Habeas Corpus: No Prison Without a Reason

Habeas corpus, Latin for 'you shall have the body', is a court order requiring jailers to bring a prisoner before a judge and explain the legal grounds for detention. If the grounds are unlawful, the prisoner must be released. The writ developed in medieval English courts, but kings sometimes evaded it, for example by holding people on royal command without charge. Parliament responded with the Habeas Corpus Act of 1679, which set deadlines and penalties to make the writ work.

The protection crossed the Atlantic: the US Constitution forbids suspending habeas corpus except in cases of rebellion or invasion when public safety requires it. Governments have sometimes suspended it during wars and emergencies, as Abraham Lincoln did during the Civil War, which sparked debate about security versus liberty. The idea behind it, that no one may be detained without lawful reason, is now found in the UDHR's ban on arbitrary arrest.