History of the Peloponnesian War

The same summer likewise Demosthenes, general of the Athenians, with forty galleys, presently after his departure out of Megaris, sailed to Naupactus.

For certain men in the cities thereabouts, desiring to change the form of the Boeotian government and to turn it into a democracy according to the government of Athens, practised with him and Hippocrates to betray unto him the estates of Boeotia, induced thereunto principally by Ptoeodorus, a Theban outlaw; and they ordered the design thus:

Some had undertaken to deliver up Siphae (Siphae is a city of the territory of Thespiae, standing upon the seaside in the Crissaean gulf); and Chaeroneia, which was a town that paid duties to Orchomenus (called heretofore Orchomenus in Minyeia, but now Orchomenus in Boeotia), some others of Orchomenus were to surrender into their hands. And the Orchomenian outlaws had a principal hand in this and were hiring soldiers to that end out of Peloponnesus. This Chaeroneia is the utmost town of Boeotia towards Phanotis in the country of Phocis; and some Phoceans also dwelt in it.

[On the other side], the Athenians were to seize on Delium, a place consecrated to Apollo in the territory of Tanagra, on the part toward Euboea. All this ought to have been done together upon a day appointed, to the end that the Boeotians might not oppose them with their forces united, but might be troubled every one to defend his own.

And if the attempt succeeded, and that they once fortified Delium, they easily hoped, though no change followed in the state of the Boeotians for the present, yet being possessed of those places, and by that means continually fetching in prey out of the country, because there was for every one a place at hand to retire unto, that it could not stand long at a stay; but that the Athenians joining with such of them as rebelled, and the Boeotians not having their forces united, they might in time order the state to their own liking. Thus was the plot laid.