Communia vulgo denominantur civitates seu castra quae a commune cum potestatibus forensibus continue electis seu designatis una cum consiliis communalibus gubernata sunt. Ista definitio hic quoque asciscitur.
Nota quod communia Istrie numquam omnino libera erunt, sed semper aliquem superiorem recognoscentes qui designabat eorum potestates seu electiones eorum confirmabat et qui iurisdictionem appelationis exercebat.
Ista communia illa sunt:
Commune castri Muglae
Commune civitatis Iustinopolis
Commune castri Isolae
Commune castri Pirani
Commune castri Pinguenti
Commune castri Portularum
Commune castri Bullearum
Commune castri Grisignanae
Commune castri Humagi
Commune civitatis Civitatis Novae alias Emonae nuncupatur
Commune civitatis Parentii
Commune castri Sancti Laurentii
Commune castri Rubinii
Commune castri Duorum Castrorum
Commune civitatis Polae
Commune castri Vallis
Commune castri Dignani
Commune castri Albonae
Nota quod in isto inventario civitates solummodo sedes episcopales nuncupantur.
Euphrasius, the bishop of Poreč, regulates the relations between the Bishopric and the Chapter and prescribes various taxes, including the tithe and the church quartese (a quarter of a tithe) owed by the inhabitants of Poreč and the retainers of church property (forgery composed in the second half of the 12th, or the first half of the 13th century).
Pope Gregory I writes to Callinicus, the Exarch of Italy, regarding a variety of affairs, including the recent military victory over the Slavs and the return of the Church of Koper to the Catholic creed.
Istria as described in the chapters of Cosmography, penned by the anonymous Ravenna Cosmographer (Anonymus Ravennas), including the region's rendition on the famous Peutinger's Map (Tabula Peutingeriana).
Emperor Charlemagne subordinates six episcopal sees to the Church of Aquileia, badly damaged by the incursions of the pagans; late-10th-century forgery.
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.
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.
The eastern borders of the province of Istria (and the Kingdom of Italy / Holy Roman Empire) according to the 10th-century work customarily titled De administrando imperio and ascribed to Eastern Roman Emperor Constantine VII Porphyrogenitus.
Patriarch Rodoald donates Rovinj, a land that was destroyed by the "abominable Slavs", to the Bishopric of Poreč. Forged charter.
Emperor Otto I donates Izola in Istria to the Venetian Vitale Candiano.
Emperor Otto II confirms the purchase of Izola, sold by Vitale Candiano to Patriarch Rodoald of Aquileia.
Emperor Otto II confirms the jurisdictions of the bishops of Poreč and grants them immunities.
Emperor Otto III confirms the donation of six bishoprics to the Patriarchate of Aquileia issued by Charlemagne and donates three abbeys to the same Church.
Pope Sergius IV confirms the jurisdictions of the bishops of Poreč over Rovinj, Dvigrad, and Bale that were disputed by the Aquileian patriarch John.
King Henry II confirms Otto III’s donations of Pazin and Pićan to the Church of Aquileia and donates various jurisdictions in these two places, terrains to both sides of the river Raša, and the port of Plomin.
Upon the petition of the citizens of Koper, who suffered due to their allegiance to the Empire, Emperor Conrad II confirms their possessions, their customary law, immunities, and the freedom to trade in the Empire.
Emperor Conrad II donates Umag to the Bishopric of Novigrad as both an ecclesiastical and temporal possession; 16th-century forgery.
Henry III, King of the Romans, confirms the donations of his predecessors to the Bishopric of Trieste as well as all the immunities and privileges enjoyed by the said Church, including the jurisdiction over Umag and Monfalcone.
Henry IV, King of the Romans, donates properties in Piran and Novigrad in the March of Istria to the monastery of Saint Andrew in Freising under the jurisdiction of the Bishopric of Freising and its bishop Ellenhardus.
Henry IV, King of the Romans, donates properties in Istria to Margrave Ulrich I of Weimar-Orlamünde for his faithful service.
King Henry IV (or III) confirms the jurisdictions and immunities of the Bishopric of Poreč.
Ulrich II Weimar-Orlamünde and his wife Adelaide donate their possessions in the County of Istria to Patriarch Ulrich of Eppenstein and the Church of Aquileia.