History of the Peloponnesian War

Thucydides

Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.

And first the Lacedaemonian envoys bade the Athenians drive out the "curse of the goddess." The curse was as follows:

There was an Athenian in days of old named Cylon, a victor at Olympia, of noble birth and powerful; and he had married a daughter of Theagenes, a Megarian, who was at that time tyrant of Megara.