The Story of the Council of Nicaea

This year marks 1700 years since the first Council of Nicaea was convened. Günther Simmermacher tells the story of how a battle against a heresy gave us the Nicene Creed.

This year, the Church marks the 1700th anniversary of the first Council of Nicaea, which was held from May to July 325 AD in what is now the city of Iznik in the north-east of Turkey.

The Council of Nicaea is relevant even today because the Nicene Creed, which was formulated there, is still recited in Christian liturgies worldwide. Its doctrinal decisions helped shape Christian theology. The council’s emphasis on unity and the orthodox understanding of the Holy Trinity laid the foundation for subsequent theological development in Christianity.

In 325, Christianity had just emerged from being a persecuted faith to a state-supported religion. Emperor Constantine had legalised Christianity with the Edict of Milan in 313, ten years after the long persecution under Emperor Diocletian had reached its climax. Christianity was not yet powerful, and in 325, many adult Christians still remembered the persecutions. Theology and core doctrines were still developing.

Split among Christians

But the Christians were already bitterly divided. One major point of contention was the nature of Christ and his relationship to God the Father. From 318, a sect led by the presbyter (or senior cleric) Arius of Alexandria in Egypt had begun spreading rapidly.

In a nutshell, the Arians denied the full divinity of Jesus Christ, claiming that the Son of God was created by God the Father and therefore was not coeternal nor consubstantial (of the same essence) with him.

This conflicted with the traditional Trinitarian view, which held that Christ was coeternal (already there at the start of creation and not created at a later point by the Father) and consubstantial (of the same essence) with God the Father.

The arguments between the two positions were fierce. In Alexandria, a key centre of learning and theology in the Roman Empire and the Christian world, Arius was in vehement opposition to Pope (or bishop) Alexander I of Alexandria and his young archdeacon Athanasius, who would succeed Alexander as pope of Alexandria within a year of the Council of Nicaea.

The dispute was not only threatening to split the early Church but also to bring political discord into the empire, so Emperor Constantine saw a need to clarify and unify Christian beliefs as a way of bringing order. He asked (or instructed) Pope Sylvester I to convene a council to settle the matter.

318 bishops gather

Thus in May 325, delegates representing all of Christendom gathered in Nicaea for the first ecumenical council of the Christian Church. It was not the first council, nor even the first to be called by Constantine. For example, in 314, the Council of Arles met to condemn the heresy of Donatism and to settle other issues of contention. At Nicaea, the council had to deal with several matters arising from Arles.

The expenses of the council, including the travel of the 318 bishops and their entourages of presbyters, deacons and advisers, were covered by the public purse. The venue was the imperial palace, which today is underwater off the shore of Iznik. The proceedings were chaired by Hosius of Corduba (Córdoba in modern-day Spain), a close advisor to Constantine. The emperor also attended, but in a non-voting capacity — which was just as well, since he was not yet baptised.

The Council began with pomp and ceremony, which would have been unthinkable within a Christian setting just 15 years earlier.

Constantine made his formal entrance to open the council after the bishops had arrived. St Eusebius of Caesarea, the bishop and historian who was never less than a great admirer of the emperor, described Constantine as being “like some heavenly angel of God, his bright mantle shedding light like beams of sunlight, shining with the fiery radiance of a purple robe, and adorned with the dazzling brilliance of gold and precious stones”.

Having duly dazzled Eusebius, the emperor then delivered his opening speech — in Latin, rather than Greek, which was the language of most of the participants.

Presence of saints

Of course, Arius was present, as were St Alexander, with St Athanasius in his entourage as an adviser. Also in attendance were 50 Palestinian leaders, including St Eusebius and St Macarius of Jerusalem. Macarius was on the anti-Arian side, while Eusebius informally supported Arius.

Macarius used the occasion to approach Constantine and humbly request permission to tear down a Roman temple complex that had been built over Golgotha and Jesus’ tomb, suggesting that a small church could be built over the sites of the crucifixion and resurrection.

Constantine agreed and went one better: a couple of years later, he dispatched his mother, Helena, to the Holy Land to finance the construction of several grand churches in places associated with the life of Jesus.

Another delegate was Nicholas of Myra. A story has it that St Nicholas became so infuriated with Arius that at one point he hit him in the face. The mental image of the future “Santa Claus” punching a heretic is certainly intriguing.

Defeating a heresy

Violence or none, the council condemned Arianism and formulated the Nicene Creed as a statement of our faith, adopted on June 19. It defined the nature of Christ as “consubstantial” with the Father and affirmed the belief in the full divinity of Christ. The Holy Trinity was saved from theological mischief!

Arianism was defeated but not destroyed. The split would linger for another 55 years, with the balance of power shifting this way and that, often according to the political climate. As pope of Alexandria for 47 years, poor Athanasius was forced into exile on several occasions.

Constantine himself over time became lenient towards Arians and was baptised on his deathbed in 337 by the Arian bishop Eusebius of Nicomedia, his cousin. His son and successor, Emperor Constantius II (who ruled from 337–361), was an Arian, as was Emperor Valens (364–378), who even persecuted Trinitarian bishops.

Valens’s successor, Theodosius I, ended Arianism through his use of political power and the First Council of Constantinople in 381, which again condemned Arianism, and also reaffirmed and expanded the Nicene Creed. A year earlier, Christianity had become the state religion in the Roman Empire, so Arianism was finally snuffed out, except in some areas outside the empire, particularly in the Germanic regions.

Other matters arising

But back to 325 and the Council of Nicaea, which also had other Church business to address. One of these concerned setting a common date for Easter, which had already been the subject of discussion at Arles.

The use of different calendars now means that the Western and Eastern Churches celebrate Easter on different days. Not by coincidence, Pope Francis this year raised the issue of re-synchronising the date for Easter.

The council promulgated 20 new Church laws, called canons. These included rules governing bishops, clergy, catechumens, and the reception of Communion. Most of them were standard disciplines and administrative matters, though the prohibition on clergy committing self-castration points to a problem very much of its time.

Of interest to Catholics is the prohibition of kneeling on Sundays and during Pentecost. Standing was the standard posture for prayer at this time (as it still is among Eastern Christians). This canon has developed over time.

Much more has changed in the Christian Church in the 1700 years since the Council of Nicaea. There have been schisms and schisms from schisms. The liturgy, disciplines and laws have been adapted and developed.

A time-traveller from the 4th century would not recognise much in the Christian Church today. But our tourist from 325 AD could join us at Mass and — having recovered from all the kneeling — would be delighted to recognise our statement of faith, the Nicene Creed, and the consecration of the bread and wine into the Body and Blood of Christ.

Published in the May 2025 issue of The Southern Cross Magazine