Originally, John Doe was a sham name used to indicate any plaintiff in an action of ejectment (a legal action to regain property) in civil court. Richard Roe was the counterpart, to indicate the defendant. These fake names were used in delicate legal matters, a practice that was abolished in English law in 1852. Since then, John Doe has been used to indicate any man of unknown name, with Jane Doe used for females.
Under the legal terminology of Ancient Rome, the names “Numerius Negidius” and “Aulus Agerius” were used in relation to hypothetical defendants and plaintiffs.
The name “John Doe” (or “John Do”), “Richard Roe”, along with “John Roe”, were regularly invoked in English legal instruments to satisfy technical requirements governing standing and jurisdiction, beginning perhaps as early as the reign of England’s King Edward III (1327–1377).[8] Though the rationale behind the choices of Doe and Roe is unknown, there are many suggested folk etymologies. Other fictitious names for a person involved in litigation in medieval English law were “John Noakes” (or “Nokes”) and “John-a-Stiles” (or “John Stiles”). The Oxford English Dictionary states that John Doe is “the name given to the fictitious lessee of the plaintiff, in the (now obsolete in the UK) mixed action of ejectment, the fictitious defendant being called Richard Roe”.
This usage is mocked in the 1834 English song “John Doe and Richard Roe”:
Two giants live in Britain’s land,
John Doe and Richard Roe,
Who always travel hand in hand,
John Doe and Richard Roe.
Their fee-faw-fum’s an ancient plan
To smell the purse of an Englishman,
And, ‘ecod, they’ll suck it all they can,
John Doe and Richard Roe …
This particular use became obsolete in the UK in 1852:
As is well known, the device of involving real people as notional lessees and ejectors was used to enable freeholders to sue the real ejectors. These were then replaced by the fictional characters John Doe and Richard Roe. Eventually the medieval remedies were (mostly) abolished by the Real Property Limitation Act of 1833; the fictional characters of John Doe and Richard Roe by the Common Law Procedure Act 1852; and the forms of action themselves by the Judicature Acts 1873–75.”
Secretary of State for Environment, Food, and Rural Affairs v Meier and others (2009).In the UK, usage of “John Doe” survives mainly in the form of John Doe injunction or John Doe order (see above).
8.02 If an unknown person has possession of the confidential personal information and is threatening to disclose it, a ‘John Doe’ injunction may be sought against that person. The first time this form of injunction was used since 1852 in the United Kingdom was in 2005 when lawyers acting for JK Rowling and her publishers obtained an interim order against an unidentified person who had offered to sell chapters of a stolen copy of an unpublished Harry Potter novel to the media.