Long before the coming of the Bill of Rights in written Constitutions, the common law has had the greatest regard for the personal liberty of the individual. In order to safeguard that liberty, the remedy of habeas corpus was always available to persons deprived of their liberty unlawfully. This ancient writ has been incorporated into the modern Constitution as a fundamental right and enforceable as other rights protected by virtue of their entrenchment in those Constitutions. This article aims to bring together the various understanding of habeas corpus at common law and the principles governing the writ in common law jurisdictions. The discussion is approached through a twelve-point construct thus providing a brief conspectus of the subject matter, such that one could have a better understanding of the subject as applied in most common law jurisdictions.