 On 25 March 901, the Emperor Louis III issued a charter in which he confirmed Bishop Adelbertus and his successors in all their rights and possessions as bishops of Bergamo.The diploma specially mentions the church of S. Alessandro in Fara, which Bishop John converted from the Arian heresy to the Catholic faith.On 23 June 904 King Berengar I of Italy ordered Bishop Adelbertus and the citizens of Bergamo to rebuild the walls which had been destroyed during the incursion of the Hungarians.