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 when the festival came on, Hippias with his bodyguard was outside the walls, in the place called the Cerameicus, arranging the order in which the several parts of the procession were to go forward; and Harmodius and Aristogeiton, who were ready with their daggers, stepped forward to put their scheme in effect.
But when they saw one of their accomplices talking familiarly with Hippias, who was accessible to all, they took fright, thinking that they had been informed upon and would in a moment be arrested.
So wishing first to take vengeance, if they could, upon the one who had aggrieved them and because of whom they were risking all, they rushed, just as they were, within the gates and came upon Hipparchus at the place called Leocorium.[*](The sanctuary of the daughters of Leos, an ancient Attic king, who in a famine were sacrificed for the state. It was in the Inner Cerameicus, near the temple of Apollo Patrous.) And at once falling upon him recklessly and as men will in extreme wrath, the one inflamed by jealousy, the other by insult, they smote and slew him.
Aristogeiton, indeed, escaped the guards for the moment, as the crowd ran together, but afterwards was caught and handled in no gentle manner; but Harmodius perished on the spot.
When the news was brought to Hippias in the Cerameicus, he went at once, not to the scene of action, but to the hoplites in the procession, before they, being some distance away, had become aware of what had happened, and, disguising his looks so as to betray nothing in regard to the calamity, pointed to a certain place and ordered them to go thither without their arms.
So they withdrew, thinking that he had something to say to them; while he, ordering the mercenaries to take up the arms of the others, immediately picked out those whom he held guilty, and anyone besides who was found with a dagger; for it was customary to march in the processions armed with shield and spear only.
It was in such wise, for an affront in love, that the plot of Harmodius and Aristogeiton was first conceived and their reckless attempt made under the influence of their momentary alarm.