The Ten New Tribes
Kleisthenes instituted a crucial reform, the reorganization of the citizenry into new administrative units called phylai (tribes). In his attempt to break up the aristocratic power structure, Kleisthenes abolished the use of the old Ionian tribes and created in their stead ten new ones. All citizens were assigned to one of these tribes, which were made up of members from each of the three geographical-and traditionally rivalries of Attica: plain, coast, and hills.
Political rights and many privileges depended on membership in one of the new tribes. Citizenship in Athens required prior enrollment in one of the tribes, and such membership was hereditary. A man served in the Boule (Senate) as a member of a tribe, and fought in the army -- where his life literally depended in part on the shield of the next man in line -- in a tribal contingent. Competitions in theatrical and athletic events were also carried out in tribal units.
Privileges included access to common grazing land reserved for members of a tribe, as well as access to sacrifices and feasts held in honor of tribal heroes. Fighting, feasting, competing, and enjoying the advantages of citizenship together forged new bonds of loyalty to fellow tribesmen, even though they were from different regions of Attica and belonged to different clans. Old allegiances to the local aristocratic families were correspondingly weakened, and the new tribal system should be seen as an essential feature of the Athenian democracy.
Having created the ten tribes, Kleisthenes then sent to Apollo's oracle at Delphi the names of one hundred early Athenian heroes, and the oracle chose ten, after whom the tribes were named. Hence the term eponymous, which means giving one's name to something. The Eponymous Heroes were Hippothoon, Antiochos, Aias, Leos, Erechtheus, Aigeus, Oineus, Akamas, Kekrops, and Pandion.
By the late 5th century a long base had been set up in the Agora to display statues of all ten heroes. This monument was one of the few allowed to stand within the limits of the open square, near the seat of government. The base became a public notice board: announcements concerning members of the tribes were hung on its front beneath the appropriate tribal hero. Thus, a member of the tribe of Leontis would find relevant notices beneath the statue of Leos: lists for military conscription, public honors, upcoming court appearances, and the like. More general announcements were also posted; in particular, legislation to be submitted to the Ekklesia (Assembly) was displayed at the Monument of the Eponymous Heroes for several days before the meeting so that citizens would have an opportunity to consider and discuss the proposals before voting. The base served as the prime source of official information within the city. Set in its prominent location, the Monument of the Eponymous Heroes was a crucial element in the dissemination of public information to the citizens of Athens and served also as the physical expression of the tribal system.