Bishop Eusebius of Nicomedia (d. AD 341) (Izmit)
Eusebius embraced the false teaching of Arianism while studying in Antioch. After finishing his education, Eusebius became the bishop of Nicomedia and served for twenty years, from 318 to 338. Because Nicomedia was the imperial city of the eastern Roman empire, Eusebius exerted a tremendous amount of influence during the reigns of Licinius (308-324), Constantine (324-337), and Contantius II (337-361). During this time, Eusebius spread Arianism throughout the imperial court and Asia Minor (modern Turkey).
The Ecumenical Church Council convened by Constantine in 325 condemned Arianism, but Eusebius was the primary supporter of Arius and his teaching. In the end, Eusebius signed the Nicene Creed, but declared that he did so with his hand only, and not with his heart. Only a few months after the council, Constantine became angry because of Eusebius’ continued support for Arianism and its supporters. Constantine exiled Eusebius to Gaul (modern France) for three years. In 329, after convincing Constantine that he supported the Nicene Creed, Eusebius was allowed to return as Nicomedia’s bishop. After returning, he consolidated the support of Constantine and his son Constantius II and did everything he could to establish Arianism as the official teaching of the Roman empire.
Because Eusebius was related to the imperial family, he was allowed to baptize Constantine on May 22, 337, just before his death. After Constantine’s death, his son Constantius II replaced bishop Paul with Eusebius, who served as Constantinople’s bishop for three years, from 338 to 341. Although Eusebius died in 341, emperors Constantius II and Valens continued to spread the false teaching of Arianism throughout the church of Asia Minor (modern Turkey)t. It was not until the pro-orthodox reign of emperor Theodosius I that Arianism lost its hold on the eastern Roman church.