Their fall was occasioned by the conspiracy of Harmodius and Aristogiton, who were attached to each other by a most intimate friendship. Harmodius having given offence to Hippias, the despot revenged himself by putting a public affront upon his sister. This indignity excited the resentment of the two friends, and they now resolved to slay the despots at the festival of the Great Panathenaea, when all the citizens were required to attend in arms. Having communicated their design to a few associates, the conspirators appeared armed at the appointed time like the rest of the citizens, but carrying concealed daggers besides. Harmodius and Aristogiton had planned to kill Hippias first as he was arranging the order of the procession outside the city, but, upon approaching the spot where he was standing, they were thunderstruck at beholding one of the conspirators in close conversation with the despot. Believing that they were betrayed, they rushed back into the city with their daggers hid in the myrtle boughs which they were to have carried in the procession, and killed Hipparchus. Harmodius was immediately cut down by the guards. Aristogiton died under the tortures to which he was subjected in order to compel him to disclose his accomplices. Hipparchus was assassinated in B.C. 514, the fourteenth year after the death of Pisistratus. From this time the character of the government became entirely changed. His brother's murder converted Hippias into a cruel and suspicious tyrant. He put to death numbers of the citizens, and raised large sums of money by extraordinary taxes. The Alcmaeonidae, who had lived in exile ever since the third and final restoration of Pisistratus to Athens, now began to form schemes to expel the tyrant. Clisthenes, the son of Megacles, who was the head of the family, secured the Delphian oracle by pecuniary presents to the Pythia, or priestess, henceforth, whenever the Spartans came to consult the oracle, the answer of the priestess was always the same, "Athens must be liberated." This order was so often repeated, that the Spartans at last resolved to obey. Cleomenes, king of Sparta, defeated the Thessalian allies of Hippias; and the tyrant, unable to meet his enemies in the field, took refuge in the Acropolis. Here he might have maintained himself in safety, had not his children been made prisoners as they were being secretly carried out of the country. To procure their restoration, he consented to quit Attics in the space of five days. He sailed to Asia, and took up his residence at Sigeum in the Troad, which his father had wrested from the Mytilenaeans in war.