, depicted on the
consular diptych of
Anicius Petronius Probus (406,
Museo del tesoro della cattedrale di Aosta, ) The diocese of Aosta was founded no earlier than the 5th century. At that time it was a suffragan of the diocese of Milan. On 13 June 867,
Pope Nicholas I made it was a suffragan of the Archbishop of Vienne, and it is known that in the 11th century it was a suffragan of the
diocese of Tarentaise, a province created between 794 and 811. It then became subject to Milan again, but was restored to Tarentaise. The diocese of Aosta was suppressed by order of the Emperor Napoleon I, in 1802, an order which was given canonical effect by Pius VII in 1803. Although
Ursus is sometimes said to have been the first bishop, this is controverted. The first known bishop is
St. Eustasius, whose name coupled with Aosta is signed to a letter sent to
Pope Leo I by the second
Synod of Milan in 451. In the
cathedral treasury is a
consular diptych of
Anicius Petronius Probus, Roman consul in 406, which shows the Emperor
Honorius. (It was discovered in 1833.) From the ninth century the list of bishops is fairly complete.
Bernard of Menthon (1008), Archdeacon of Aosta, founded the hospice on the
Alps named after him, as a relief to pilgrims. In the 10th and early 11th centuries, the bishops of Aosta ruled the surrounding country as its
secular counts. The two titles were separated at or following the death of Bishop Anselm of Aosta, in 1026, owing to
Conrad II's desire to strengthen his position near the important
Little St Bernard Pass and distrust of
Burchard, Anselm's successor and a relative of various nobles opposed to Conrad's claims in Burgundy. (Burchard subsequently rose in a revolt, which failed; he was later translated to
Lyons.) His namesake,
Anselm,
Archbishop of Canterbury (1033–1109), was also a native of
Aosta and probably related to its dynasty of bishops; however, rather than remain in local service, he travelled to
Bec Abbey in
Normandy and ultimately became
primate over
Norman England instead. In 1133, Bishop Herbert, with the consent of the Provost and Canons of the Collegiate Church of S. Ursi (Ours), converted the Chapter of secular canons into an association of Canons Regular of S. Augustine. This change had the support and authority of
Pope Innocent II behind it. The first Prior of the Canons of Saint-Ours was Arnulphus, who later became Bishop of Aosta. Two of his Canons, Aimon de Quart and Walbert, later became bishops of Aosta as well. In 1134 Bishop Herbert granted the Canons the free administration of their goods, releasing them from episcopal control. In 1135 Innocent II conceded the Canons of S. Ours the right of burial and the right to elect their own Prior. This was confirmed by
Pope Lucius II in 1144, and
Pope Eugene III in 1146. In the
16th century, the honorific
Duchy of Aosta was created by
Savoy on the diocesan territory. In the Spring of 1536,
John Calvin, the famous Protestant reformer, visited Aosta as he was returning to France from Ferrara. His preaching, however, brought him to the attention of Bishop Pierre Gazin, and he was forced to flee. Following the
Concordat of 1801 between Bonaparte and
Pope Pius VII, the Pope issued a bull,
Gravissimis causis (1 June 1803), in which the number of dioceses in Piedmont was reduced to eight: Turin, Vercelli, Ivrea, Acqui, Asti, Mondovi, Alessandria and Saluzzo. Ivrea was united with the former diocese of Aosta. Bishop Paolo Giuseppe Solaro di Villanova () resigned, so as not to impede the operation of the Bull. The diocese of Aosta was re-established in 1817 by Pope Pius VII in his bull,
Beati Petri (17 July 1817).
Synods A diocesan synod was an irregularly held, but important, meeting of the bishop of a diocese and his clergy. Its purpose was (1) to proclaim generally the various decrees already issued by the bishop; (2) to discuss and ratify measures on which the bishop chose to consult with his clergy; (3) to publish statutes and decrees of the diocesan synod, of the provincial synod, and of the Holy See. Bishop Simon de Duin issued a set of Statutes for the diocese in 1280. They are concerned mostly with the administration of the sacraments and the proper conduct of clerics. A diocesan synod was held by Bishop Emeric in 1307; the Statutes issued at that time have survived. In the diocese the sacrament of Baptism was practiced by immersion rather than by sprinkling of water. Bishop Oger Moriset (1411–1433) held a synod on 9 May 1424. Bishop François de Prez (1464–1511) held a synod on 15 April 1504. Bishop André Jourdain (1832–1859) presided over a diocesan synod held on 27–29 August 1835. Bishop Joseph-Auguste Duc (1872–1907) held his first synod on 21 August 1874, his second in 1875, his third in 1876, and his sixth in September 1880.
Cathedral and Chapter The cathedral of the Assumption in Aosta was served by a Chapter of regular clergy, presumably following the Rule of Saint Benedict until (perhaps) the second half of the 9th century, when the monastic discipline seems to have been relaxed; in 1133, under Bishop Humbertus, the rule of the Canons Regular was adopted. The Chapter consisted of two dignities, the Provost and the Archdeacon, and twenty Canons. One of the Canons served as Theologus. There were also fifty-two Perpetual Chaplains and six choir boys (called the
Innocentes). A twenty-first Canon was added on 14 September 1721, through the generosity of Father Jean-Baptiste du Chatelard, Prior Commendatory of the cathedral. By 1743 there were twenty-three Canons. In the filling of vacancies in the Chapter, an unusual system was followed. In the first month of each season of the year, the Pope had the right of appointment; in the second month of each season, the Bishop enjoyed the right; in the third month, the Chapter. This system lasted down until the administration of Bishop Filiberto Alberto Bailly (1659–1691), who traded his right to nominate in February, May, August, and November to the Pope, in exchange for the right to appoint to the
cures in his diocese. ==Bishops of Aosta==