History of the Peloponnesian War

In the first place the Lacedaemonians sent ambassadors, and ordered the Athenians to drive out the pollution of the goddess; which pollution was of the following nature.

There was one Cylon, a man who had conquered at the Olympic games, an Athenian of the olden time, both noble and powerful; he had married a daughter of Theagenes, a Megarean, who at that time was tyrant of Megara.

Now when Cylon was consulting the oracle at Delphi, the god told him to seize on the Acropolis of the Athenians during the greatest feast of Jupiter.

So having received a force from Theagenes, and persuaded his friends to it, when the Olympic festival in the Peloponnese came on, he seized the Acropolis with a view to establishing a tyranny;