Hipparchus (son of Peisistratos)
He was said by some Greek authors to have been the tyrant of Athens along with his brother Hippias after Peisistratos died, about 528/7 BC. The word tyrant literally means "one who takes power by force", as opposed to a ruler who inherited a monarchy or was chosen in some way. It carried no pejorative connotation during the Archaic and early Classical periods. In actuality, according to Thucydides, Hippias was the only 'tyrant'. Both Hipparchus and Hippias enjoyed the popular support of the people. Hipparchus was a patron of the arts; it was Hipparchus who invited Simonides of Ceos to Athens.
In 514 BC Hipparchus was assassinated 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. Not only did Harmodius reject him, but humiliated him by telling Aristogeiton of his advances. Hipparchus then invited Harmodius's sister to participate in the Panathenaic Festival as kanephoros only to publicly disqualify her on the grounds that she was not a virgin. Harmodius and Aristogeiton then organised a revolt for the Panathenaic Games but they panicked and attacked too early. Although they killed Hipparchus, Harmodius was killed by his bodyguard and Aristogeiton was arrested, tortured and later killed. According to Thucydides, Hippias ordered the Greeks to lay down their ceremonial arms and then had them searched, arresting any found with concealed weapons. This was later denied by Aristotle, who said that this story was created by the democratic government in order to impress upon the people how much of a tyrant Hippias was. Aristotle also mentions that Aristogeiton was tortured in order to give the names of the conspirators in the plot. Enraged that Hippias hadn't killed him, Aristogiton offered more names to Hippias in exchange for his hand in pledge. When Hippias put his hand on Aristogiton's, Aristogiton berated him for giving his hand to his brother's murderer - at which point Hippias stabbed Aristogeiton in rage.
After the assassination, Hippias became a bitter and cruel tyrant, and was overthrown a few years later in 510 by the Spartan king Cleomenes I. Modern scholarship generally ascribes the tradition that Hipparchus was himself a cruel tyrant to the cult of Harmodius and Aristogeiton established after the downfall of the tyranny.