 The two senior Canons were to be the Theologus and the Penitentiarius, in accordance with the decrees of the Council of Trent.In 1920, the diocese of Guastalla had 26 parishes, 58 other churches and chapels, 76 diocesan priests, and 25 students in the seminary.In 1980, it had 30 parishes, 47 diocesan priests, and 3 priests belonging to Religious Orders.