http://agathe.gr/democracy/overthrow_and_revolution.html
Overthrow and Revolution In 514 B.C. the tyrant Hipparchos was stabbed to death. The murder, actually the result of a love feud, was quickly deemed a political act of assassination and the perpetrators, ... The murder, actually the result of a love feud, was quickly deemed a political act of assassination and the perpetrators, Harmodios and Aristogeiton, were proclaimed heroes and tyrannicides. Several years after the deed they were honored with statues set up in the middle of the Agora. ... Herodotus regards them as more significant than the tyrannicides in bringing an end to the Peisistratid tyranny: Indeed, in my judgement it was the Alkmaeonidai much more than Harmodios and Aristogeiton who liberated Athens; for the latter two by their murder of Hipparchos merely exasperated the remaining members of the clan, without in any way checking their despotism, while the Alkmaeonidai did, in plain fact, actually bring about the liberation.