Cardinal Hildebrandus Crassus was named Rector et Procurator Ecclesiae Mutinensis, and he subscribed documents with that title from 1150 up until 1155.

In 1231 Pope Gregory IX had to order the monastery of S. Peter in Modena to submit to the rule of the bishop of Modena, rejecting their argument that Pope Eugene's release from subjection to the bishop had had a permanent effect, and that the monastery was still in 1231 immediately subject to the Holy See (Papacy).

[10] At the end of 1540, he wrote to Cardinal Farnese, expressing his anxiety about the diocese of Modena, which he considered to be worse than Prague in terms of dubious religious discussions.

In 1796, Modena and Nonantola became part of the empire of the French Republic, expanding under the military leadership of General Napoleon Bonaparte.

[13] On 11 December 1821, Pope Pius VII confirmed in the bull Sacrorum canonum the rearrangements of the dioceses in the Duchy of Modena which had been worked out by the Sacred Consistorial Congregation.

Modena, which had been made a suffragan of Milan, was returned to the ecclesiastical province of Bologna, and its acquisition of the territorial Abbey of Nantola was confirmed.

The high altar, dedicated to S. Geminianus, was consecrated by Pope Paschal II, in the presence of Countess Matilda of Tuscany, on 8 October 1106.

[15] In 1184, Pope Lucius III visited Modena, accompanied by ten cardinals, the Archbishops of Ravenna and Lyons, and the Bishops of Reggio and Bologna.

A document of the Emperor Guido (891–894), dated November 892, speaks of granting Bishop Leudoinus powers for building ramparts ad muniendam ipsam sanctam Ecclesiam suamque constitutam Canonicam.

[23] During the episcopate of Cardinal Ercole Rangoni (1520–1527), a synod was held by his Vicar General, Giandomenico Sigibaldi in 1521.

[23] A diocesan synod was held in Modena on 4–5 September 1565 during the Administratorship of Cardinal Giovanni Morone (1564–1571), in accordance with the decrees of the Council of Trent.

[30] His immediate successor, Bishop Alessandro Rangoni (1628–1640) held diocesan synods on 5–6 November 1631,[31] and his second on 12–14 October 1637.