Constantine, Arius, and Istanbul

On the occasion of the 1700th anniversary of the Council of Nicaea (Nicomedia), the influence of the Unitarian (Muwahhid) thought within Christianity, led by the Libyan cleric Arius, continued even after Arius’s death in 336. Whether Constantinus (Constantine), the founding leader of Istanbul (Constantinople), who was still attached to the pagan faith during the Council of Nicaea, became a Christian and, if so, to which denomination he adhered, has been a matter of debate for centuries.

Constantinus was neither a scholar nor particularly devout; he spent his life as a soldier. Yet, he made his mark in history as one of the most renowned Roman emperors. He succeeded in unifying the Roman Empire under a single centre. He re-established Roman authority across vast territories stretching from the British Isles to Iraq, the Maghreb, and Germany. He was the one who rebuilt the empire. He constructed the city of “Constantinople” (Istanbul), named after himself, as the capital. This city became the centre of both the Eastern and Western Roman Empires. There had never been such a figure in Roman history; historians compared him to Caesar and Napoleon.

Constantine’s legacy is not limited to his military and political achievements; his stance on religious matters also defined his historical role. During the Council of Nicaea, which he convened to unify the Christian denominations, the emperor—still committed to paganism—supported the doctrine of the Trinity due to his affinity with pagan thought at the time. In doing so, he paved the way for a process considered a turning point in Christian history. Up to that point, Christianity had been represented by a Unitarian understanding that simply believed in God. It was precisely at this juncture that history took a different course.

Muslim historians refer to groups among Christians who held beliefs close to those of Islam. These communities viewed Jesus not as God, but as a servant and messenger of Allah. During the era of Islam’s expansion, Muslims encountered many Christians in Anatolia, the Maghreb, and Andalusia who belonged to the sect of Arius. They recognised that these Christians were close to Islam. Their views were clear: “Jesus is a servant, the Messenger of Allah; He is the word and spirit created by Allah, not the son of Allah.”

After the Council of Nicaea, Constantine began to draw closer to the ideas of Arius. He recalled Arius and his followers from exile and allowed them space to spread their views. For this reason, church leaders who supported the Trinity grew hostile toward him. According to historians, his mother Helena also kept him close to the Arians. Their views appeared more reasonable and closer to the truth.

Thus began a conflict within the Christian world that would last for many years. The struggle between supporters of the Trinity and defenders of Arius became central to Christian history. The decisions of the Council of Nicaea in 328 marked the beginning of this transformation. Three years after the council, Helena passed away; Constantine, however, remained on the throne.

 

After Helena’s death, the powerful priests of the church gained the upper hand. Arius’s followers were pushed into the background. However, Arius’s views continued to resonate among the people. This situation forced church leaders to make new decisions. The renowned historian Mark Nixon states: “Constantine and his successors had placed the ornaments and splendour of life into the hands of the church leaders. Those leaders, in turn, went to extremes in deceiving the people and spreading the Trinity.”

Constantine was not officially regarded as a Christian until he was baptised shortly before his death. For this reason, historians have disagreed over whether he was a sincere Christian. Some argue that he accepted Christianity for political reasons, while others maintain that he later embraced Unitarian belief and came to faith under the influence of his mother Helena.

 

Constantine became the first emperor to grant Christians freedom of worship through the Edict of Milan. Christians, who had previously faced persecution, gained their freedom during his reign. This development is considered a turning point in Christian history. However, politics had a significant influence on Constantine’s religious choices. He sought to merge Christianity with the interests of the empire. As the famous philosopher Nietzsche said: “The West crucified Jesus in Jerusalem and made him God in Rome.”

Constantine left his mark on imperial history both through his military victories and his religious choices. He did not completely eradicate pagan culture; rather, he sought to keep different beliefs united. His legacy can be summed up in two key points:

1–The founding of Istanbul (Constantinople): Relocating the capital of the Roman Empire here altered the course of history. For centuries, the city remained one of the world’s most important centres.

2–The Council of Nicaea: Convened at his invitation, this council marked a turning point in Christian history. The doctrine of the Trinity was formalised; however, it also gave rise to disputes.

At the end of his life, Constantine recalled Arius from exile, thereby drawing closer to the Unitarian Christians. The great Andalusian scholar Ibn Hazm writes in his work Al-Fasl – History of Religions and Sects: “Arius believed that Jesus was only the servant and Messenger of Allah, the Word of Allah and a spirit created by Him. Constantine was the first founder of Constantinople. Among the Roman kings, he was the first to embrace Christianity. He followed the sect of Arius.”

Historian Timothy E. Gregory also states the following in his book Byzantine History: “Constantine could not understand why Arianism spread so rapidly despite being declared a crime in 325. He began to believe that the decision of the Council of Nicaea was wrong and turned to the teachings of Arius. He gathered advisors close to Arianism, such as Eusebius of Nicomedia, and was baptised by Eusebius.”

The renowned historian Alexander A. Vasiliev also notes the following in his voluminous work History of the Byzantine Empire: “In the final years of Constantine’s reign, Arianism had infiltrated the imperial court and was taking root more firmly each year in the eastern part of the empire. Most of those who defended the Nicene Creed were removed from their positions, dismissed from office, and sent into exile. However, the historical data we have regarding the ascendancy of Arianism during this period is not conclusive, due to the unreliability of the sources and the lack of sufficient clarity concerning the circumstances.”

In his book History of the Byzantine State, historian Georg Ostrogorsky similarly states: “In the field of historical science, there are few problems that have been debated as frequently and with such intense effort, and answered in so many different ways, as the issue of Constantine’s relationship with the Christian faith.”

In 337, while on a campaign against the Sassanid invasion, Constantine fell ill en route and died in Nicomedia. In accordance with his will, he was buried in the Church of the Holy Apostles. The debates did not end with his death. The emperors who succeeded him at times supported the Trinitarians and at other times the followers of Arius.

Arius’s views gained widespread support, particularly in Anatolia and North Africa. These communities continued to regard Jesus as the servant and messenger of Allah. This belief closely aligned with Islam’s concept of Tawhid (monotheism). However, church authorities increasingly reinforced the doctrine of the Trinity and declared the views of Arius and those like him to be “heretical.” As a result, the Christian world was shaken by religious divisions for many years. Churches that embraced the Trinity fabricated numerous letters to prove that Constantine did not convert to Arius’s sect in the final years of his life.

Note: Our next article will devote considerable attention to Constantine’s Arian son and his efforts to spread Unitarian thought in Istanbul (Constantinople).