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).
Due to fair treatment and continuous 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 gift of one hundred amphorae of wine to the Venetian Doge Pietro II Candiano, to be paid every year within ten days of the harvest, guarantee protection to all Venetians in their city, and prompt debt recovery.
Following a dispute between the Venetians and Istrians, one that resulted in the embargo on all trading between Istria and Venice, Margrave Winther, together with the people and the bishops of Istria, promise to cease all hostilities towards the Venetians, not to usurp or occupy the properties of the Patriarchate of Grado or Venetian bishoprics in the region, to regularly take cognizance of and adjudicate the complaints lodged by the Venetians against defaulting debtors from Istria, to abolish all the newly instituted duties and only charge the customary fees of a docking tax and a market fee, and to promptly inform the Venetians in case the king of Italy plans any offensive against them so that they could safely repatriate.
Emperor Otto I donates Izola in Istria to the Venetian Vitale Candiano.
Emperor Otto II confirms to Patriarch Vitalis of Grado and the bishops subject to him the jurisdictions, immunities, and other rights of their churches.
Emperor Otto II confirms the purchase of Izola, sold by Vitale Candiano to Patriarch Rodoald of Aquileia.
The city of Koper renews its pact of fealty to the doge and the city of Venice, promising the security of all Venetians in their city, the remission of duties of transport and commerce, the payment of the customary tribute of one hundred amphorae of wine every year, judicial autonomy, perpetual peace and alliance even in case of war against other Istrian communities.
A public placitum held in front of 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 (herbaticum and glandaticum) is judged in Bertha's favor.
Pope John XIX confirms the possessions of the Patriarchate of Grado.
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.
Following the Synod of Rome, convened to resolve the recently rekindled conflict between the patriarchs of Aquileia and Grado, Pope Benedict IX writes to Urso, the patriarch of Grado, informing him of the Synod’s decision to support the cause of his church against the Aquileian Patriarch Poppo, who had recently launched a second military invasion of Grado before his untimely death; the pope confirms the metropolitan status together with the ecclesiastical and secular jurisdictions of the Patriarchate of Grado, dubbed “New Aquileia” for the very first time in an authentic papal document.
King Henry IV confirms the rights and possessions enjoyed by the Patriarchate of Aquileia, especially the parish (!) of Grado, bestowed upon the Patriarchate by Henry's predecessors and the Holy See.
Doge Domenico Selvo confirms the donation of various tributes and incomes to the Patriarchate of Grado, originally donated by his predecessor Doge Domenico I Contarini.
The people of Koper and Izola swear an oath of fealty to the doge and the Commune of Venice, promising to arm one galley whenever Venice would embark on a military campaign with fifteen or more galleys, military aid for any Venetian military endeavor in the Adriatic, in the zone between Dubrovnik, Venice, and Ancona, guaranteeing the safety of all the Venetians in their city, and promising to observe the same ducal laws on grain trade as Venetians.
Pope Alexander III confirms the metropolitan jurisdictions of the incumbent Aquileian patriarch, institutes a new suffragan bishopric in Koper, grants him the pallium, and corroborates all the possessions and titles of the Aquileian Church, including the "County, the March, the Duchy," the regalian rights and imperial privileges.
In response to the plea of the citizens of Koper, Doge Orio Mastropiero and the Commune of Venice issue a privilege to Koper, constituting it the only licensed port for salt trade in entire Istria, from Pula to Grado, and granting it a galley by which the citizens of Koper are to oversee the salt trade along the western coast of Istria; the privilege is accorded for twenty-nine years.
The Commune of Koper, represented by the podestà and three consuls, endows the Bishopric of Koper with four villages – Lopar, Padna, Brič and Srmin –, a thousand vineyards, and with the oil tithes of the entire city, forbidding the bishops of Koper to ever enfeoff or otherwise alienate the endowed rights and possessions.
The Commune of Koper issues a decree according to which all who hold vineyards from the Bishopric and fail to pay their dues are to lose these vineyards, while those neglecting oil tithe payments to the Bishopric must render double the owed amount.
Faced with the might of the Venetian navy and the crusading army on their way to Constantinople, the people of Trieste ask forgiveness from Doge Enrico Dandolo for their past transgressions, and promise fealty to the doge and the Commune of Venice, guaranteeing the safety and duty-free trading for the Venetians throughout their jurisdictions, aid in combating piracy in the zone from Rovinj northward, a tribute of fifty urns of wine paid yearly on St. Martin’s feast day and transported to the ducal palace in Venice, and generally to perform all the duties promised by other Istrian communities.
Nicolò Cocco, podestà of Koper, in agreement with the Major and Minor civic councils and by the authority of the entire Commune, appoints Emery Spandinuces as authorized representative of the Commune in the dispute between the Commune of Koper and the Monastery of St. Mary of Aquileia; Emery is authorized to elect arbitrators and mediators, and to give and receive security for the arbitration settlement agreed in writing between the podestà of Koper and the abbess of St. Mary’s monastery.
Answering the pleas of Aquileian Patriarch Berthold, Emperor Frederick II proclaims and ratifies the verdict of the imperial princes gathered at the Diet of Ravenna, confirming the secular rights and prerogatives of Aquileian patriarchs and forbidding the election of rectors and the exercise of regalian rights to the subjected urban communities, especially to the Istrian cities of Koper, Poreč, and Pula.
Emperor Frederick II confirms the treaty signed between Aquileian Patriarch Berthold V and the Commune of Koper.
Count Maynard III of Gorizia promulgates an arbitrational sentence in a dispute between Aquileian Patriarch Berthold V and the Commune of Koper regarding the elections of podestàs, the prerogatives of the appointed gastalds and the administration of criminal justice, fines above a hundred bezants and the patriarch’s right to emend the local statute.
Roman king Conrad IV orders Berthold, the margrave of Vohburg-Hohenburg, to explain to the podestà of Koper, Andrea Zeno, and to the Capodistrians under his authority, how the Margraviate of Istria is an imperial land bestowed unto the late Aquileian Patriarch Berthold V of Andechs by the king’s father (Emperor Frederick II), but now, with the patriarch’s death, the Empire can again freely dispose with the Margraviate and therefore, the citizens of Koper should not swear any fealty to the newly elected Aquileian Patriarch Gregory of Montelongo, but persevere in their allegiance to the Empire.