Since the half of the fifth century the most controlled imperial nomenclature had introduced the title of patriarchs for the bishops of great ecclesiastical sees, among which Rome was outstanding. In the case of Aquileia attribution of this title apparently dates back to the age of the Ostrogoth kingdom (493-553), before the Schism of the Three Chapters [scisma tricapitolino]. Since 545 emperor Justinian had juridically restrained this title to five Episcopal sees: Rome, Constantinople, Alexandria, Antioch, Jerusalem. Nevertheless the metropolitan bishop of Aquileia Macedonius (542-557) and his successor Paul [Paolo] (557-569) kept on being titled patriarchs, as evidenced by a letter of pope Pelagius I of the year 559. Due to the isolation following the Schism of the Three Chapters [scisma tricapitolino], it was possible for Aquileia, and subsequently for Grado, to hold such a title, which soon became traditional. After the schism settlement in 698, popes authorized the preservation of this title that in the meanwhile had become merely historical and honorific in the Western Church and therefore could no longer give cause for any jurisdictional claim comparable with the Roman one. But there was left the juridical-institutional conflict between the sees of Aquileia and Grado, each claiming the patriarchal title for itself. In the Frankish Empire milieu the metropolitans having their see in Cividale were named Aquileian patriarchs. In 828 the synod of Mantua acknowledged only these latter being legitimated to use the title of ‘patriarch’. In their strong position before the popes thanks to the Germanic emperors’ support the Aquileian metropolitans of Cividale had therefore their title confirmed. Their opposition against the duchy of Venice, tutoring the see of Grado, was considerably violent. Towards the year 1024 patriarch Poppo [Poppone], who had re-established his see in Aquileia, led a military expedition against Grado, which he esteemed a simple parish, that was set on fire and despoiled of its relics that were hence transferred to Aquileia. With the purpose to please emperor Conrad II in 1027 pope John XIX judged that the patriarch of Aquileia was to be acknowledged as chief and metropolitan of the Churches of Italy and second in dignity only after the Roman see. Though the later recognition of Grado as «caput et metropolis» of «Venetia et Histria» and the brief Aquileian bishop’s demotion to simple «Foroiuliensis episcopus» due to pope Leo IX in 1053, it was an emperor again, Henry IV, who confirmed Aquileia as patriarchal metropolis in 1062 with various properties also in Istria and Friuli; and under such a title patriarchs were definitely invested with the Foroiuliensis ecclesiastical fee by the same Henry IV on April 3rd, 1077.
Introduction and preservation of the title of ‘patriarch’