History of the Peloponnesian War

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;