History of the Peloponnesian War

The Potidaeans, on the other hand, sent envoys to Atlens, to see if they could persuade them not to take any harsh measures with reference to themselves; but envoys of theirs went also to Lacedaemon in the company of the Corinthians, with the object of having assistance ready to hand in case of need. From the Athenians, with whom they carried on protracted negotiation, they obtained no satisfactory result, but on the contrary the ships destined to attack Macedonia proceeded to sail against themselves as well, whereas the magistrates of the Lacedaemonians promised them to invade Attica if the Athenians went against Potidaea; so they seized this opportunity and revolted. entering into a formal alliance with the Chalcidians[*](i.e. the Chalcidians of Thrace.) and Bottiaeans.

Perdiccas at the same time per suaded the Chalcidians to abandon and pull dowr their cities on the sea-coast and settle inland at Olynthus, making there a single strong city; and he gave them, when they abandoned their cities, a part of his own territory of Mygdonia around Lake Bolbe to cultivate as long as they should be at war with the Athenians. And so they proceeded to dismantle their cities, move inland, and prepare for war.