In law, common law, also known as judicial precedent, judge-made law, or case law, is the body of law created by judges and tribunals. Unlike statutory law, the common law is contained and developed within written opinions and judgments.

also common-law

n. the traditional unwritten law of England, based on custom and usage, which began to develop over a thousand years before the founding of the United States. The best of the pre-Saxon compendiums of the common law was reportedly written by a woman, Queen Martia, wife of a king of a small English kingdom. Together with a book on the "law of the monarchy" by a Duke of Cornwall, Queen Martia's work was translated into the emerging English language by King Alfred (849-899 A.D.). When William the Conqueror invaded England in 1066, he combined the best of this Anglo-Saxon law with Norman law, which resulted in the English common law, much of which was by custom and precedent rather than by written code. By the 14th century legal decisions and commentaries on the common law began providing precedents for the courts and lawyers to follow. It did not include the so-called law of equity (chancery), which came from the royal power to order or prohibit specific acts. The common law became the basic law of most states due to the Commentaries on the Laws of England, completed by Sir William Blackstone in 1769, which became every American lawyer's bible. Today almost all common law has been enacted into statutes with modern variations by all the states except Louisiana, which is still influenced by the Napoleonic Code. In some states the principles of Common Law are so basic they are applied without reference to statute.