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.
Rule of law in the United Kingdom
The rule of law is one of the longest established common law fundamental principles of the governance of the United Kingdom, dating to Magna Carta of 1215, particularly jurisprudence following its late 13th century re-drafting. It as a minimum subjects an otherwise absolute monarch (executive) and all free people within its jurisdictions, primarily those of England and Wales, Scotland and Northern Ireland to legal doctrines known as the general principles of law. It has evolved to work only alongside equal application of the law to all free people 'equality before the law' and within the framework of the constitutional monarchy supports the legal doctrine of parliamentary sovereignty. Exactly what it entails beyond this and the way that different aspects of the rule of law principle are applied, depends on the specific situation and era.