tyrant of the ancient Greek city of Sicyon. He belonged to the non-Dorian family of Orthagoras, who had established the tyranny in Sicyon with the support of the Ionian section of the inhabitants. Cleisthenes emphasized the destruction of Dorian predominance by giving ridiculous epithets to their tribal units, which from Hylleis, Dymanes, and Pamphyli become Hyatae (Swine-men), Choireatae (Pig-men), and Oneatae (Ass-men). He also attacked Dorian Argos and suppressed the Homeric rhapsodists who sang the exploits of Dorian heroes.

He championed the cause of the Delphic (Delphi) oracle against the town of Crisa in the Sacred War of c. 595–596 BC. Crisa was destroyed, and Delphi became one of the meeting places of the Amphictyonic League, or religious league of neighbouring states. The Pythian Games were reestablished with new magnificence, and Cleisthenes won the first chariot race in 582. He founded Pythian games at Sicyon and built a new Sicyonian treasury at Delphi. His power was so great that, when he offered his daughter Agariste in marriage, some of the most prominent Greeks sought the honour, which fell upon Megacles, the Alcmaeoid. The story of the rival suitors is told by Herodotus.