John Doe

Nowadays used mainly in America for a male person usually deceased who has not or cannot be identified. John of course is a generic name for bloke, chap or fellow, see also John/Johnny. John Doe was originally the name used in Britain during the 18th century for court actions where a fictitious name was required. This usage was abolished in 1852 but by then the name had acquired its generic meaning and was exported to America in the early part of the 19th century.