 On 25 January 1074, Pope Gregory VII summoned all the bishops of the ecclesiastical province of Milan, including the bishop of Tortona (whose name is unfortunately not mentioned), to a synod to be held in Rome on the first Sunday of Lent.A diocesan synod was an irregular 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 provincial synod and of the Holy See.