History of the Peloponnesian War

“And when the ships of the King arrive, the ships of the Lacedaemonians and their allies and those of the King shall wage war in common, according as it may seem best to Tissaphernes and to the Lacedaemonians and their allies. And if they wish to end the war with the Athenians, it shall be ended on the same footing for both.”

Such was the treaty they made. After this Tissaphernes set about preparing to bring the Phoenician ships, as had been agreed, and to carry out all the other things he had promised; and he wished it to be evident that at all events he was making preparations.

When the winter was now ending the Boeotians took Oropus, where the Athenians had a garrison, by treachery. And they had the cooperation of some men of Eretria and of Oropus itself who were plotting for the revolt of Euboea. For since the place is opposite Eretria, it was impossible, while the Athenians held it, that it should not injure greatly both Eretria and Euboea in general.