Athenians voted to exile a neighbour by scratching his name on broken pottery
Once a year the Athenian assembly asked a strange question: shall we banish someone? If the answer was yes, citizens returned two months later with names scratched on pottery shards, and the man with the most votes left the city for ten years. Nobody charged him with anything, and he could offer no defence.
The word ostracism comes from ostraka, fragments of broken pottery that served as free scrap paper when imported papyrus was too costly to waste. The question was put in the sixth month of the civic year, roughly January or February. If a majority agreed, voters gathered in a fenced-off part of the agora; many could not write, so scribes inscribed names for them, and shards were stacked face down to keep ballots anonymous. Plutarch says at least 6,000 votes had to be cast for the result to count, the figure most historians accept.
The penalty was oddly gentle. The loser had ten days to go, faced death only if he came back early, kept his property and status, and returned after a decade without disgrace. The assembly could recall exiles in emergencies, as it did for Pericles' father Xanthippus and Aristides before the Persian invasion of 479 BC. Compared with trials, which could end in execution or ruinous fines, ostracism was a preventive tool that tended to lower political temperature rather than raise it.
Aristotle credits the reformer Cleisthenes with inventing it around 506 BC, but the first victim, Hipparchos, a relative of the former tyrant Peisistratos, was not expelled until 487 BC. Early targets were linked to tyranny or Persia; later votes settled policy fights, as when Thucydides son of Melesias, an opponent of Pericles' building programme, was sent away in 443 BC. The practice was used only in the fifth century, ending with Hyperbolus around 417 BC.
Archaeology adds texture. About 12,000 political ostraka have been dug up in Athens, and a single undated vote against Megacles accounts for 4,647 of them. A well near the Acropolis held 190 shards naming Themistocles, written by just fourteen hands, perhaps campaign handouts or ready-made ballots for sale. Some shards simply read hunger, a vote cast against famine itself.
Source: Ostracism