History of the Peloponnesian War

They attacked their strong-hold and took it, but the men, having escaped in a body to a higher eminence, surrendered on condition of giving up their auxiliaries, and letting the Athenian people decide their own fate, after they had given up their arms. So the generals carried them across under truce to the island of Ptychia, to be kept in custody until they were sent to Athens;

with an understanding that if any one were caught running away, the treaty would be void in the case of all.