, and so the city be ruined by their fighting with each other, while the Athenians were close at hand in ambush against them; and therefore they did not receive him, but both parties determined to remain quiet, and wait to see the result.

For each side expected that a battle would be fought between the Athenians and those who had come to relieve the place, and that so it would be safer for themselves to go over to the side they favoured, if it were victorious. When therefore Brasidas did not prevail on them, he returned again to the rest of the army.

In the morning the Boeotians joined them, having indeed purposed, even before Brasidas sent to them, to march to the relief of Megara, considering the danger to affect themselves, and being already in full force at Plataea; but when the messenger reached them, they felt much more confidence, and after despatching two thousand two hundred heavy-armed, and six hundred cavalry, they returned again with the main force.

When the whole army was now come, amounting to no less than six thousand heavy-armed, and when the Athenian heavy-armed were formed in line about Nisaea at the shore, but their light-armed were dispersed over the plain; the Boeotian horse fell upon the light-armed, and drove them to the sea, while they were not expecting it; for before this no succours had yet come to the Megareans from any quarter.