a law adopted by the English Parliament in 1679. One of the basic constitutional acts of Great Britain, the Habeas Corpus Act established rules governing detention and the presentation of an accused person in court, and it gave the court the right to review the legality of specific cases of arrest and detention.

According to the act, if a detained person presents a statement in which he gives sworn testimony substantiating the injustice of his detention, the judge must issue within a certain amount of time a writ requiring that the person be brought before the court for the consideration of his statement. The statement is examined by the judge in the presence of the prisoner; the judge has the right to free the prisoner—either unconditionally or on bail—or, if just cause of arrest is established, to return him to detention. The provisions of the Habaes Corpus Act do not extend to persons accused of treason. The act may be suspended by Parliament under extreme circumstances, such as war, strikes, or internal unrest.

The Habeas Corpus Act gave legislative force to the practice of habeas corpus that was followed in England as early as the 12th century. In accordance with the practice, a person could request of a court or judge an explanation of the basis for his deprivation of liberty. The term “habeas corpus” derives from the Latin phrase habeas corpus ad subjiciendum—the opening words of the writ for the presentation of the person in court.

In the USA, the practice of habeas corpus was followed as early as the colonial period. It was provided for in the Constitution of 1787 and the constitutions of the individual states after independence was won. According to the constitution, Congress has the power to suspend the guaranty of habeas corpus; however, the president may also claim the power if national security is threatened—that is, in practically any case.