History of the Peloponnesian War

Then each of the Athenians, as he successively entered, proceeded against the wall.

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.