Between the half of the sixth and the first years of the following century, in politically very critical conditions, during the passage from the Ostrogothic to Roman-Byzantine dominion (552 ca.) and from the latter to the advent of the Lombard reign (568), on the see of the bishops, and since Paul and later on, of the patriarchs of Aquileia, there followed five personalities who had to defend the ‘fides patrum’ against philo-Monophysite decisions by Justinian and the second ecumenical Council of Constantinople (553). All of them, but with a larger evidence of documents, at least three patriarchs, Paul, Elias [Elia] and Severus, were authors of letters to popes and emperors, and of apologetic documents, which had their replies in letters by popes Pelagius I, Pelagius II and Gregory I, and by emperors. The conflict burst just after the end of the Council of Constantinople, whose decisions were to be obeyed, after long withstanding, also by pope Vigilius; those same decisions had been contrasted by the future pope Pelagius I who had written In defensione trium capitulorum and then, on the contrary, on Justinian’s request, he asked John, ‘magister militum’, to intervene so that the Church of Aquileia retreated its condemnation of the ecumenical council, and to take repressive measures against Paul and other bishops of Liguria, Venetia and Istria that were equally withstanding those decisions, as other Western and African churches. The Church of Aquileia was then ruled by Macedonius (542-557). Both with Macedonius and his successor, Paul, there stood the question about bishops’ ordination: from ancient times Aquileia and Milan were used to mutual consecration, yet pope Pelagius I condemned this praxis for the case of Paul who had been consecrated by the metropolitan bishop of Milan in 557. The synod of Aquileia, where Paul sent a letter to the pope, had confirmed their irremovable attachment to the deliberations of Chalcedonia and their refusal to condemn the Three Chapters [Tre Capitoli]: therefore in his reply, after reminding that no bishop of Aquileia had ever taken part in general councils, against whose decisions no synod could declare themselves, the pope defined the bishop of Aquileia ‘pseudoepiscopus’. In his Vita Martini Venantius Fortunatus defined Paul «pious» and thanked him for convincing to embrace monastic life. Paul the Deacon also refers that Paul had to flee to the island of Grado «secumque omnem suae thesaurum ecclesiae deportavit» for dread of the barbarity of the newcomers into the continent. The title of patriarch, which had been spreading as a token of honour during the sixth century and was forbidden by Justinian in 540, whereas he reserved it to five ‘legitimate’ patriarchs, is confirmed to be used at Aquileia when addressing to Paul in the same letter by Pelagius I: after Paul, it was regularly used by the bishops of Aquileia (and then by the ones of Grado, too) and was de facto accepted by Rome since the eighth century. Paul died in 569 at Grado, where his «sepulchrum usque hodie ibi manet», as the Grado Chronicle reports (rr. 348-349).
For further information see the entry Paolo I, patriarca d’Aquileia written by Sergio Tavano in Nuovo Liruti. Dizionario biografico dei Friulani, 1, Il Medioevo, edited by C. Scalon, Udine, Forum, 2006, 650-652.