prolonged absence from one's country imposed by vested authority as a punitive measure. It most likely originated among early civilizations from the practice of designating an offender an outcast and depriving him of the comfort and protection of his group. Exile was practiced by the Greeks chiefly in cases of homicide, although ostracism was a form of exile imposed for political reasons. In Rome (Roman law), exile (exsilium) arose as a means of circumventing the death penalty (see capital punishment). Before a death sentence was pronounced, a Roman citizen could escape by voluntary exile. Later, degrees of exile were introduced, including temporary or permanent exile, exile with or without loss of citizenship, and exile with or without confiscation of property. The Romans generally determined punishment by class, applying sentences of banishment to the upper classes and sentences of forced labour to the lower classes.

From the Anglo-Saxon penalty of outlawry, English law developed the practice of banishing criminals as an alternative to capital punishment. By the 18th century, English convicts were being deported to penal colonies (penal colony) in North America and Australia. The first convoy to take the 15,800-mile (25,427 km) trip to Australia departed on May 13, 1787, with 730 prisoners. Banishment and transportation to Australia ended in 1868. In the 20th century, exile was frequently imposed for political offenses, a notorious destination being the Russian region of Siberia, especially during the era of the Soviet Union.