History of the Peloponnesian War

But though the decision was made it was impossible for them to take up arms at once, as they were unprepared; it was determined, however, that the several states should make the fitting preparations and that there should be no delay. Nevertheless, in providing themselves with what was needed there was spent, not indeed a full year, but somewhat less, before they invaded Attica and took up the war openly.

During this interval they kept sending embassies to the Athenians and making complaints, that they might have as good a pretext as possible for making war, in case the Athenians should refuse to consider them.

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.

Now Cylon consulted the oracle at Delphi, and the god in answer told him to seize the Acropolis of Athens "at the greatest festival of Zeus."