In the meantime after Potidaea was revolted, and whilst the Athenian fleet lay on the coast of Macedonia, the Corinthians, fearing what might become of the city and making the danger their own, sent unto it, both of their own city and of other Peloponnesians which they hired, to the number of sixteen hundred men of arms and four hundred light armed. The charge of these was given to Aristeus the son of Adimantus, for whose sake most of the volunteers of Corinth went the voyage: for he had been ever a great favourer of the Potidaeans. And they arrived in Thrace after the revolt of Potidaea forty days. The news of the revolt of these cities was likewise quickly brought to the Athenian people, who, hearing withal of the forces sent unto them under Aristeus, sent forth against the places revolted two thousand men of arms and forty galleys under the conduct of Callias, the son of Calliades. These, coming first into Macedonia, found there the former thousand, who by this time had taken Therme and were now besieging the city of Pydna; and staying, helped for a while to besiege it with the rest. But shortly after they took composition and, having made a necessary league with Perdiccas (urged thereto by the affairs of Potidaea, and the arrival there of Aristeus), departed from Macedonia. Thence coming to Berrhoea, they attempted to take it; but when they could not do it, they turned back and marched towards Potidaea by land. They were of their own number three thousand men of arms, besides many of their confederates, and of Macedonians that had served with Philip and Pausanias, six hundred horsemen. And their galleys, seventy in number, sailing by them along the coast, by moderate journeys came in three days to Gigonus and there encamped. The Potidaeans and the Peloponnesians under Aristeus, in expectation of the coming of the Athenians, lay now encamped in the isthmus near unto Olynthus and had the market kept for them without the city. And the leading of the foot the confederates had assigned to Aristeus, and of the horse to Perdiccas; for he fell off again presently from the Athenians and, having left Iolaus governor in his place, took part with the Potidaeans. The purpose of Aristeus was to have the body of the army with himself within the isthmus and therewith to attend the coming on of the Athenians, and to have the Chalcideans and their confederates without the isthmus, and also the two hundred horse under Perdiccas, to stay in Olynthus, and when the Athenians were passed by, to come on their backs and to inclose the enemy betwixt them. But Callias the Athenian general, and the rest that were in commission with him, sent out before them their Macedonian horsemen and some few of their confederates to Olynthus to stop those within from making any sally from the town, and then dislodging marched on towards Potidaea. When they were come on as far as the isthmus and saw the enemy make ready to fight, they also did the like; and not long after they joined battle. That wing wherein was Aristeus himself with the chosen men of the Corinthians and others put to flight that part of their enemies that stood opposite unto them and followed execution a great way. But the rest of the army of the Potidaeans and Peloponnesians were by the Athenians defeated and fled into the city. And Aristeus, when he came back from the execution, was in doubt what way to take, to Olynthus or to Potidaea. In the end he resolved of the shortest way, and with his soldiers about him ran as hard as he was able into Potidaea, and with much ado got in at the pier through the sea, cruelly shot at and with the loss of a few but the safety of the greatest part of his company. As soon as the battle began, they that should have seconded the Potidaeans from Olynthus (for it is at most but sixty furlongs off, and in sight) advanced a little way to have aided them; and the Macedonian horse opposed themselves likewise in order of battle to keep them back. But the Athenians having quickly gotten the victory, and the standards being taken down, they retired again, they of Olynthus into that city, and the Macedonian horsemen into the army of the Athenians. So that neither side had their cavalry at the battle. After the battle the Athenians erected a trophy and gave truce to the Potidaeans for the taking up of the bodies of their dead. Of the Potidaeans and their friends there died somewhat less than three hundred, and of the Athenians themselves one hundred and fifty, with Callias one of their commanders. Presently upon this the Athenians raised a wall before the city on the part toward the isthmus which they kept with a garrison, but the part to Pallene-ward they left unwalled. For they thought themselves too small a number both to keep a guard in the isthmus and withal to go over and fortify in Pallene, fearing lest the Potidaeans and their confederates should assault them when divided. When the people of Athens understood that Potidaea was unwalled on the part toward Pallene, not long after they sent thither sixteen hundred men of arms under the conduct of Phormio the son of Asopius, who arriving in Pallene left his galleys at Aphytis, and marching easily to Potidaea wasted the territory as he passed through. And when none came out to give him battle, he raised a wall before the city on that part also that looketh towards Pallene. Thus was Potidaea on both sides strongly besieged, and also from the sea by the Athenian galleys that came up and rode before it.