Prolonged absence from one's country of origin, either enforced by government authorities or by voluntary action in the fear of persecution for reasons of race, religion, nationality or political opinion, constitutes exile. Transportation of prisoners, political or otherwise, to isolated areas is another forms of banishment. Individuals forced into exile are made outcasts and are deprived of the comfort and protection of their group. Often they have to live in a different climate, learn a new language, new social customs and start their professional and family life anew. They may be resentful of, or resented by, society in their host country. Where exiles live freely in another country they may cause international conflict and may put out propaganda against the oppressive regime in their country of origin. Exile for political reasons often deprives a minority or opposition group of its leaders and spokesmen. If the exiles are allowed to return to the country after an extended period of time, they may face serious political, economic and social disadvantages.
Exile and banishment probably originated in tribal custom as a means of punishment. Transportation was a common practice in Europe from the 15th century to the 19th century; in the 20th century political reasons has become the major cause of exile.