King Theodoric orders Anthony, the bishop of Pula, to restitute the rustic possession violently occupied by the bishop's officers to a certain Stephan.
Cassiodorus, as praetorian prefect, remits the collection of tax on wine and corn to the citizens of Concordia, Aquileia and Forum Iulii (Cividale del Friuli) due to a meager harvest; instead, he instructs his tax collector Paul to procure the necessary quantity of wine from Istrians who enjoyed a particularly abundant harvest.
Cassiodorus, as praetorian prefect, informs the provincials of Istria that a part of their due tax will be commuted in kind.
Cassiodorus, as praetorian prefect, sends Lawrence to Istria to examine the harvests and prepare a report of the yields in order for the taxes to be determined.
Cassiodorus, as praetorian prefect, orders the tribunes of the coast to be prepared to transfer the victuals from Istria to Ravenna by sea.
Pope Pelagius I writes to patrician John regarding the detrimental consequences of the schism within the Church (the so-called Three Chapters Controversy), especially concerning the recent election of a schismatic patriarch of Aquileia, urging the Byzantine official not to recognize their authority as they had not been canonically elected.
Pope Pelagius I writes to patrician Valerian, beseeching him to repress the schismatics and support the quest to restore union to the Church.
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).
Pope Pelagius I writes to patrician Valerian, urging him to take action against the schismatic bishops in the ecclesiastical provinces of Milan and Aquileia and support the papal quest to bring back unity to the Church.
Pope Pelagius I writes to patrician Narses, beseeching him to take action against the schismatic bishops, namely the bishop of Fossombrone and the bishops of Liguria, Venetia and Istria.
Pope Pelagius I writes to Charles, the magister militum, regarding the Schism of the Three Chapters and the schismatic bishops.
Gogo, the majordomo of King Childebert II, writes to Grasulf, the Lombard duke of Friuli, proposing an alliance with the Franks, the Papacy, and the Byzantine Empire against their common foes (presumably the Avars and the Slavs, but possibly even the Lombards).
Pope Pelagius II writes to Helias, the patriarch of Aquileia, and all the bishops of Istria, the province whose prelates still persevered in their refusal to condemn the three chapters denounced by the Fifth Ecumenical Council (Constantinople II) of 553, urging them to desist from their schismatic ways and return to the embrace of the Catholic Church.
Romanus, the exarch of Ravenna, writes to King Childebert II of Austrasia, informing him of his triumphs against the Lombards and asking him for military aid; Grasulf, the Lombard duke of Friuli, also supported Romanus' military efforts and he received Romanus' aid in his fight against his enemies in Istria.
Pope Gregory I writes to Severus, the patriarch of Aquileia, requesting on behalf of the emperor (Maurice) that he come to Rome with his clergy and be judged on a synod (for his unwillingness to condemn the Three Chapters and his perseverance in supporting the schism).
The bishops of the ecclesiastical province of Aquileia write to emperor Maurice, beseeching him not to allow their metropolitan, Archbishop Severus of Aquileia, who was forcefully taken to the pope in Rome, to be put on trial and judged by the adversaries of the Three Chapters, that is, the non-schismatic clergy; the bishops expound their viewpoints on the theological controversy, their fealty to the Ecumenical Council of Chalcedon, and why they refuse to denounce the so-called Three Chapters condemned by Emperor Justinian I and the Ecumenical Council of Constantinople in 553.
Emperor Maurice writes to Pope Gregory I, urging him not to treat violently the schismatic bishops of the ecclesiastical province of Aquileia (the "Istrian bishops") and not to compel them to journey to Rome.
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.
Pope Gregory I writes to Maxim, the bishop of Salona, on a variety of matters, including the latest advances of the Slavs and their recent incursions into Italy by way of Istria.
Patriarch John of Aquileia writes to Lombard King Agilulf, complaining that the ill-ordained Candidianus was consecrated as the bishop of Grado by the three Istrian bishops who were violently forced to do so by the “Greeks” (the Romans, that is, the Byzantines), and he beseeches the king not to allow such consecrations to continue following Candidianus' death.
Pope Honorius incites all the bishops of the ecclesiastical province Venetia et Histria to profess disobedience to the deposed patriarch Fortunatus of Grado and to accept subdeacon Primogenius, to whom the pope had already sent the pallium, as their new lawful head of the ecclesiastical province; moreover, the pope promises to open diplomatic negotiations with the Lombard king, with whom the deposed Fortunatus sought refuge, with the goal of restoring all the ecclesiastical goods stolen by the said Fortunatus.
Pope Adrian I writes to Charlemagne, the King of the Franks and the Lombards, beseeching him to direct Duke Marcarius of Friuli to help reinstate the Istrian bishop Maurice – whose eyes have been gouged out by “the most abominable Greeks” – to his bishopric.
King Charlemagne writes to his wife Fastrada, informing her, among other things, of their military successes against the Avars, including the achievements of his “duke of Istria”. This is the first documented mention of a Carolingian official in Istria, officially marking the beginning of a new era of the peninsula’s history.
Emperor Louis the Pious and his son Lothair write to Venerio, the patriarch of Grado, confirming the possessions of his Church, including the Patriarchate's jurisdictions in Istria.
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.