On the cathedra of Aquileia after bishop Fortunatianus [Fortunaziano], around the year 368, there followed Valerianus, who inaugurated a new theological and pastoral line of a more Nicene observance: it is the moment when Aquileia acquires a prominent role among the Churches of northern Italy, including Milan, and over the ones between the Adriatic sea and the Danube, too. Valerianus’ pastoral activity is for the first time evidenced during his participation in the Roman council summoned by pope Damasus between 369 and 372 to put the Christian West in order again after the crisis caused by the Arianism, and to withstand theological news. Maybe it was also due to its vigorous action for orthodoxy, as well as for its geographical location, that Aquileia was chosen as place to house a western council in September 381. This council, which was itself of modest proportions, acquires an exceptional value to our glance because among the councils on the hoary Arian controversy it is the only one the official acts of which have come to us nearly unabridged: these allow step-by-step to follow the vivid, sometimes dramatic, progress of the discussion. The council of 32 bishops presided by Valerianus and led by Ambrose started their works on 3 September 381 and, as to the properly called procedural part, accomplished them in the evening of that same day with the condemnation of the two accused bishops, Palladius of ‘Ratiaria’ and Secondianus of ‘Singidunum’, the most representative exponents of the declining Illyrian Arianism. At that time the Church of Aquileia was experiencing its best opportunity, when near the Episcopal centre there had its bloom a remarkable seminary that was organized according a monastic model, perhaps due to the enthusiasm the presence of St. Athanasius provoked in the fervent community in 345, and inspired to the Alexandrine idea of harmony between faith and classical culture.
For further information see the entry Valeriano, vescovo di Aquileia written by Giuseppe Cuscito, in Nuovo Liruti, Dizionario biografico dei Friulani, 1, Il Medioevo, edited by C. Scalon, Udine, Forum, 2006, 887-889.