Constantine, Athanasius and Eusebius of Caesaria: Central Figures of the First Council of Nicea

The fourth century was a pivotal era for Christianity, marked by theological debates, imperial politics, and the foundational formulations of doctrine. At the heart of this period stood three towering figures—Athanasius, Emperor Constantine the Great, and Eusebius of Caesarea. Each played a distinct role in the turbulent events surrounding the First Council of Nicaea and the Nicene Creed, and each were important figures in the early church for other reasons as well.

As discussed in the June e-newsletter article, the controversy that prompted the Council of Nicaea centered on Arianism, a theological position named after Arius, a presbyter from Alexandria. Arius taught that the Son of God was not co-eternal with the Father, asserting, “There was a time when he was not.” This view implied that Christ was a created being, subordinate to the Father.

Constantine: The First Christian Emperor

Constantine, the first Roman emperor to embrace Christianity was born in Illyria, a region in the Balkans. around A.D. 280. We know little about his early years. But by the time Constantine was 31, he was in line to become emperor of the western empire.

Sources record that Constantine experienced a dramatic series of events surrounding the Battle of Milvian Bridge, which took place on October 28, 312. Constantine reportedly saw a vision of “a cross-shaped trophy formed from light” above the sun at midday and a text attached to it which said, “By this conquer.” Afterwards, Constantine was advised in a dream to mark the heavenly sign of God on the shields of his soldiers and then engage in battle. Constantine did as he was commanded and ordered his soldiers to mark their shields with the now famous Chi-Rho. With his army’s shields marked with this sign, Constantine vanquished his foe Maxentius in the battle and became the undisputed emperor of the western Roman Empire.

Constantine was not converted to Christianity by these events. But as he became emperor, Christianity clearly had taken hold of many of his thoughts. Shortly thereafter in 313, Constantine and Licinius, the emperor of the eastern portion of the empire, issued the Edict of Milan, which granted tolerance to Christianity and all other religions. Constantine still did not declare himself a Christian. In fact, most influential people in the empire had not been converted to Christianity and still participated in traditional Romas religion. But the history of Christianity had been changed. The era of Christian persecution was all but gone. An era of rapid Christian ascendency had begun.

After he became the emperor of both the eastern and western portions of the empire, Constantine began to embrace Christianity further. Some historians argue that he did so for political purposes, as Christianity was more wide-spread in the east than in the west. Certainly, he did view the Arian controversy not just as a theological dispute but as a threat to the unity of the empire. Seeking to consolidate both his rule and the Christian Church, he convened the Council of Nicaea with the goal of achieving consensus and peace among Christian leaders.

In addition to becoming involved in church affairs, Constantine supported the church financially, had a number of churches built, promoted Christians to high-ranking offices, returned property confiscated during the Great Persecution of Diocletian, endowed the church with land and other wealth, and commissioned the production of many bibles. Between 324 and 330, Constantine built a new city – a “new Rome” – that would be named Constantinople for him. Unlike “old” Rome, Constantinople was built using much Christian architecture, contained churches and did not include temples from other religions.

Eusebius: The Historian and the Compromiser

Although the Council of Nicea condemned Arianism as heresy and adopted the Nicene Creed affirming Trinitarianism, many bishops of the Eastern empire were unwilling to abandon the Arian position. One of the most influential figures standing in opposition to the creed and the results of the council was Eusebius of Caesarea.

Eusebius of Caesaria was a highly respected scholar and is regarded as the “Father of Church History.” Among other things, he wrote Ecclesiastical History. This ten volume work was a chronological account of the development of early Christianity from the 1st century to the 4th century. It was the first world history written from a Christian perspective. Almost all of what we know of the Council of Nicea comes from the writings of Eusebius of Caesaria. He also wrote The Life of Constantine.

At Nicea, Eusebius of Caesaria sympathized with Arius. He eventually signed the Nicene Creed adopted at the council, probably due to pressure from Constantine. After the council, however, he remained an important supporter of Arius. Although not necessarily an Arian in the strictest theological sense, Eusebius of Caesaria advocated for a more moderate position that interpreted some of the Nicene creed terminology so that it was not directly contrary to Arianism. He advocated a middle ground that sought to include moderate Arians within the church’s fold. He was less concerned with Arius’s heresy than the threat of disunity in the church.

Eusebius of Caesaria and others persuaded Constantine to take a more moderate view after the council had concluded. He was among the first to urge Constantine to reinstate Arius after he was anathematized. He remained critical of and opposed the orthodoxy of Athanasius.

Athanasius: The Unyielding Defender of Trinitarianism

Athanasius was still a young deacon at the time of the Council of Nicea, although he served as the spokesperson of Bishop Alexander of Alexandria during the proceedings. Shortly after the council, Athanasius succeeded Alexander as Bishop of Alexandia.

Athanasius opposed the efforts of Eusebius of Caesaria and others to cause the church to take a more moderate position towards Arians. He steadfastly refused to reinstate Arius in the church or tolerate his supporters. This provoked resistance from pro-Arian factions, particularly Eusebius of Nicomedia (a powerful pro-Arian Bishop not to be mistaken for Eusebius of Caesaria), who became the political architect of the anti-Nicene movement during Constantine’s later reign and the reign of Constantius II.

Eusebius of Nicomedia orchestrated a campaign of opposition against Athanasius, accusing him of various crimes—including violence, heresy, and even interfering with the grain supply of Constantinople. Though many of these accusations were fabricated or exaggerated, they served as pretexts for Athanasius’s exile. Under pressure from Eusebius of Nicomedia and others, Constantine convened a synod at Tyre to investigate accusations against Athanasius. The council, dominated by Arians and semi-Arians and which included Eusebius of Caesaria, deposed Athanasius. Soon after, Constantine exiled Athanasius to Trier.

Near the end of his reign, Constantine seems to have reconsidered his position again. He allowed Athanasius to return to Alexandria in 337. But the tensions and dispute in the church were unresolved. Athanasius was exiled four additional times by different emperors under the influence of Eusebius of Nicomedia and other pro-Arians. While in exile, Athanasius spent most of his time writing, mostly to defend Trinitarianism. He fervently and repeatedly disputed every argument raised by the Arians to promote their views. He took on pagan and Jewish opposition as well. One of his most lasting contributions is his Life of St. Antony, a “best seller” of early Christianity that helped to shape the Christian ideal of monasticism by making early Christians aware of the story of this Egyptian monk.

During his first year back in Alexandria following his final period of exile, Athanasius sent an annual “festal” letter to the churches in his diocese. In this letter, Athanasius listed what he believed were the writings that should constitute the New Testament. “In these [27 writings] alone the teaching of godliness is proclaimed,” he wrote. “No one may add to them, and nothing may be taken away from them.” Though other lists had been and would be proposed, Athanasius’s list was the list eventually adopted by the Church as the canon of the New Testament.

Conclusion

Constantine died in 337, Eusebius of Caesaria died in 340 and Athanasius died in 373. None of them would live to see the ultimate triumph of Trinitarianism over Arianism in 380 and 381 during the reign of Emperor Theodosius I. This triumph was a pivotal event in Christian history, with profound theological consequences. Trinitarianism affirmed that Jesus Christ is fully God, co-eternal and consubstantial with the Father. It upheld the belief that God Himself entered human history.