Hipparchus (son of Peisistratos) in Wikipedia

Hipparchus or Hipparch (Ἵππαρχος) (d. 514 BCE) was a ruler of Athens. He was one of the sons of Peisistratos. Although he was said among Greeks to have been the tyrant of Athens along with his brother Hippias when Pisistratus died, about 527 BC, in actuality, according to Thucydides, Hippias was the tyrant. Hipparchus was a patron of the arts; and it was Hipparchus who invited Simonides of Ceos to Athens. In 514 BC Hipparchus was murdered by the Tyrannicides, Harmodius and Aristogeiton. This was apparently a personal dispute, according to Herodotus and Thucydides. Hipparchus had fallen in love with Harmodius, who was already the lover of Aristogeiton. When Harmodius rejected him, Hipparchus invited Harmodius's sister to participate in the Panathenaic Festival as kanephoros only to spurn her when she appeared in her finest, insinuating that she was not a virgin. As a result, Harmodius and Aristogeiton assassinated him. After the assassination, Hippias became a bitter and cruel tyrant, and was overthrown a few years later in 510 by the Spartan king Cleomenes. Modern scholarship generally ascribes the tradition that Hipparchus was a tyrant himself - as opposed to having a privileged position as the tyrant's brother - to the cult of Harmodius and Aristogeiton established after the revolution.