History of the Peloponnesian War

As for Aristeus, now that Potidaea was cut off by the blockade and he had no hope of saving it unless help should come from the Peloponnesus or something else should happen beyond his expectation, he advised all the garrison except five hundred men to wait for a wind and sail out of the harbour, that the food might hold out longer, and he himself was ready to be one of those who should remain. But since he could not gain their consent, wishing to do the next best thing and to provide that their affairs outside should be put into the best possible condition, he sailed out, unobserved by the Athenian guard.

He then remained among the Chalcidians, whom he assisted generally in carrying on the war, and especially by destroying a large force of Sermylians, whom he ambushed near their city; and meanwhile he kept up negotiations with the Peloponnesians to see if some aid could not be obtained. Phormio, however, after the investment of Potidaea was complete, took his sixteen hundred troops and ravaged Chalcidice and Bottice; and he also captured some towns.