A territorial abbey (or territorial abbacy) is a particular church of the Catholic Church comprising defined territory which is not part of a diocese but surrounds an abbey or monastery whose abbot or superior functions as ordinary for all Catholics and parishes in the territory. Such an abbot is called a territorial abbot or nullius diœceseos (abbreviated nullius and Latin for "abbot of no diocese"). A territorial abbot thus differs from an ordinary abbot, who exercises authority only within the monastery's walls or to monks or canons who have taken their vows there. A territorial abbot is equivalent to a diocesan bishop in Catholic canon law.
The practice arose in part because abbeys served the spiritual needs of Catholics who lived near the monastery, especially in mission territories. The monastery's own chapel was a space of public worship for the laity who had settled nearby, and the monks could also serve as parish clergy in churches near the monastery. The abbot of the monastery, although having received only the priesthood in the sacrament of Holy Orders, was invested with the same administrative authority under canon law as a diocesan bishop for a given territory around the abbey. Thus, with the exception of conferring ordination on priests, the territorial abbot could do almost everything a diocesan bishop would for those under his care, including incardinate (that is, enroll under his jurisdiction) even non-monastic priests and deacons for service in parishes. The territorial abbot, like other abbots and archabbots, had the right to use an episcopal coat of arms and to wear the mitre, the crosier, the ring, and the pectoral cross; if the abbot had been ordained to the episcopacy (very rare), he had the power to ordain his religious who were candidates to the transitional and permanent diaconate and to the priesthood, though they usually had to attend a seminary house of formation located outside the abbot's territory.
Though territorial (like other) abbots are elected by the monks of their abbey, a territorial abbot can only receive the abbatial blessing and be installed under mandate from the pope, just as a bishop cannot be ordained and installed as ordinary of a diocese without such a mandate.
After the Second Vatican Council, more emphasis has been placed on the unique nature of the episcopacy and on the traditional organization of the church into dioceses under bishops. As such, abbeys nullius have been phased out in favor of the erection of new dioceses or the absorption of the territory into an existing diocese. A few ancient abbeys nullius still exist in Europe, and one in Korea.
Present territorial abbeys
There are eleven remaining territorial abbeys, as listed by the Vatican in the Annuario Pontificio:
- Monte Cassino (lost most territory to the Diocese of Sora-Aquino-Pontecorvo)
- Monte Oliveto Maggiore
- Santissima Trinità di Cava de' Tirreni
- Santa Maria (Saint Mary) of Grottaferrata (abbey of the Italo-Albanian Catholic Church, and the only territorial abbey not of the Latin Church)
- Tŏkwon (덕원), North Korea Ecclesiastically united with South Korea, Tŏkwon (the only territorial abbey outside Europe) has been vacant for many years. The Abbot of Waegwan is the present apostolic administrator of the Tŏkwon abbacy. It has not been united with any diocese throughout Korea due to the effective vacancy of the ones in North Korea and the lack of effective jurisdiction applied by the Church in South Korea.
Titular territorial abbeys
The following abbeys were previously territorial abbeys that were subsequently united with neighbouring dioceses:
- Abbey of the Santissima Trinità of Venosa (united with the Diocese of Melfi-Rapolla-Venosa)
- Farfa (united with the Diocese of Sabina–Poggio Mirteto)
- Fontevivo (united with the Diocese of Parma)
- Pomposa (united with the Archdiocese of Ferrara–Comacchio)
- San Columbano (united with the Piacenza–Bobbio)
- San Martino al Monte Cimino (united with the Diocese of Viterbo)
- San Michele Arcangelo di Montescaglioso (united with the Archdiocese of Matera–Irsina)
- San Salvatore Maggiore (united with the Diocese of Rieti)
- Santa Maria di Polsi (united with the Diocese of Locri–Gerace)
- Santissimo Salvatore (united with the Archdiocese of Messina-Lipari-Santa Lucia del Mela)
Other historical territorial abbacies
Historically there have been more, such as :
- in Italy : Pinerolo, a prince-abbacy in Piedmont later transformed into a bishopric Abbey of Saint Paul Outside the Walls in Rome (jurisdiction passed to a newly named archpriest in 2005)
- in Albania : St. Alexander Orosci (Albanian: Shën Llezhri i Oroshi), enclaved in the Albanian Diocese of Alessio (now Lezhë), promoted in 1888 to the present Roman Catholic Diocese of Rrëshen
- in Brazil : Territorial Abbey of Our Lady of Mountserrat in Rio de Janeiro Territorial Abbey of Claraval (named after Cistercian mother abbey Clairvaux)
- in North America : Belmont Abbey – Mary, Help of Christians, which was the territorial abbey of half of North Carolina from 1910 until 1960, when it lost its last extra-abbatial territory. It was formally suppressed as a territorial abbey in 1977. St. Peter-Muenster, which from 1921 until 1998 served a remote area of Saskatchewan, Canada. The abbey still exists, but its territorial jurisdiction and duties were absorbed by the Diocese of Saskatoon.
- in South Africa : Territorial Abbey of Pietersburg, promoted to bishopric of Pietersburg and renamed Diocese of Polokwane; the Benedictine abbey persists separately
- in Tanzania : Territorial Abbacy of Lindi, renamed Territorial Abbacy of Peramiho, promoted as Diocese of Songea, now Metropolitan Territorial Abbacy of Ndanda, promoted as Diocese of Mtwara)