CAThedral. — It is the principal church of a diocese, where the bishop’s cathedra or throne is located. Also called the “Duomo” or, by excellence, the “house of God,” it is the most important church in the diocese (ecclesia mater and maior). If the bishop holds a particular dignity or jurisdiction, the cathedral receives a corresponding title, such as metropolitan, primatial, or patriarchal.
The cathedral must be solemnly consecrated (cf. can. 1165 §3), and the anniversary of this consecration or dedication is celebrated throughout the diocese with a double rite of the first class and octave; religious communities observe it without the octave. The titular saint is likewise solemnized with the same rite. According to ancient custom, the episcopal cathedra, or throne, must be situated at the back of the apse, with the altar in front, so that the celebrant faces the people. If the altar is placed against the wall, the throne stands to the Gospel side.
The daily office in the cathedral is conducted by the Chapter (v.), consisting of the recitation of the Divine Office and the sung Mass of the day. The most solemn functions take place in the cathedral, such as general sacred ordinations, “vocatis et praesentibus canonicis,” on the Saturdays of the Ember Days, on the Saturday of “Sitientes,” and on Holy Saturday (can. 1006 and 1009); the announcement of movable feasts after the Gospel of the Epiphany Mass; the consecration of the Holy Oils; and the washing of feet on Holy Thursday. On Easter and another day of his choosing, the bishop grants the papal blessing with a plenary indulgence in the cathedral, in accordance with can. 914.
The *Codex Iuris Canonici* contains various norms regarding cathedrals, in addition to those already cited. These norms pertain to: the obligation of repairs (can. 1186: V. chiesa), the reservation of the Most Holy Eucharist (can. 1268 §3: V. eucaristia), the right of the bishop to receive sacred furnishings upon his death (can. 1299: V. sacre), and conversely, the obligation of the cathedral to provide the bishop with sacred furnishings and everything necessary for Mass and pontifical functions free of charge (can. 1303 §1: V. sacre), the judicial competence for cases concerning the temporal rights or goods of the cathedral (can. 1576 §1, which prescribes a collegial tribunal of three judges), the bishop’s capacity to act in legal proceedings on behalf of the cathedral (can. 1653 §1), and the effects of local interdict on the cathedral (cann. 2271 n. 2 and 2272: V. interdetto).
The Cathedral in Urban Planning. — Regarding location, it is noteworthy that the earliest medieval cathedrals were not built in the heart of the city but on its outskirts, and sometimes entirely outside the inhabited area (Pisa). Mengozzi suggests that this may have been due to difficulties faced by the Church in its early centuries or to a lack of available land within the urban core. Gantner, however, argues that the isolation of the sacred building from profane spaces served symbolic purposes.
More likely, defensive considerations played a decisive role, as evidenced by the connection between the cathedral and the castle (Fondi, now no longer a bishopric) or its placement near key thoroughfares, such as bridges (Verona, and possibly Cologne), or along the original city walls in Roman-founded cities (Como, Lucca, and many centers along the Via Aemilia). Additionally, this location may have served the spiritual needs of both the city and the countryside.
The configuration of the terrain also had a decisive influence. In hilltop cities, the cathedral was often placed at the highest point, frequently overlying Roman or pre-Roman temples (e.g., Alatri, Fermo), sometimes resulting in peripheral locations (Gubbio, Spoleto, Cortona) or even sites outside the urban core (Ancona). The result was a clear separation from the rest of the built environment, giving the cathedral a prominent position over the entire settlement. Particularly striking effects are seen in river cities, where the cathedral dominates adjacent areas from natural terraces (Avignon, Basel). In flat cities, when the cathedral occupies a central position, it generally becomes the focal element and, beginning in the 13th century, the dominant feature of the main square, which often also served as a market (Cremona, Reggio Emilia, many Belgian and German cities). The square may take various planimetric forms: the L-shaped arrangement, which allows the church to present two free sides, is common in Italy (Pistoia, Foligno) and not rare in Central and Western Europe (Strasbourg, Rouen). Triangular squares, of more ancient origin (Massa Marittima), persist in some regions until the late 14th century (Antwerp). Occasionally, the square is arranged in depth, often skillfully connected to nearby squares to form an organic grouping of spaces (Todi, Ascoli Piceno).
Renaissance conceptions, after some transitional manifestations (such as Urbino, which shows a revival, with altered sensibility, of the connection between church and castle), are fully realized at Pienza, where the cathedral assumes the role of a central element in a harmoniously balanced architectural composition, integrated logically into the urban plan. The following century also demonstrates the importance of academic Mannerism in the square of Livorno, where the cathedral is framed by porticoed buildings arranged in a rigidly unified manner. The Baroque period, finally, offers in Salzburg an expression of the new spatial sensibility, with a sequence of squares surrounding the cathedral, arranged to ensure that the square can be accessed from all sides while maintaining a closed and intimate space in front.
The 18th and 19th centuries show little interest in this aspect. In the latter century, misguided criteria of isolation and a poorly understood emphasis on grandeur led to the complete alteration of the original environment, transforming ancient narrow streets into overly large and sometimes congested squares (Milan, Paris). The solutions adopted in the first decades of the 20th century for the reconstruction of earthquake-devastated Italian cities are almost always banal.
Outside Europe, some good examples of urban planning around cathedrals can be found in North Africa (Benghazi, Tripoli, Rabat). However, it is above all in Latin America that the most imposing expressions are seen over the last three centuries, particularly in Mexico City and Santiago de Chile, where the principal church of the city is scenographically surrounded by the most representative public buildings.