Soon after their victory over the Persians at the battle of Marathon in 490 B.C., the Athenians began the practice of ostracism, a form of election designed to curb the power of any rising tyrant. They were probably inspired at least in part by the fact that their old tyrant Hippias, who had been thrown out years before, accompanied the Persian fleet to Marathon, hoping to be reinstalled in power in Athens once again.

The procedure of ostracism was simple. Once a year the people would meet in the Agora and take a vote to determine if anyone was becoming too powerful and was in a position to establish a tyranny. If a simple majority voted yes, they met again in the Agora two months later. At this second meeting each citizen carried with him an ostrakon (potsherd) on which he had scratched the name of the person he wished ostracized. if at least 6,000 votes were cast, the man with the most votes lost and was exiled for ten years.

Ostrakon of Megakles (left), ostracized in 486 B.C. Max. dim.: 0.11 m. Athens, Agora Museum P 14490. Inscribed ΜΕΓΑΚΛΕΣ ΗΙΠΠΟΚΡΑΤΕΣ, Megakles son of Hippokrates. Aristotle reports the ostracism of Megakles son of Hippokrates, and goes on to say that "the Athenians continued for three years to ostracize the friends of the tyrants, on account of whom the law had been enacted" (Athenian Constitution 22). More than 4,000 ostraka bearing Megakles' name were found in one deposit in the Kerameikos (the potters' quarter of Athens) and have been associated with the ostracism of 486 B.C., although the rude comments that accompany his name on some of these ostraka concentrate on his morals rather than on his tyrannical tendencies.
Ostrakon of Xanthippos (right), ostracized in 484 B.C. Max. dim.: 0.073 m. Athens, Agora Museum P 6107. Inscribed: ΧΣΑΝΘΙΠΠΟΣ ΑΡΡΙΦΡΟΝΟΣ, Xanthippos son of Arriphron. Aristotle says that after three years of concentrating on ostracizing the friends of the tyrants, the Athenians "took to removing anyone else who seemed too powerful: the first man unconnected with the tyranny to be ostracized was Xanthippos son of Arriphron" (Athenian Constitution 22).

The procedure was used frequently in the 480's and less often thereafter. While an interesting idea, it did not really work to curb ambition in the long run, for a prominent man, if powerful enough, could use it to eliminate his chief rival. Such an occurrence is recorded in 443 B.C., when Perikles was facing vociferous criticism of his policies, especially his building program. An ostracism was held, which resulted in the exile of his main opponent, Thucydides the son of Melesias (not Thucydides the historian). Plutarch describes the final ostracism and the abandonment of the procedure in 417 B.C.:

Now the sentence of ostracism was not a chastisement of base practices, instead it was speciously called a humbling and docking of oppressive prestige and power; but it was really a merciful exorcism of the spirit of jealous hate, which thus vented its malignant desire to injure, not in some irreparable evil, but in a mere change of residence for ten years. And when ignoble men of the baser sort came to be subjected to this penalty it ceased to be inflicted at all, and Hyperbolos was the last to be thus ostracized. It is said that Hyperbolos was ostracized for the following reason. Alkibiades and Nikias had the greatest power in the state and were at odds. Accordingly, when the people were about to exercise the ostracism, and were clearly going to vote against one or the other of these two men, they came to terms with one another, united their opposing factions, and effected the ostracism of Hyperbolos. The people were incensed at this for they felt that the institution had been insulted and abused, and so they abandoned it utterly and put an end to it. (Life of Aristeides 73-4)
Ostrakon of Perikles, candidate for ostracism in the mid-5th century B.C. Max. dim.: 0.07 m. Athens, Agora Museum P 16755. Inscribed: ΠΕΡΙΚΛΕΣ ΧΣΑΝΘΙΠΠΟ, Perikles son of Xanthippos. After Kimon's ostracism, Perikles rose to power as leader of the democratic party. Elected strategos (general) year after year, he diverted the funds of the Delian League, established for the defense of Greece, to magnificent building programs in Athens, among them the rebuilding of the Acropolis. He may often have been a candidate for ostracism but was never ostracized.
Ostrakon of Thucydides, ostracized in 443 B.C. Max. dim.: 0.13 m. Athens, Agora Museum P 29461. Inscribed: ΘΟΚΥΔΙΔΗΣ, Thucydides. This Thucydides, the son of Melesias, may have been the maternal grandfather of the historian Thucydides. He was opposed to Perikles and especially to his building program. His ostracism left Perikles as the uncontested political leader of the Athenian state.

Useless immediately after the counting, the actual ostraka were simply discarded in the street or any convenient hole. Like most baked pottery, ostraka are virtually indestructible; excavations in Athens have produced over 11,000 examples. More than any literary text, the ostraka bring to life a sense of Athenian power politics as waged centuries ago. They preserve the names of all the well-known statesmen as well as several unknown aspirants to political power.

Ostrakon of Aristeides, ostracized in 482 B.C. Max. dim.: .0125 m. Athens, Agora Museum P 9973. Inscribed: ΑΡΙΣΤΕΙΔΕΣ ΛΥΣΙΜΑΤΟ, Aristeides son of Lysimachos. Plutarch tells an anecdote about the ostracism of Aristeides: ... while the votes were being written down, an illiterate and uncouth rustic handed his piece of earthenware to Aristeides and asked him to write the name Aristeides on it. The latter was astonished and asked the man what harm Aristeides had ever done him. "None whatever," was the reply, "I do not even know the fellow, but I am sick of hearing him called 'The just' everywhere! When he heard this, Aristeides said nothing, but wrote his name on the ostrakon and handed it back. (Aristeides 7, translated by Ian Scott-Kilvert)
Ostrakon of Kimon, ostracized in 461 B.C. Max. dim.: 0.106 m. Athens, Agora Museum P 18555. Inscribed: ΚΙΜΟΝ ΜΙΛΤΙΑΔΟ, Kimon son of Miltiades. Kimon, influential statesman and soldier of the 470's and 460's B.C., was the leader of an aristocratic faction, which brought him into opposition with Perikles and other democrats and eventually led to his ostracism. He was recalled before five years had elapsed.
Ostrakon of Hippokrates, candidate for ostracism in the 480's B.C. Max. dim.: 0.10 m. Athens, Agora Museum P 6036. Inscribed twice ΗΙΠΠΟΚΡΑΤΕΣ ΑΛΚΜΕΟΝΙΔΟ, Hippokrates son of Alkmeonides. This Hippokrates is not otherwise known, but he must have been a member of the Alkmeonid family and, like the father of Megakles (14.1), may have had a connection to the Peisistratid tyrants.
Excavations in the Athenian Agora are conducted by the American School of Classical Studies.
Primary funding is provided by the Packard Humanities Institute (PHI).