What is Habeas Corpus?
Habeas Corpus, in law, a court order or writ, designed to determine whether a person is being legally detained. The term is Latin and means "(that) you have the body." A writ of habeas corpus orders those who are detaining a person to bring him physically before a judge at a specific time and place so that the court may review the legal causes of his detention. The writ may be issued in criminal or civil cases on behalf of a person who has been detained by the police, military authorities, or private persons.
In English law the privilege of habeas corpus can be traced at least as far back as the Magna Carta of 1215. Until about 1500 it was used only in cases of restraint imposed by private persons. The struggle of Parliament to limit the power of the English kings led to the enactment of several habeas corpus acts (the most important being the Habeas Corpus Act of 1679), which extended the power of the writ to cover arrests by the king. Today it requires an Act of Parliament to suspend issuance of such writs in Britain.
Article 1, Section 9 of the U.S. Constitution requires that "The Privilege of the Writ of Habeas Corpus shall not be suspended, unless when in Cases of Rebellion or Invasion the public safety may require it." It was on the ground of rebellion that President Lincoln suspended the writ at the beginning of the Civil War. His doing so aroused some degree of judicial doubt and debate at the time, led by Chief Justice of the Supreme Court Roger Taney. However, the U.S. Congress later delegated to Lincoln the power to suspend the writ for the duration of the war emergency.
Habeas corpus is widely used in federal courts to test the constitutionality of state criminal convictions.