Bishop of Nicomedia; died 341 A pupil of Lucian of Antioch, Eusebius was the constant defender of Arius and exerted himself in every way to accomplish the downfall of Saint Athanasius and the other bishops opposed to the heresiarch. He succeeded in placing his tools in the sees of the deposed bishops of Alexandria and Antioch, and having denied the jurisdiction of Rome usurped the See of Constantinople and induced the young Emperor Constantius to enforce his policy.