History of the Peloponnesian War

Moreover, the Argives sent ambassadors to the Athenians, commanding them to evacuate their fortress in Epidaurus. They therefore, seeing themselves to be but few against many who joined in garrisoning it, sent Demosthenes to lead their men out of it; who having arrived, and instituted, by way of pretext, a gymnastic contest outside the fortress, when the rest of the garrison had gone out, shut the gates upon them. Afterwards, having renewed their treaty with the Epidaurians, the Athenians by themselves gave up the fortress.