<P> The main sources for the history of the common law in the Middle Ages are the plea rolls and the Year Books . The plea rolls, which were the official court records for the Courts of Common Pleas and King's Bench, were written in Latin . The rolls were made up in bundles by law term: Hilary, Easter, Trinity, and Michaelmas, or winter, spring, summer, and autumn . They are currently deposited in the UK National Archives, by whose permission images of the rolls for the Courts of Common Pleas, King's Bench, and Exchequer of Pleas, from the 13th century to the 17th, can be viewed online at the Anglo - American Legal Tradition site (The O'Quinn Law Library of the University of Houston Law Center). </P> <P> The term "common law" originally derives from the 1150s and 1160s, when Henry II of England established the secular English tribunals . The "common law" was the law that emerged as "common" throughout the realm (as distinct from the various legal codes that preceded it, such as Mercian law, the Danelaw and the law of Wessex) as the king's judges followed each other's decisions to create a unified common law throughout England . From at least the 11th century and continuing for several centuries after that, there were several different circuits in the royal court system, served by itinerant judges who would travel from town to town dispensing the King's justice . The term "common law" was used to describe the law held in common between the circuits and the different stops in each circuit . The more widely a particular law was recognized, the more weight it held, whereas purely local customs were generally subordinate to law recognized in a plurality of jurisdictions . </P> <P> The doctrine of precedent developed during the 12th and 13th centuries, as the collective judicial decisions that were based in tradition, custom and precedent . </P> <P> The form of reasoning used in common law is known as casuistry or case - based reasoning . The common law, as applied in civil cases (as distinct from criminal cases), was devised as a means of compensating someone for wrongful acts known as torts, including both intentional torts and torts caused by negligence, and as developing the body of law recognizing and regulating contracts . The type of procedure practiced in common law courts is known as the adversarial system; this is also a development of the common law . </P>

When did the doctrine of precedent begin to emerge in english common law