An ecclesiastical court, also called court Christian or court spiritual, is any of certain courts having jurisdiction mainly in spiritual or religious matters. In the Middle Ages in many areas of Europe these courts had much wider powers than before the development of nation states. They were experts in interpreting Canon law, a basis of which was the Corpus Juris Civilis of Justinian which is considered the source of the civil law legal tradition.
The tribunals of the Catholic Church are governed by the Code of Canon Law in the case of the Western Church (Latin or Roman Rite), and the Code of Canons of the Eastern Churches in the case of the Eastern Catholic Churches (Byzantine, Ukrainian, Maronite, Melkite, etc.). Both systems of canon law underwent massive revisions in the late 20th century, resulting in the new code for the Latin Rite in 1983, and the compilation for the first time of the Eastern Rite Code in 1990.
Cases normally originate in the tribunal of the particular church (i.e. the diocese or eparchy) of the parties to the case. This tribunal in canon law is called the tribunal of first instance. The bishop of the church possesses the power to judge for his church; however, since the bishop has many different duties in his diocese, most cases are handled by judges whom he appoints, led by a priest known as the judicial vicar or officialis.
A single judge can handle normal contentious and penal cases. A college of at least three judges, however, must try cases involving an excommunication, the dismissal of a cleric, or the annulment of the bond of marriage or of sacred ordination (can. 1425 §1). The bishop can assign up to five judges to a case that is very difficult or important (can. 1425 §2). Otherwise, the judicial vicar assigns cases to the judges and, in those cases which require three or more judges, presides over the panel or assigns one of his assistant judicial vicars to preside, if there are any. The judicial vicar and the assistant judicial vicars must be priests with doctorates or at least licenses in canon law. The other judges need only be clerics with licenses, but the episcopal conference can permit members of the laity with the same academic qualifications to serve as judges on a panel.