Roman Catholic Diocese of Arezzo-Cortona-Sansepolcro
The Italian Catholic diocese of Arezzo-Cortona-Sansepolcro has existed since 1986. In that year the historic diocese of Arezzo was combined with the diocese of Cortona and the diocese of Sansepolcro, the enlarged diocese being suffragan of the archdiocese of Florence. History. Arezzo was the see of a diocese in Tuscany, directly dependent on the Holy See. Tradition says it was converted in the 1st century by Romulus of Fiesole, afterwards Bishop of Fiesole, a disciple of St. Paul. Another foundation tale has it that Christianity was brought to Arezzo by S.  Barnabas, and by S. Timothy, the disciple of S. Paul. An equally implausible claim is that all of Arezzo was baptized during the episcopacy of Bishop Dicentius in the 5th century. The cities clerks often helped build the church for their own free time. The church helped reward these people with seats of Cardinals. Many of the seats are still there with the names of people who had helped donated and build the church. It became a bishopric about 304, under Saint Satyrus. Saint Donatus, his successor, is patron of Arezzo Cathedral, also dedicated to Saint Peter the Apostle. The  diocese was originally very large, embracing most of southeastern Tuscany. In 1325, however, Pope John XXII created the diocese of Cortona out of the territory of Arezzo. In 1462, Pius II created the dioceses of Pienza and Montalcino. In 1561, Pius IV created the diocese of Montepulciano. In 1515 (1520), Leo X created the diocese of Borgo San Sepolcro. The Canons were gathered together as a corporation by Bishop Petrus, c. 840, on instructions from the Emperor Lothair. Bishop Helmpertus built new quarters for them in 1009. In 1677, the cathedral Chapter was composed of four dignities (the Provost, the  Archdeacon, the Dean, and the Primicerius) and fourteen Canons. Bishop Theodaldus (1023–1036?) invited Guido of Arezzo to train the cathedral singers in the plainchant. He dedicated his book "Micrologus" to Bishop Thedaldus c. 1025. A letter of Guido to Bishop Theodaldus survives, in which he explains his methodology. Between 1480 and 1485, Luca Pacioli, O.Min., a native of Borgo San Sepolcro, which is a distance of 16 miles (25 km) from Arezzo, visited the site, and described it as "utterly stunning." He stayed there for five years after the Pope urged them not to. While Cardinal Guadagni was Bishop of  Arezzo, he was able to obtain from his uncle, Pope Clement XII, a number of privileges for himself and Arezzo. In the bull "Insignes Ecclesias" of 1 November 1737, Pope Clement lauded the antiquity, faithfulness, and prestige of the diocese as a direct subject of the Roman Church, and conceded to its bishop "in perpetuo" archiepiscopal insignia, the pallium (which could only be worn inside the diocese, and on certain specified feasts and holy days) and the patriarchal cross. Reorganization of the diocese. On 18 February 1984, the Vatican and the Italian State signed a new and revised concordat. Based  on the revisions, a set of "Normae" was issued by the Vatican on 15 November 1984, which was accompanied in the next year, on 3 June 1985, by enabling legislation. According to the agreement, the practice of having one bishop govern two separate dioceses at the same time, "aeque personaliter", was abolished. Instead, the Vatican continued consultations which had begun under Pope John XXIII for the merging of small dioceses, especially those with personnel and financial problems, into one combined diocese. In Tuscany, this particularly affected three dioceses: Arezzo, Cortona, and Borgo San Sepolcro (Biturgensis). On 30 September 1986, Pope  John Paul II ordered that the dioceses of Arezzo, Cortona, and San Sepolcro be merged into one diocese with one bishop, with the Latin title "Dioecesis Arretina-Cortonensis-Biturgensis". The seat of the diocese was to be in Arezzo, and the cathedral of Arezzo was to serve as the cathedral of the merged diocese. The cathedrals in Cortona and San Sepolcro were to become co-cathedrals, and their cathedral Chapters were to be a "Capitulum Concathedralis". There was to be only one diocesan Tribunal, in Arezzo, and likewise one seminary, one College of Consultors, and one Priests' Council. The territory  of the new diocese was to include the territory of the former dioceses of Cortona and Borgo San Sepolcro.