History of the Peloponnesian War

Aristeus, seeing the city enclosed on every side and without hope of safety save what might come from Peloponnesus or some other unexpected way, gave advice to all but five hundred, taking the opportunity of a wind, to go out by sea that the provision might the longer hold out for the rest, and of them that should remain within offered himself to be one.

But when his counsel took not place, being desirous to settle their business and make the best of their affairs abroad, he got out by sea unseen of the Athenian guard, and staying amongst the Chalcideans, amongst other actions of the war, laid an ambush before Sermylius and slew many of that city and solicited the sending of aid from Peloponnesus. And Phormio, after the siege laid to Potidaea, having with him his sixteen hundred men of arms, wasted the territory of the Chalcideans and Bottiaeans, and some small towns he took in.