History of the Peloponnesian War

And of the Peloponnesian garrison a few at first resisted, and defended themselves, and some of them were killed; but the greater part took to flight, being terrified in consequence of the enemy having attacked them by night, and the Megarean traitors fighting against them; and thinking that all the Megareans had betrayed them.

For it happened that the Athenian herald had of his own accord proclaimed, that whoever of the Megareans wished, should go and pile his arms with the Athenians. So when they heard that, they stayed no longer; but thinking that they were certainly the objects of a common attack, fled for refuge to Nisaea.

In the morning, when the walls were now taken, and the Megareans in the city were in confusion, those who had negotiated with the Athenians, and others with them, viz. the popular party who were privy to the measure, said that they ought to throw open the gates, and march out to battle. It had been arranged by them, that when the gates were opened, the Athenians should rush in;