Euphrasius, the bishop of Poreč, imposes a variety of taxes, including the tithe and the ecclesiastical quartese (the quarter of the tithe) on the citizens of his bishopric. The document aimed at proving the episcopal lordship over the city of Poreč, forged in the first half of the 13th century.
Pope Pelagius I writes to a patrician John on the detrimental effects of the schism in the Church (the so-called Three Chapters Controversy), singling out Bishop Euphrasius as a particularly depraved schismatic and advising the patrician to repress the schismatics in the province of Aquileia (that is, the region Venetia et Histria).
The acts of the synod of Grado, heavily interpolated by later falsifications, by which the bishops of the ecclesiastical province of Aquileia remain faithful to the Catholic creed as decreed by the Ecumenical Councils of Chalcedon (451), Ephesus (431), Constantinople I (381) and Nicaea (325), refusing to denounce the Three Chapters condemned by the Second Ecumenical Council of Constantinople (552).
Following the death of Aquileian patriarch Helias, his successor, Patriarch Severus, together with three other bishops (including the bishop of Poreč, John) are imprisoned in Ravenna by the Byzantine exarch Smaragdus; in order to buy their freedom, the prelates agree to condemn the Three Chapters and reunite with Rome, a move that greatly angers other bishops in the ecclesiastical province of Aquileia. Finally, a synod is held in Marano (591) whereby Patriarch Severus is forced to formally acknowledge the error of his ways in supporting the condemnation of the Three Chapters (narrative accounts from Paul the Deacon's History of the Lombards).
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 Rodoald donates Rovinj, a land that was destroyed by the "abominable Slavs", to the Bishopric of Poreč. Forged charter.
Emperor Otto II confirms the jurisdictions of the bishops of Poreč and grants them immunities.
A public placitum held in front of the Istrian count Werihen whereby the dispute between the Bishopric of Poreč, represented by Bishop Andrew, and a Bertha, a widow of a Cadoloh, regarding the latter's fiscal obligations towards the Church of Poreč (herbatico and glandatico) is judged in Bertha's favor.
Pope Sergius IV confirms the jurisdictions of the bishops of Poreč over Rovinj, Dvigrad, and Bale that were disputed by the Aquileian patriarch John.
Engelmar, the bishop of Poreč, donates the monastery of Saint Cassian in Poreč to the monastery of Archangel Michael in Pula.
Azica, the daughter of count Wezelin and Williburga, donates properties to the monastery of Saint Mary and Archangel Michael in Lim bay. 14th century forgery.
Countess Williburga, the mother of Azica, confirms her daughters donation and donates even more properties to the monastery of Saint Mary and Saint Michael in Lim. 15th century forgery.
The decision of Henry III's royal court regarding the tithes from the territories of Saint Michael's monastery in Lim bay. 15th century forgery.
Megingaudus, the bishop of Pula, donates a property to the monastery of Saint Michael, witnessed by "Istrian margrave Ulrich".
King Henry IV confirms the jurisdictions and immunities enjoyed by the Bishopric of Poreč.
Henry IV, King of the Romans, donates imperial rights over the Bishopric of Poreč, including the right to appoint and invest its bishops, to the Patriarchate of Aquileia and its patriarch Henry.
Pope Alexander III confirms the spiritual and secular jurisdictions of the bishops of Poreč.
Wolfger, the patriarch of Aquileia and margrave of Istria, confirms the boundaries of the territories under the jurisdictions of the bishops of Poreč. A Forgery drawn up by the chancery of Boniface, the bishop of Poreč (1282 - 1305).