Grandson of the tyrant Clistene of Sycione, this Athenian statesman belongs to the Alcmaeonids, a large aristocratic family with a major place in the public life of Athens. Cleisthenes is elected first archon (political leader) in -525-524 but must fight to keep this power. Despite the decline of Peisistratus (tyrant of Athens), he was confronted with the aristocratic reactions of Isagoras, his political rival.
He reformed the city by establishing a distribution of citizens by territory, no longer by origin or social condition. It constitutes for this purpose ten tribes (basis of the representation of the magistracies), reorganized according to a territorial distribution. Institutions adapt to these tribes. The number of members of the boulê, divided into ten sections, is increased from 400 to 500, and the origin of a citizen is now defined by the name of his deme (territorial unit).
The democratization of institutions should encourage the involvement of citizens in the public life of the city. His work was completed by Ephialtes and Pericles.
565 BC. J.-C. - 492 BC. AD