Venerius, patriarcha Gradensis

Emperor Louis the Pious and his son Lothar write to Venerius, the patriarch of Grado, confirming the possessions of his Church, including the Patriarchate's jurisdictions in Istria.

Louis the Pious and his son Lothar instruct Patriarch Venerius of Grado to go to Rome again to settle his dispute with the Patriarch Maxentius of Aquileia before the Pope and their messengers, despite the fact that Maxentius failed to attend the first meeting, causing Venerius to return home without any resolution.

The decrees of the Synod of Mantua: the long conflict between the patriarchs of Grado and Aquileia over the metropolitan jurisdiction over Istrian bishoprics is settled in favor of the Aquileian Church.

Patriarch Venerius writes to Pope Gregory IV, imploring his assistance in resolving disputes regarding the metropolitan jurisdiction over Istrian bishoprics, granted by the Synod of Mantua (doc. 827_SM) to his adversary Maxentius, the patriarch of Aquileia, and expressing confidence in the Pope’s judgment and authority.

Pope Sergius II writes to Andrew, the patriarch of Aquileia, addressing his ongoing dispute with Venerius, the patriarch of Grado, urging patience, suggesting the convening of a general synod to address these issues, and emphasizing the need for imperial authority to finally put an end to this dispute between the two ecclesiastical sees.