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. Prior to the Norman Conquest, much of England's legal business took place in the local folk courts of its various shires and hundreds. A variety of other individual courts also existed across the land: urban boroughs and merchant fairs held their own courts, as did the universities of Oxford and Cambridge, and large landholders also held their own manorial and seigniorial courts as needed. Additionally, the Catholic Church operated its own court system that adjudicated issues of canon law.
Oliver Wendell Holmes Jr.
In 1881, in "The Common Law", Holmes brought together into a coherent whole his earlier articles and lectures concerning the history of the common law, judicial decisions in England and the United States, which he interpreted from the perspective of a practicing lawyer. What counted as law, to a lawyer, was what judges did in particular cases. Law was what the state would enforce, through violence if necessary; echoes of his experience in the Civil War were always present in his writings. Judges decided where and when the force of the state would be brought to bear, and judges in the modern world tended to consult facts and consequences when deciding what conduct to punish. The decisions of judges, viewed over time, determined the rules of conduct, the legal duties, by which all were bound. Judges did not and should not consult any external system of morality, certainly not a system imposed by the Deity.