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.
Middle Ages
Legal studies advanced during the 12th century. Both secular law and canon law, or ecclesiastical law, were studied in the High Middle Ages. Secular law, or Roman law, was advanced greatly by the discovery of the "Corpus Juris Civilis" in the 11th century, and by 1100 Roman law was being taught at Bologna. This led to the recording and standardisation of legal codes throughout Western Europe. Canon law was also studied, and around 1140 a monk named Gratian (fl. 12th century), a teacher at Bologna, wrote what became the standard text of canon law—the "Decretum".