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.
Law
However, the system became overly systematized—overly rigid and inflexible. As a result, as time went on, increasing numbers of citizens petitioned the King to override the common law, and on the King's behalf the Lord Chancellor gave judgment to do what was equitable in a case. From the time of Sir Thomas More, the first lawyer to be appointed as Lord Chancellor, a systematic body of equity grew up alongside the rigid common law, and developed its own Court of Chancery. At first, equity was often criticized as erratic, that it varied according to the length of the Chancellor's foot. Over time, courts of equity developed solid principles, especially under Lord Eldon. In the 19th century in England, and in 1937 in the U.S., the two systems were merged.