The word ostracism comes from the Greek ostrakio, which in turn derives from ostrakon, which means potsherd. During the annual vote on ostracism, the men of Athens would write the name of the person they'd like to see banished on a potsherd. The man named on the most sherds was sent into exile, normally for a period of ten years.

Curiously enough, this was normally not considered a punishment, nor was it something shameful. It was merely a mechanism for maintaining political stability. Those ostracised were generally men who had become too powerful or influential for the common good, and they were welcome back when ten years had passed.

In his Athenian Constitution, Aristotle notes that the first person to have been ostracised from Athens was Hipparchus.