EUSEBIO of NICOMEDIA. — He was first bishop of Berito (Beyrouth), from which around 318 he had himself transferred to the far more important see of Nicomedia, the imperial residence. A master of intrigue, he insinuated himself into the court of Licinius and of his wife Costanzo, Constantine’s sister. He had been Arius’s companion at the school of Luciano of Antioch and always remained his friend. When Alessandro of Alexandria condemned the heretic, E. gave him shelter and took up his defense, provoking Alessandro’s protests (Socrate, Hist. eccl., I, 6).
At the Council of Niera he presented a formula of such rigid Arianism that it was immediately rejected as blasphemous. Finally, he agreed to sign the consistory formula. But three months later Costantino exiled him to Gaul. When, in 328, at the urging of his sister Costanza, he recalled him, he unwittingly gave the anti-Nicene reaction a leader so able and active that subsequently the followers of Arius would ordinarily be designated in the sources by the name of Eusebians. E. set himself two objectives: to bring about the downfall of the champions of the Nicene Council and to rehabilitate Arius. Indeed, in 330 he obtained the deposition of Eustasio of Antioch and in 332 the reconciliation of Arius with Costantino, though not with Atanasio of Alexandria, whose condemnation he brought about at the Council of Tyre (335). The following year the same fate befell Marcello of Arcina. Only the reinstatement of Arius remained. Since E. could not obtain his admission into the Church of Alexandria, he worked to have him accepted into that of Constantinople; but the heretic died on the eve of his triumph. E. nevertheless continued along his path. In May 337 he baptized the dying Costantino at Nicomedia. Having also won the favor of his successor Costanzo, in 338 he obtained, contrary to the prescriptions of the Nicene Council (can. 15), his replacement of the bishop Paolo in the see of Constantinople, whom he had caused to be deposed. From there he was able to direct the struggle against the Nicene Council with still greater success. He installed a Gregorio of Cappadocia in the see of Alexandria, forcing Atanasio to flee to Rome. Pope Giulio protested (340). The Council in Encaenias (Antioch, 341), maneuvered by E., rudely rejected the protest, denying the Pope’s competence. Shortly afterward, toward the end of 341 or the beginning of 342, E. died. Arianism owes it to him that it was not extinguished immediately, but became a danger to the Church that lasted so long.
(fol. Pont, comm. arch. sacra)