Common law
The common lawso named because it was "common" to all the king's courts across Englandoriginated in the practices of the courts of the English kings in the centuries following the Norman Conquest in 1066. The British Empire spread the English legal system to its historical colonies, many of which retain the common law system today. These "common law systems" are legal systems that give great precedential weight to common law, and to the style of reasoning inherited from the English legal system.
Writ of prohibition
The rise in the use of writs of prohibition accompanied the consolidation of power in the English monarchy and the growth of the court system in the twelfth and thirteenth centuries. The Angevin kings, who split their time between England and France, needed strong and competent advisors to help run the government in England when they were gone. The growth of the royal bureaucracy accompanied the codification of much of the existing common law with the First Statute of Westminster (1275), which was passed during Edward I's reign. The common law courts and legal interpretation by common law judges began to become more formalized as judges moved from the role of primary lawmakers to the interpreters of statutes. While the earlier courts had had more flexibility to provide both legal and equitable relief, over the period from the late thirteenth century to the end of the fourteenth century, the consideration of equity gradually disappeared in common law courts, which was one of the reasons the Chancery, which existed before to keep the King’s Great Seal and stamp it on public documents, emerged as a separate judicial court. As the common law courts became more formalized and rigid in their procedure and jurisprudence, they also ceased using the writ of prohibition as a remedy against individual defendants.