BAGNOREGIO, DIOCESE of. — In Lazio, in the province of Viterbo, with an area of 300 sq. km and a population of 30,000 inhabitants distributed among 28 parishes, with 34 diocesan priests and 15 religious priests. It has its own minor seminary and a major seminary shared with the other dioceses of upper Lazio in Viterbo. B. rises between Orvieto and Viterbo, on a steep plateau, between two tributaries of the Tiber. Of Etruscan origin, in Roman times it was known by the name of Novem Pagi. Balneum regis, then as Bagnorea until 1922 and thereafter as B.; it took its name from the once-famous baths, of which nothing remains but a poor sulphurous-water spring. Almost completely destroyed by the Lombards in 606, it was rebuilt by the last of their kings, Desiderius. Donated by Charlemagne to Hadrian I, it formed part of the Papal States until their fall. It is chiefly famous as the birthplace of the Franciscan saint and Doctor Bonaventura Fidanza (1221–74), to whom the present Cathedral is dedicated.
The Passio of Saints Amsanus and Maxima (BHL, 515–16), not earlier than the 11th century, would place the origins of Christianity in B. in the time of the great persecution under Diocletian, during which Amsanus, the son of a certain Roman named Tranquillinus, is said to have been arrested in Rome together with his baptismal godmother, Maxima. While she is said to have been killed in prison, Amsanus is said to have fled to B. and then to Siena, where he was beheaded. L. Duchesne is of the opinion that the dioceses of B. and Orvieto succeeded that of Bolsena. The first certain document mentioning a bishop of B. is the letter written by St. Gregory the Great (Registr. epist., X, 3), requesting information about the deacon Giovanni, elected by the clergy and people of B. as their bishop.
Another bishop of B. appears among the signatories of the Lateran Council of 769. The list of the bishops of B. is frequently interrupted during the centuries of the Middle Ages. The diocese is immediately subject to the Holy See.