Vol. 2: A 804 usque ad 1077

The Plea of Rižana (Placitum Rizianense): The representatives of Istrian towns and cities present their grievances to counts Aio and Cadulus, the envoys of the Roman emperor Charlesmagne, in an official placitum held by the river Rižana in the district of Koper.

Pope Leo III writes to Emperor Charlemagne regarding the situation of Fortunatus, the patriarch of Grado who had been exiled from his see by the Venetians and "the Greeks". The pope agrees that the Church of Pula should be bestowed upon Patriarch Fortunatus as his new seat.

Emperor Louis the Pious informs Patriarch Fortunatus II of Grado and the faithful of the province of Istria that, at their request, he confirms the free election of the patriarch, bishops, abbots, tribunes and other authorities, that in the event of breach of faith, quarrels and oppression of the poor, the legal judgment awaits them and that violators of the Placitum of Rižana (doc. 804_PR) will be subject to the prescribed penance.

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.

Emperor Louis the Pious deposes several marcher officials – including Baldric, the duke of Friuli – from their offices due to their military impotence. As a result of Baldric’s deposition, the March of Friuli – which included Istria – is divided into four counties governed by their respective counts.

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.

The last will and testament of Doge Giustiniano Particiaco, ordering, among other things, the construction of a new church next to the ducal palace where the newly procured remains of St. Mark the Evangelist ought to be deposited.

Emperor Lothair I confirms the immunities enjoyed by the Church of Aquileia and its right to canonically elect their patriarchs.

The first pact between the Venetian neighbors in the Kingdom of Italy, represented by Emperor Lothar I, and the Duchy of Venice, represented by Doge Pietro Tradonico, sanctioning mutual aid in campaigns against the Slavs, defining the rights over the use of land and numerous aspects related to trade as well as the modalities of justice administration.

Emperor Lothar I confirms the Venetian possessions in the Empire.

A poem composed in response to the Synod of Mantua (6^th of June, 827), arguing that Aquileia, the old metropolitan see of the ecclesiastical province Venetia et Histria, was so thoroughly destroyed by barbarians (Attila, the Avars, Lombards and Goths) that it was never rebuilt; thus, the metropolitan see transferred to "the Venetians" and Aquileia was demoted to a status of a mere parish.

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.

The last will and testament of a woman from Trieste calling herself "Maru, the handmaiden of God" (Maru ancilla Dei).

Pope Leo IV writes to Victor, the patriarch of Grado, conferring upon him the pallium.

Emperor Louis II assumes under his protection the monastery of St. Michael in Diliano and its abbot Felmo, bestowing upon the monastery immunities and the right of free election of its abbots.

Emperor Louis II confirms the charter of Lothar I to the Patriarchate of Aquileia regarding the dispute with the Patriarchate of Grado that was settled at the Synod of Mantua in 827 (doc. 827_SM): the patriarchs of Aquileia are to enjoy the metropolitan jurisdiction over all the Istrian bishoprics.

Emperor Louis II confirms to St. Michael's monastery in Diliano and abbot Felmo the right to have two lay advocates - the brothers Petronasius and Talasius - to defend their rights.

Pope Benedict III writes to Vitalis, the patriarch of Grado, conferring upon him the pallium.

Venice, represented by Doge Orso I Participazio, and the Patriarchate of Aquileia, represented by Patriarch Walpert, sign a treaty according to which the Venetian Doge agrees not to block the Aquileian port Pylum, but only under the condition that the patriarch stops with all the hostilities directed against the Church of Grado and exempts the Venetians from all the tolls on his territories, according to the old customs.

Pope Sergius III writes to John, the bishop of Pula, informing him of Archbishop of Ravenna John XI's complaints against Count Albuin, who unlawfully alienated the possessions of the Church of Ravenna in Istria, and asking him to personally convey to the Count that he must return these possessions under the threat of excommunication and that King Berengar I will not be crowned emperor until he grants Albuin’s March (of Istria or of Friuli) to someone better.

Archbishop John XI of Ravenna writes to Bishop John of Pula regarding the pope's admonition of Count Albuin who had alienated some goods of the Ravennite Church in Istria.

King Berengar I donates two forts, the Vermes (Beram in Istria ?), to the Bishopric of Trieste (10^th- or 11^th-century forgery).

King Hugo donates Sipar, Umag, and Monfalcone to Radald, the bishop of Trieste, and places the Bishopric of Trieste under his royal protection; a forged charter.