Eusebius of Dorylaeum was the 5th-century bishop of Dorylaeum (modern-day Eskişehir, Turkey), who spoke out against dissident teachings, especially those of Nestorius and Eutyches, during the period of Christological controversy. After succeeding in having them expelled from their positions, Eusebius was himself deposed and only reinstated two years later, after which the doctrine in dispute was more precisely defined. Early life Eusebius is unknown before his oppositions to Nestorius and Anasthasius in the mid-420s. He is described as being a lawyer or other non-clergy (a layman) involved with the law or court in Constantinople. In some references, he is described as a rhetor. Opposition to Nestorius and Anastasius In the late 420s the newly appointed patriarch of Constantinople, Nestorius, and a presbyter named Anasthasius (both from Antioch) had been preaching on the Greek word theotókos (“mother of God”) as it is used referring to Mary, mother of Jesus; they were imploring the people that Mary should not be worshiped or referred to as such. Instead, they explained that she should be called christotókos (“mother of Christ”): a symptom of his larger belief that Christ was born a man, and God was dwelling inside or upon him. This quickly drew attention from church officials who disapproved of such a change in terminology regarding Mary, as well as the Christian public. During one sermon by Nestorius on this topic in AD 428 or 429, Eusebius publicly proclaimed that “the eternal Word had submitted to be born a second time,” getting his fellow listeners at the sermon to drown out Nestorius with sympathetic applause. Soon afterwards, a letter was posted in Constantinople that correlated Nestorius’ teachings with that of Paul of Samosata, an heretical figure from the previous century that had also denied or otherwise challenged the divine nature in Christ. This letter was called the Contestatio and is generally attributed to Eusebius of Dorylaeum. Eusebius may have become a priest soon after this incident. First Council of Ephesus (431) Soon after Nestorius’ public opposition from Eusebius came the summoning of a council in Ephesus to settle the problem of his teachings, where Nestorius was ultimately deposed. At this time a presbyter in Constantinople named Eutyches was in alliance with Eusebius of Dorylaeum in opposition to Nestorius, but it is unclear whether either played a major role in the proceedings of the council beyond accusation, which was largely directed by Cyril of Alexandria.