1700 Years On: The Council of Nicaea and Its Contemporary Importance ~ A guest post by Sebastian Marzanati

The Freelance History Writer is pleased to welcome Sebastian Marzanati, a history student at the University of Nottingham, with a guest post.

Fig 1: Fresco, Narthex of the Great Meteoron (Transfiguration), the Ecumenical Synod of Nicaea I of 325, mid-16th century [photo: D., Sofianos, Meteores: Itineraire (Meteora, 1991), p. 116.]

This article marks the 1700th year anniversary of the opening of the First Council of Nicaea. Traditionally dated from May 20, 325, it was the inauguration of the great Ecumenical Councils of Christianity. Born of Christian Expansion and following doctrinal controversies, Nicaea was convened to standardise the faith for the first time. Presided over by Roman emperor Constantine I (b. 272-d.337), its main outcome was the formation of the Nicene Creed, formalizing the loose rules of the faith that had developed from the late first century onwards concerning God, Jesus, and their natures.

Approximately 250 bishops from across the empire met in Nicaea (now in Istanbul) to resolve doctrinal conflicts like the Arian Controversy, which disagreed on the nature of Jesus. This dispute concerned the relationship of Jesus to God, whether he was homoousios with God (consubstantial, of the same substance/essence), or was created/begotten by Him. The Nicene Creed cemented the synodal creed as a theological and legal document, which would come to define Christian faith until the present day.

However, historical study of Nicaea has more to offer to both Christians and non-Christians, limited by its methodological and narrative challenges. Methodologically, historians must contend with wide-ranging sources and theories when constructing a sufficiently nuanced picture of Nicaea. Narratively, modern theology simultaneously presumes and minimises Nicaea’s legacy.

Post-Enlightenment narratives rejected pre-modern Christianity and its classical influences for Scriptural assumptions about Christian intellectual history and Nicaea’s role in it. These narratives ‘hide the possibility of meaningful dialogue’ between historians and early Christianity. Hence, this article contextualises the First Council of Nicaea, its proceedings, and its legacy, highlighting its importance to us 1700 years on.

The Prelude to Nicaea

Formulation of distinct declaratory creeds emerged in the fourth century with Nicaea, driven by doctrinal conflict. The most significant of these was the Arian Controversy, between the presbyter Arius and his bishop Alexander of Alexandria (modern Egypt). Arius and his followers outlined their faith in a treatise to Alexander in 321, where they rejected orthodox Christology. The orthodox conception of Jesus Christ the Son saw him as not created by God, but of the same substance (consubstantial) and divine, who brought salvation to humanity through his human life and death.

However, the Arian authors highlight the ontological distance between God and the Son, ontology being ‘the nature or essence of being or existence’. The document greatly emphasises the sovereignty and immutability of God, that he alone was ‘unborn’. Hence, Jesus could not be consubstantial with God and was separately created and subordinate to Him. The Arian authors did not reject Christ’s divinity, but considered his status as uniquely granted by God to serve Him freely.

Whilst the document outlines the interrelation and nature of God and Jesus, against orthodoxy, it did not comprise a ‘rule of faith’ let alone a formulaic creed. Alexander of Alexandria defended the orthodox position, expounding that Christ was not born from nothing, ‘but from the Father who exists’. Superficially this appears Arian, but Alexander goes on to describe Christ as a ‘radiance’ or ‘express image’ of God.

This language highlights Christ as eternally begotten by God in his image as opposed to being distinctly created, and thus consubstantial in Him. However, this also did not constitute a formulaic creed but was contained in a treatise written to Alexander of Thessaloniki. Alongside the Arian Controversy, other doctrinal conflicts and jurisdictional issues arose, such as the varied dates of Easter celebrations, (an example is explored in another Freelance History Writer article by Pat Deegan) and the Melitian Schism in Egypt. Thus, the divisive and complex theological developments of the early fourth century drove a synod of bishops to formalise the conceptions and boundaries of orthodox Christianity.

The Council of Nicaea also raises questions about the role of the emperor in managing disputes of the Church, as they posed a political threat in addition to being religiously divisive. By 324 the emperor Constantine I had defeated his opponent Licinius, becoming the sole Roman emperor. His victory was significant, as he had converted to Christianity after winning the battle of Milvian Bridge in 312, and believed that God was responsible for his unification of the empire.

The Arian Controversy, among other disputes, threatened to divide the Church. Thus, Constantine believed that this would anger God, leading Him to withdraw His favour and grace from the chosen people of the Roman empire. This political motivation led Constantine to take the initial approach of mediating between Arius and Alexander of Alexandria.

Fig  2: A coin of Emperor Constantine minted in 327 AD, which highlights the importance of Nicaea and his role due to being the first to use the Christian symbol of the Greek Chi-Rho letters. [Coin of Constantine, British Museum, London: Money and Medals, 1890,0804.11.]

In autumn of 324, Bishop Ossius of Cordoba was sent by Constantine to reconcile the dispute, carrying written orders from the emperor for Arius and Alexander to quietly come to agreement. They did not reconcile, so Ossius hoped to try again during the Council of Antioch in March/April 325, which resulted in a creed. However, as Wolfram Kinzig explains, the sources for this creed are of dubious origin and credibility, invoking caution regarding the creed as a statement directed against Arianism.

What is clear is that the primary agenda of Antioch was the Arian Controversy, with the recorded creed outlining a Christology of the Son as undefinably begotten (but not made) from the Father. This creed is also important for its distinct trinitarian character, dealing with the nature of Father, then the Son, and then Holy Spirit, a formula which was crystallised by the creeds of the fourth century. Antioch also saw the inclusion of anathemas in the creed.

They were a kind of curse, or condemnation, that was pronounced by a bishop or synod. Antioch importantly articulated anathema as a less radical alternative to excommunication, simply condemning the (unnamed) persons who held heretical views like Arianism. Thus, while they were not specifically penalised, Antioch set a precedent for credal pronouncements that contributed to the increasing legal aspects of synodal creeds, such as Nicaea.

The First Council of Nicaea

The question of Constantine’s role arises again with the opening of the Council of Nicaea. He moved the council itself from Ancyra to Nicaea, for its better location for Western travelers, but also so he could personally attend. When the bishops took their places, the emperor himself entered with his entourage, to take his place with the assent of the gathered bishops.

The initial proceedings likely concerned the status of the Arian bishops in attendance, particularly Theodotus of Laodicea, Narcissus of Neronius, and Eusebius of Caesarea (modern Palestine), who had been condemned at Antioch. The varied accounts of Nicaea complicate understanding of the debates, portraying a black box around the actual events obscuring the developments which would result in a creed.

Eusebius sought to prove his faith and did not go against the emperor. He claimed he was the first speaker and asked the emperor to affirm his local Caesarean creed, hence Constantine added the term homoousios, which was included in the final creed. Eustathius of Antioch’s account opposes this, recounting that Eusebius’s creed ‘contained undisguised evidence of… blasphemy’ and was destroyed.

However, Eustathius may have been referring to a different Eusebius (of Nicomedia, not Caesarea), who was rejected for adamantly opposing homoousios. Imperial desire for unity influenced what was presented and agreed to, in addition to the already sharp rhetoric between orthodox and Arian delegates. The reality of what happened in Nicaea is complex, the formation of the creed and the use of homoousios are disputed processes that highlight diverse interpretations of faith.

Nicaea is not just a site for understanding how the foundational creed of Christianity came to be. Its settlement of other doctrinal and jurisdictional issues (noted above) is also important in prompting new understandings. The main tradition of dating Easter was followed by most churches in communion with Rome and Alexandria, but several of the Eastern churches still held to their own tradition. Again, the imperial desire for unity may have shaped the discourse and pronouncement of the Council.

The attending bishops were primarily from the Eastern regions of the empire, with the Syrian and Mesopotamian churches still practicing their Easter tradition in opposition to orthodoxy. Eusebius records that the other delegations were unanimous on the adoption of a single Easter dating system, with the outliers being forced to acquiesce. Constantine’s letters repeatedly emphasise unity to the churches who upheld the results of Nicaea. However, this was not resolved across the empire as Pat Deegan reveals the conflicting Easter traditions of the Anglo-Saxons some 300 years later.

The Melitian Schism threatened the authority of the church in Alexandria, with Melitius of Lycopolis (modern Egypt) rallying Christians who were angry at lenient treatment of those who had not stood up against Rome during the persecutions. They were unusually granted clemency at Nicaea, with clergy simply being allowed to practice again, if under the direction of appropriately orthodox clerics. This reveals the gaps that we still have in our understanding, as no sources record the process of the Nicene delegates arriving at this reconciliation. Indeed, the synodal letter after Nicaea concluded uses a rather condemnatory tone against the perceived weakness of the response to Melitius.

This flared up only years later from 328, with the pro-Nicene Athanasius denouncing and conflicting with the compromise.  Again, as David Gwynn posits, it is likely that Constantine’s desire for unity (and previous experience with the Donatist schism), led to a more charitable outcome that not all may have agreed with. The events and results of Nicaea highlight the complexities of faith and society when navigating internal and external conflicts, desires, and power between ‘those within the Church’ and figures such as the emperor who saw themselves as ‘appointed by God over those outside [the Church]’.

Conclusions

The First Council of Nicaea is central to the formation of Christianity. The Nicene Creed officially laid down core tenets of faith and set the stage for how the average worshipper would practice their faith in everyday life. However, historical understanding of Nicaea has been limited by methods and narratives that ignore the nuance involved in seeing it as a common heritage of present Christians and non-Christians. A common thread in the proceedings before and during Nicaea are themes of unity, diversity, and conflicting interests of power.

Exemplified by the reconciliation of the Melitian Schism, (and subsequent dissatisfaction), or the role of Constantine, such historical moments are driven by broader events and processes and individual desires and actions. These factors need nuance to untangle them, with events today as much as those of Nicaea. The 1700-year anniversary of the First Council of Nicaea may prompt us to seek out a nuanced understanding of history and how it relates to our everyday lives.

Author Biography

I am a final-year history student at the University of Nottingham in England. Throughout my degree I have been interested in medieval & religious history. My extracurricular experiences highlight my belief in the accessibility of the arts and heritage sectors. I likewise want to promote the value and access that everyone should find in history.

Below is my LinkedIn:

www.linkedin.com/in/sebastian-marzanati-ba74311ba

Further Reading:

Ayres, L., Nicaea and Its Legacy: An Approach to Fourth-Century Trinitarian Theology (Oxford, 2004).

Kinzig, W. (ed.), A History of Early Christian Creeds (Berlin, 2024).

Kim, Y. (ed.), The Cambridge Companion to the Council of Nicaea (Cambridge, 2021).

Oxford English Dictionary, ‘Ontology (n.)’: https://doi.org/10.1093/OED/1554916519 (accessed 11/09/2025).

Pomeroy, A. (ed.), A Companion to Ancient Greece and Rome On Screen (Newark, 2017).

Premodernist, ‘What people get wrong about the Council of Nicaea’, 12 June 2025: https://www.youtube.com/watch?v=vNQfUv1nnLM , accessed: 10/08/25.