The same summer and simultaneously with the expedition against Plataea, the Athenians marched with two thousand heavy infantry and two hundred horse against the Chalcidians in the direction of Thrace and the Bottiaeans, just as the corn was getting ripe, under the command of Xenophon, son of Euripides, with two colleagues. Arriving before Spartolus in Bottiaea, they destroyed the corn and had some hopes of the city coming over through the intrigues of a faction within. But those of a different way of thinking had sent to Olynthus;and a garrison of heavy infantry and other troops arrived accordingly.

These issuing from Spartolus were engaged by the Athenians in front of the town: the Chalcidian heavy infantry, and some auxiliaries with them, were beaten and retreated into Spartolus; but the Chalcidian horse and light troops defeated the horse and light troops of the Athenians. The Chalcidians had already a few targeteers from Crusis, and presently after the battle were joined by some others from Olynthus; upon seeing whom the light troops from Spartolus, emboldened by this accession and by their previous success, with the help of the Chalcidian horse and the reinforcement just arrived again attacked the Athenians, who retired upon the two divisions which they had left with their baggage. Whenever the Athenians advanced, their adversary gave way, pressing them with missiles the instant they began to retire. The Chalcidian horse also, riding up and charging them just as they pleased, at last caused a panic amongst them and routed and pursued them to a great distance. The Athenians took refuge in Potidaea, and afterwards recovered their dead under truce, and returned to Athens with the remnant of their army; four hundred and thirty men and all the generals having fallen. The Chalcidians and Bottiaeans set up a trophy, took up their dead, and dispersed to their several cities.

The same summer, not long after this, the Ambraciots and Chaonians, being desirous of reducing the whole of Acarnania and detaching it from Athens, persuaded the Lacedaemonians to equip a fleet from their confederacy and send a thousand heavy infantry to Acarnania, representing that, if a combined movement were made by land and sea, the coast Acarnanians would be unable to march, and the conquest of Zacynthus and Cephallenia easily following on the possession of Acarnania, the cruise round Peloponnese would be no longer so convenient for the Athenians. Besides which there was a hope of taking Naupactus. The Lacedaemonians accordingly at once sent off a few vessels with Cnemus, who was still high admiral, and the heavy infantry on board; and sent round orders for the fleet to equip as quickly as possible and sail to Leucas. The Corinthians were the most forward in the business; the Ambraciots being a colony of theirs.

While the ships from Corinth, Sicyon, and the neighbourhood were getting ready, and those from Leucas, Anactorium, and Ambracia, which had arrived before, were walting for them at Leucas, Cnemus and his thousand heavy infantry had run into the gulf, giving the slip to Phormio, the commander of the Athenian squadron stationed off Naupactus, and began at once to prepare for the land expedition. The Hellenic troops with him consisted of the Ambraciots, Leucadians, and Anactorians, and the thousand Peloponnesians with whom he came;the barbarian of a thousand Chaonians, who, belonging to a nation that has no king, were led by Photys and Nicanor, the two members of the royal family to whom the chieftainship for that year had been confided. With the Chaonians came also some Thesprotians, like them without a king, some Molossians and Atintanians led by Sabylinthus, the guardian of King Tharyps who was still a minor, and some Paravaeans, under their king Oroedus, accompanied by a thousand Orestians, subjects of King Antichus and placed by him under the command of Oroedus. There were also a thousand Macedonians sent by Perdiccas without the knowledge of the Athenians, but they arrived too late. With this force Cnemus set out, without waiting for the fleet from Corinth. Passing through the territory of Amphilochian Argos, and sacking the open village of Limnaea, they advanced to Stratus the Acarnanian capital; this once taken, the rest of the country, they felt convinced, would speedily follow.