Little is known about the Christian community of Aquileia under the successors of bishop Theodore [Teodoro], Agapitus and Benedictus, until the election of Fortunatianus, of African origin, which is to date to a year not much before 343, in the stormy period of the Arian controversy. About Fortunatianus of Aquileia it is known that he took part in the council of Sardica and sided with Athanasius, the champion of the Nicene faith. When the council closed, Fortunatianus went back to Aquileia, where some months later Athanasius arrived, too. Here the patriarch of Alexandria celebrated Easter in 345 together with Fortunatianus and in the presence of Constans, emperor of the West and his patron. Meanwhile Constantius, who had remained the uncontested leader of the West, was skilfully conquered back to Arianism, while Arian bishops produced again new charges against Athanasius. Therefore pope Liberius deemed it necessary to summon a new general council to put an order to the upset Church and in 353 sent legates to Constantius to solicit the calling of a council at Aquileia, surely because of the trust bishop Fortunatianus inspired to Liberius. On the contrary the council was held at Arles under the influence of Ursacius and Valens, emissaries of Arianism for the West. In the Council of Milan of 355 Constantius insisted absolutely on Athanasius’ condemnation and those who did not give in, as Dionysius of Milan himself, were exiled; on the other hand, under the pressure of threatens and with the majority of the bishops, albeit with some kind of withstanding, Fortunatianus subscribed Athanasius’ condemnation. Fortunatianus, inclined to theological compromise just to achieve religious pacification, appeared to be eager to comply with Constantius’ intentions. Fortunatianus was to be again the author of pope Liberius’ presumable fall; according to Jerome’s witness, he was to advise Liberius, while going into exile, not to resist. It is however certain that Fortunatianus fell into line with the anti-Athanasian party, and most likely he supported the semi-Arian cause, to great disappointment of the hopes Liberius had placed on him. Apart from the implications in the controversies on Arianism, since he also recognized the needs of the rural suburban world, in a brief and rustic language and in an ordered form Fortunatianus wrote some Commentaries, mentioned by Jerome, only some fragments of which unfortunately have arrived to us. Yet Jerome had to have a direct knowledge of them, since in his introduction to the Gospel according Matthew he testifies that he had read the booklets by Hilary of Poitiers, Victorinus of Poetovium and Fortunatianus, and adds: «and though I myself did scarcely take from them, something worth of memory could be written thereon».
For further information see the entry Fortunaziano, vescovo di Aquileia written by Giuseppe Cuscito, in Nuovo Liruti, Dizionario biografico dei Friulani, 1, Il Medioevo, edited by C. Scalon, Udine, Forum, 2006, 338-343.