History of the Peloponnesian War

This was taken heavily by Harmodius; but Aristogeiton, for his sake, was far more exasperated than he. Whereupon, with the rest of the conspirators, he made all things ready for the execution of the design. Only they were to stay the time of the holiday called the Great Panathenaea, upon which day only such citizens as lead the procession might, without suspicion, be armed in good number. And they were to begin the fact themselves; but the rest were to help them against the halberdiers.

Now the conspirators, for their better security, were not many; for they hoped that such also as were not privy to it, if they saw it once undertaken, being upon this occasion armed, would assist in the recovery of their own liberty.

When this holiday was come, Hippias was gone out of the city into the place called Cerameicum with his guard of halberdiers, and was ordering the procession how it was to go. And Harmodius and Aristogeiton, with each of them a dagger, proceeded to the fact.

But when they saw one of the conspirators familiarly talking with Hippias (for Hippias was very affable to all men), they were afraid and believed that they were discovered and must presently have been apprehended.