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 and fixing the tributes due to the Church of Poreč, forged in the first half of the 13th century (before 1222).
Maximian, the bishop of Ravenna, endows the monastery of St. Andrew and the church of St. Mary in Pula.
Emperor Justinian I issues a pragmatic sanction regulating the administration of the newly conquered Italy (the so-called sanctio pragmatica pro petitione Vigilii or epitome constitutionum Iustiniani de reformanda Italia).
Pope Pelagius II confirms Grado as the new metropolitan see of the ecclesiastical province of Venetia et Histria; 11th-century forgery.
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).
King Charlemagne bestows to the Church of Aquileia the right to canonical election of their patriarchs (that nonetheless requires royal confirmation) and exempts it from public taxes such as the tithes, the grazing fees for livestock sent to graze in Istria, and war taxes (lodgings and provisions for the army) unless the royal military is forced to pass through Friuli and the Treviso region.
King Charlemagne confirms the possessions of the Church of Aquileia and grants it immunities.
Emperor Charlemagne subordinates six episcopal sees to the Church of Aquileia, badly damaged by the incursions of the pagans; late-10th-century forgery.
Emperor Charlemagne bestows immunities upon the Church of Grado due to the special services and merits of its incumbent Patriarch Fortunatus II.
Emperor Charlemagne exempts the four ships of Fortunatus II, "the patriarch of the Venetians and Istrians," from all the tolls.
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.
Emperor Louis the Pious promises to Patriarch Fortunatus II and to all the Istrians that their right to elect their own patriarchs, bishops, abbots, tribunes, and other officials will be respected and that the rulings of the judicial assembly (placitum) held by Rižana will be upheld.
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 Lothair I confirms the immunities enjoyed by the Church of Aquileia and its right to canonically elect their patriarchs.
The first pact between the Western Roman Empire, represented by Emperor Lothair I, and the Duchy of Venice, represented by Doge Pietro Tradonico, sanctioning mutual aid in campaigns against the Slavs and defining the rights over the use of land as well as the modalities of justice administration. This is the first "international" treaty in which Venice partook as an autonomous polity, independent of the Byzantine Empire.
The last will and testament of a woman from Trieste calling herself "Maru, the handmaiden of God" (Maru ancilla Dei).
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 Lothair I to the Patriarchate of Aquileia regarding the dispute with the Patriarchate of Grado that was settled at the Synod of Mantua in 827: 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.
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.
King Berengar I donates two forts, the Vermes (Beram in Istria ?), to the Bishopric of Trieste (10th- or 11th-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.
Hugh of Arles and his son Lothair II, kings of Italy, donate Muggia to the Patriarchate of Aquileia.
Due to fair treatment and protection, the city of Koper, represented by a locopositus, scabini, the protector of the people (advocatus totius populi) and many others, freely promise an annual tribute of one hundred amphorae of wine to Venice, to be paid every year within ten days of the harvest, and protection to all Venetians.
Thanks to the mediation of Marino, the patriarch of Grado, Lupus II, the patriarch of Aquileia, manages to reach a peace accord with Venice, represented by Doge Pietro III Candiano, but only under the condition that all the hostilities directed against Grado immediately stop and that the patriarch promises to inform Venice of any hostile plans directed against it.