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, these courts had much wider powers in many areas of Europe than before the development of nation states. They were experts in interpreting canon law, a basis of which was the of Justinian, which is considered the source of the civil law legal tradition.
Catholic Church
The tribunals of the Catholic Church are governed by the 1983 Code of Canon Law in the case of the Western Church (Latin Church), 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 general revisions in the late 20th century, resulting in the new code for the Latin Church in 1983, and the compilation for the first time of the Eastern Code in 1990.
First instance
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 licentiates in canon law. The other judges need only be clerics with licentiates, but the episcopal conference can permit members of the laity with the same academic qualifications to serve as judges on a panel.
There are other officers of the tribunal. The promoter of justice, for instance, is a canon lawyer whose job is to represent the diocese as the prosecutor in penal cases and who also can intervene in contentious cases if they concern the "public good", acting as a watch dog for the people of the diocese. Another important officer is the defender of the bond, another canon lawyer whose job is to present reasons to the tribunal why a marriage is valid in cases of alleged nullity and why an ordination is valid in the rare cases of alleged nullity of Holy Orders. The tribunal also has notaries who swear in witnesses and commit their testimony to writing. Parties in a case have the right to appoint an advocate who can argue for them at the tribunal. If a person cannot afford an advocate, the tribunal can assign one to them free of charge.
Unlike courts of common law tradition, ecclesiastical tribunals do not follow the adversarial system. Based on the same Roman civil law that is behind much European law, the procedure of a canonical court is more akin to the inquisitorial system, with the judges leading the investigation. As a general rule, the defendant has the favorable presumption of law, which means that the defendant will win by default unless a majority of the judges is convinced with moral certainty of the petitioner's case (can. 1608). This presumption also applies in penal cases (can. 1728). There are few exceptions to this rule; in those cases, the burden shifts to the defendant.
Some matters cannot be introduced at the diocesan level and can only be introduced before the following: Appellate tribunal for the diocese: cases against the diocese itself or an institution represented by the diocesan bishop Roman Rota: cases against the heads of religious orders, cases against dioceses or church institutions that are immediately subject to the Holy See, and non-penal cases against bishops The Pope himself: any case where a cardinal, Eastern rite patriarch, papal legate, or head of state is a defendant and any penal case involving a bishop.