Wikipedia
The Bacchiadae (Ancient Greek: Βακχιάδαι Bakkhiadai), a tightly-knit Doric clan, were the ruling family of archaic Corinth in the eighth and seventh centuries BCE, a period of Corinthian cultural power.
Corinth had been a backwater in eighth-century Greece. In 747 BCE (a traditional date) an aristocratic revolution ousted the Bacchiad kings of Corinth, when the royal clan of Bacchiadae, numbering perhaps a couple of hundred adult males and claiming descent from the Dorian hero Heracles through the seven sons and three daughters of a legendary king Bacchis, took power from the last king, Telestes. Practicising strict endogamy which kept clan outlines within a distinct extended oikos, they dispensed with kingship and ruled as a group, governing the city by electing annually a prytanis who held the kingly position for his brief term, no doubt a council (though none is specifically documented in the scant literary materials) and a polemarchos to head the army.
In 657 BCE the Bacchiadae were expelled in turn by the tyrant Cypselus, who had been polemarch. The exiled Bacchiadae fled to Corcyra but also to Sparta and west, traditionally to found Syracuse in Sicily, and to Etruria, where Demaratus installed himself at Tarquinia, founding a dynasty of Etruscan kings. The royal line of the Lynkestis of Macedon was also of Bacchiad descent. The foundation myths of Corcyra, Syracuse, and Megara Hyblaea contain considerable detail about the Bacchiadae and the expeditions of the Bacchiad Archias of Corinth, legendary founder of Syracuse in 734/33 BCE, and Philolaos, lover of Diocles of Corinth, victor at Olympia in 728 BCE and a nomothete (lawgiver) of Thebes.