Dioceses immediately subject to the Holy See


Dioceses immediately subject to the Holy See in the Catholic Church are dioceses or ecclesiastical jurisdictions directly dependent upon the Holy See and not subject to the supervisory authority of a metropolitan archbishop, an exemption under Catholic canon law. An equivalent expression, now outdated, is exempt diocese.

The Traditional Rule

The normal rule is that dioceses are assigned to various ecclesiastical provinces headed by a metropolitan archbishop, and these are known as suffragan dioceses. It may occur that, for especially historical reasons or other immediate concerns, a diocese—or, more exceptionally, an archdiocese—is not included within an ecclesiastical province but instead depends directly on the Holy See.
With the institution of ecclesiastical regions in some countries, the immediately subject dioceses also become part of these institutions, thereby reducing the difference between suffragan dioceses and those immediately subject.
A particular case is that of the ecclesiastical region of Lazio in Italy: the ecclesiastical province consists solely of the Diocese of Rome and the seven suburbicarian dioceses, and the remaining dioceses of the ecclesiastical region are subject to the Apostolic See. These dioceses are located within the 100-mile radius surrounding Rome, the former jurisdiction of the district of the Praefectus Urbis, a role that was preserved until August 15, 1972, by the Cardinal Vicar of Rome. The bishops of these dioceses must participate in the pontifical consistories and have the privilege of including four tassels on their episcopal coats of arms, just like the archbishops. In 1972 the term "of number" was abolished, and the bishops were granted the right to participate in consistories and to include the four tassels on their coats of arms.
The same applies to territorial abbeys or to the eparchies of the Eastern Catholic Churches, which are withdrawn from the ecclesiastical provinces in which they are located.
There are also historically originated cases, such as that of Lucca, which are legacies of times when there were no state boundaries separating the closest metropolises.

Vatican II

The decree of the Vatican II document Christus Dominus, promulgated in 1965, established that all dioceses must belong to an ecclesiastical province. It was established by rule that dioceses immediately subject to the Holy See must form part of the nearest province.

Exempt Dioceses

These dioceses are exempt from belonging to any ecclesiastical province, hence only the Vatican can exert the authority and coordinating functions normally falling to the Metropolitan Archbishop. They are grouped here geographically. Nevertheless, most belong to an episcopal conference, in which case the more relevant mention is in its geographical region, as exempt dioceses as such do not have specific ties with each other.