Civil, common law and canon law were different legal systems co-existing uncomfortably; some way had to be found to permit coexistence. From the 12c, the *clergy had a privilege of belonging to the jurisdiction of the ecclesiastical courts. By the 13c, these courts had come to exercise jurisdiction over a great range of matters we might consider the province of civil law. For instance, the ecclesiastical courts had jurisdiction over marriage and legitimacy, and in the matter of wills and church land outside the feudal system. They also had the power to interpret bequests of personal estates and to settle disputes over wills, and to impose punishment of mortal sins and breaches of faith. Grants of probate and even the behaviour and actions of executors were under these courts' purview. Furthermore these Church courts dealt with any member of the Church, from the lowliest deacon or clerk, who committed an offence. Conflict between crown and Church over these courts arose from the fact that offenders in Church courts were deemed not properly punished: a murderer in a royal court would be mutilated or heavily fined, in a Church court a cleric would be defrocked - that being the severest penalty an ecclesiastical court could impose. -
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.