History of the Peloponnesian War

Not long after, ambassadors came from Argos with the proposals that have been mentioned; whom the Boeotarchs sent back after assenting to their terms, and promising to send envoys to Argos on the question of the alliance.

In the mean time it was determined by the Boeotarchs, the Corinthians, the Megareans, and the ambassadors from Thrace, in the first place, to bind themselves by oaths to each other, that assuredly, when occasion offered, they would assist the party which needed it; and that they would carry on war with none, or make peace, without common assent; and that so the Boeotians and Megareans (for they had the same object before them) should then enter into treaty with the Argives.