Hipparkhos (or Hipparchus) (d. 514 BCE) was a member of the Athenian ruling class, and a son of the late tyrant Peisistratos. Hipparkhos was assassinated by Harmodios and Aristogeiton after a series of tit-for-tat insults between the former and Hipparkhos. While the two had sought to overthrow the tyranny of Hipparkhos's brother, Hippias, they were ultimately unsuccessful. However, after Hippias was overthrown a few years later, Harmodios and Aristogeiton came to be viewed as martyrs to democracy, and Hipparkhos was placed in the role of "tyrant".