The Diocese of Tortona () is a Latin Church ecclesiastical territory or diocese of the Catholic Church in Northern Italy, spanning parts of three regions of Piedmont (Province of Alessandria), Lombardy (Province of Pavia) and Liguria (Province of Genoa). It is a suffragan diocese in the ecclesiastical province of the metropolitan Archdiocese of Genoa and forms part of the ecclesiastical region of Liguria. The diocese claims to be one of the oldest in Lombardy and the Piedmont.
History
According to legend, which is, however, a late one, the first Bishop of Tortona was Marcian of Tortona martyred under the Emperor Hadrian. Francesco Lanzoni has pointed out that the list of bishops that leads back to Marcian of Tortona is a compilation of the 16th century and that its contents are highly suspect. Additionally, the story of Bishop Marcian depends on a hagiographical source of the 10th century, which is full of anachronisms. Fedele Savio points out that the earliest document referring to Marcian was written between 729 and 820, and that it neither calls Marcian a bishop nor the Bishop of Tortona; and, as he points out, the letter of Bishop Eusebius of Vercelli, written to the people of Tortona from his exile in Scythopolis in 356, makes no mention of a bishop. The Bishop of Tortona, Vincenzo Capelli, nonetheless organized an event in October 1875 to celebrate the 18the centenary of Martianus' episcopal consecration.
In the first half of the fourth century, Tortona was a suffragan of the diocese of Milan.
The first bishop, according to Fedele Savio, was St. Innocentius, who in his opinion was the immediate predecessor of St. Exuperantius (381), the first of whom we have certain historical record, and who was highly praised in a sermon of Maximus of Turin (or of Ambrose of Milan). Few other names of bishops of the early period are known; but from the tenth century the list is more complete.
In 877, Pope John VIII, fearful of the continued Saracen raids on the west coast of Italy, begged for assistance from the Emperor Charles the Bald. When he arrived in Italy, Charles met the Pope at Pavia, but was discomfited to discover that his own Viceroy for Italy, Boso, and the Italian nobility were unenthusiastic about proposed operations. Then, Carloman of Bavaria, seizing the opportunity to recover the kingdom in Italy of his father, Louis the German, crossed the Alps into Italy with his army. Charles and the Pope retreated to Tortona, where, Pope Gregory crowned Charles' wife Richilde as Empress. Charles then began his retreat into Provence, but died in the Mont Cenis pass on 6 October 877.
In the 1120s, Bishop Peter caused considerable trouble by illegally and uncanonically taking control of five parishes belonging to the diocese of Bobbio. The Bishop of Bobbio complained to the Pope, and therefore, on 26 November 1128, Pope Honorius II decreed that Bishop Peter should return those churches immediately; if he still had issues, he could bring them to the papal Court. In 1180 Bishop Oberto was one of four bishops who were found to be illegally occupying parishes belonging to the Monastery of S. Maria Theodota, and they were all ordered by Pope Alexander III to return the lands in question. The demands had to be repeated for a decade, by Popes Lucius III, Urban III, and Gregory VIII.
Another Bishop Pietro was one of those who in 1241 were made prisoners by Emperor Frederick II at the Battle of Giglio, while on their way to attend a council in Rome called by Pope Gregory IX. Bishop Melchiorre Busseto in 1284 was killed by the followers of William VII, Marquess of Montferrat, for which the Marquess lost all his rights of patronage in the Diocese of Tortona, and was compelled, barefoot and clad in a shirt only, to walk from the scene of the bishop's murder to the cathedral.
Bishop Melchior Busetto (1255–1284) was responsible for building the Hospitale San Michele, as well as the parish church of Sant'Andrea, which collapsed in ruins in 1622.
In the time of Michele Marliano (1461) the body of St. Rochus was found at Voghera, which was the cause of a lengthy controversy with Arles, which possessed the relics of St. Rochus of Montpellier.