English law
Common law is a term with historical origins in the legal system of England. It denotes, in the first place, the judge-made law that developed from the early Middle Ages as described in a work published at the end of the 19th century, "The History of English Law before the Time of Edward I", in which Pollock and Maitland expanded the work of Coke (17th century) and Blackstone (18th century). Specifically, the law developed in England's Court of Common Pleas and other common law courts, which became also the law of the colonies settled initially under the crown of England or, later, of the United Kingdom, in North America and elsewhere; and this law as further developed after those courts in England were reorganised by the Supreme Court of Judicature Acts passed in the 1870s, and developed independently, in the legal systems of the United States and other jurisdictions, after their independence from the United Kingdom, before and after the 1870s. The term is used, in the second place, to denote the law developed by those courts, in the same periods (pre-colonial, colonial and post-colonial), as distinct from within the jurisdiction, or former jurisdiction, of other courts in England: the Court of Chancery, the ecclesiastical courts, and the Admiralty court.
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.