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.
Provisions of Oxford
The 1258 Provisions had a significant effect upon the development of the English Common Law, limiting in part the expansion of royal jurisdiction by way of the number of available writs, but in the main confirming the importance of the common law of the land for all, from king to commoner.