History of the Peloponnesian War

At the very commencement of the following summer, the Boeotians seized on Heraclea, when it was miserably reduced after the battle, and sent away Hegesippidas the Lacedaemonian, on the charge of governing it ill. They occupied the place through fear that, while the Lacedaemonians were distracted with the affairs of the Peloponnese, the Athenians might take it. The Lacedaemonians, however, were offended with them for what they had done.

The same summer, Alcibiades son of Clinias, being one of the generals at Athens, having the co-operation of the Argives and the allies, went into the Peloponnese with a few Athenian heavy-armed and bowmen; and taking with him some of the allies in those parts, both proceeded to settle in concert with them other matters connected with the alliance, marching about the Peloponnese with his troops, and persuaded the Patreans to carry their walls down to the sea; intending also himself to build a fort beside the Achaean Rhium. But the Corinthians and Sicyonians, and all to whose injury it would have been built, came against him, and prevented his doing it.