First Ecumenical Council of Nicaea, 325

1. The Council’s historical context

Since 312 Constantine I the Great (306-337) took action that underlined his determination to intervene in ecclesiastical matters. From 316 onwards, he began appearing as the supreme arbiter in the disputes among the bishops. The involvement of the emperor in the so-called Donatist schism,1 which convulsed Roman Africa throughout the 4th century, marked a failure of his religious policy.

During the persecutions conducted by Diocletian (284-305), several clerics had renounced their faith, hurling their sacred texts into the fire.2 A growing number of other Christians, however, wishing to express their disagreement and zealously exhibit their unswerving faith, sought a martyr’s death. Among them were the followers of Donatus Magnus. When in 313 Caecilian was ordinated archbishop of Carthage, the Donatists, accusing him for his submissiveness during the persecutions, rebelled and appointed Donatus as archbishop. This appointment caused reactions and soon took on the proportions of a schism spreading throughout Africa. The emperor attempted to restore the Church’s unity; but, after four years of persecutions, he started showing tolerance towards the schismatics, for his main concern was to bring peace within the Church and unity among the religious functionaries.

Of all the religious issues Constantine had faced in the East, the most pressing was the feud between Alexander, bishop of Alexandria, with the presbyter Arius. Arius’ teachings remained very popular up to the 7th century, their appeal reaching beyond the confines of the Roman Empire. Arius disputed Jesus’ divinity, regarding him as a creature of God. In many local councils this teaching and its adherents had been condemned and anathematized; however, its influence rose steadily. In November 324, Constantine dispatched a trusted attendant of his, Hosius, bishop of Corduba in Spain, bearing an imperial letter addressed to both Alexander and Arius. Hosius’ mission was to examine in depth the situation in the East and attempt to bring about a compromise between the two clerics. According to the emperor’s view, the two men were arguing “over small and rather unimportant issues”.3 This letter survives in the works of Eusebios of Caesarea and indicates Constantine’s nonchalance towards dogmatic matters. Hosius was unsuccessful in his mission, returning, however, to the emperor fully convinced of the correctness of Alexander’s position. Thus in February of 325, Arius was condemned once more, this time in Antioch, in yet another local council. Later in that same year, Arius tried to meet Constantine in Nicomedia to convince him of the soundness of his teachings. The emperor, however, due to his earlier painful experience from the Donatist schism in North Africa, decided to forgo diplomacy and half-measures and convened the First Council of the Church in Nicaea of Bithynia. This Council was not convoked as ‘ecumenical’. This term is later, its import being theological and mainly dogmatic. A council is described as ‘ecumenical’ by a later council which accepts the pronouncements of the earlier one as a dogmatic decree, mainly to prove that it acknowledges the earlier council’s authority. Thus during the Council of 381 in Constantinople, the Council of 325 in Nicaea was termed «First Ecumenical Council». Other councils had taken place in the meantime (Ankyra, Serdike, Antioch etc). The term «ecumenical» in the case of councils and in general in the Eastern Orthodox Church does not denote geographical or other measurable dimensions, but refers to the dogma and its power in the Christian ecumene, i.e. the Church. Thus, Sozomen first among the historians talks of the first «Council of the Ecumene»,4 from which only the Donatists were excluded. Eusebiοs writes that the place of the council was chosen by Constantine himself, due to the auspicious name the city bore (Nicaea=victorious).5

2. The Council and Emperor Constantine

According to Eusebiοs, 250 bishops and countless presbyters, deacons and acolytes flocked to Nicaea towards the end of spring of 325 from every corner of Christendom: «the Council was also attended by a Persian bishop, and no Scythian was found wanting in the chants».6 The clerics used public vehicles7 to travel to their destination, and this was one of the many privileges Constantine granted to the clergy.

The proceedings of the Council began with every formality on May of 3258 in the palace of Nicaea. Although the emperor was not baptized, and was still a catechumen, he proclaimed the opening of the Council and presided over its meetings. The commencement was organized in such a way as to promote the imperial office and underscore the status of the ruler as pontifex maximus of the Roman state. When all the attendees were present a signal was given, the gates opened and Constantine appeared «like a messenger of God, gleaming like sunlight in his attire, illuminated by the fiery rays of his purple robe, graced by the light reflected on the gold and precious stones of his jewellery».9 In this way Constantine gave a definitive form to the hieratic image of the emperor, which was to remain so for the entire Byzantine era,10 underlining the caesaropapism of the state system during the Middle Ages in the East. While impressing on the bishops the idea of the majesty of the imperial office, Constantine also sought to exhibit to the attendees his Christian humility as well, which he considered a necessary characteristic of rulership. Thus he refused to take the seat he was offered, waiting patiently for all the priests to take their places, and during the meetings he constantly strove to create an atmosphere of cordiality, expressing his opinion on every subject in broken Greek, according to Eusebios' testimony.11

Constantine immediately ordered the burning of all the libellous memoranda the bishops had submitted to him, without even reading them. In his inaugural speech, given in Latin, he stressed the importance of peace and concord. He was not interested in the particulars of the solution that would eventually be given to the theological problems, and his aim was fully achieved. The Council finally compiled the first seven articles of the Creed,12 in which the Son was defined as «consubstantial» (homoousios) with the Father, this being the critical definition; they also compiled 20 canons determining issues of religious priority and behaviour. The computation of the day for the celebration of Easter was also ordered. There was also an almost unanimous decision to banish Arius to Egypt13 – his supporters, Eusebios of Nicomedia and Theognis of Nicaea followed him into exile and humiliation. It is almost impossible to have a precise picture on the way the meetings were conducted, for no account of the council's proceedings have survived.14 It is certain, however, that Constantine played an energetic and decisive role in the whole process, initiating a tradition of interventionism by the secular power into ecclesiastic affairs. Far from being a movement viewed with negativity, Christianity was now officially accepted and evolved into one of the pillars of the empire. Its highest representatives, together with the imperial officials would from now on form the ruling class. On the other hand, in the summer of 325, the twenty years Constantine’s rule were celebrated in all splendour according to the Christian ritual. During these festivities, a formal speech was given by Eusebios of Caesarea, a figure illustrating the triumphal entrance of the Church and the intellectuals in the environment of the imperial court, as well as the politicization of the Christian teaching.

3. The theological issues of the Council

3.1. The Ekthesis (Exposition) of Nicaea

The following ecclesiastical cycles were represented in Nicaea:15 a) the Arians and their sympathizers,16 b) Eusebios, bishop of Caesarea and Palestine, historian of the Church, a temperate Arian himself and supporter of conciliatory solutions, c) the circles of Nicaea that finally compiled the famous Ekthesis (Exposition), which dominated later theology.

According to sources contemporaneous to the Council, the number of bishops who signed the Ekthesis ranges from 250 and 300. A tradition dating to the late 4th century finally established a number of 318 bishops; this number (τ'ιη' in Greek) is apparently fictitious, with a symbolic meaning. It is a symbol of the Crucifixion, because visually Τ reminds an ancient crucifix and the letters ιη are an abbreviation of Jesus’ name in Greek (Ιησούς). At any rate, the Ekthesis of Nicaea is the first attempt of the Christian Church to codify its teachings in a dogmatic definition, and it is also an important milestone in the history of the relations between the State and the Church.

The first formulation of the Ekthesis' clauses was modified and named «Creed» in 451, by the 4th Ecumenical Council of Chalcedon. Only bishops had the right to vote in the councils. In the ecclesiastical affairs the will of the emperor was always dominant, and this can be seen in the fact that Constantine imposed the addition of the epithet «consubstantial» without any of the bishops present daring to express any objection. The Spanish bishop Hosius was the inspirator of the epithet «consubstantial», and of the emphasis on the notion of the «essence», to the text. This is interpreted as an influence by Western theology with its interest in more elaborate definitions, as many of the hierarchs of the East were unable to perceive the importance and the ontological dimensions of this term. However, another group, among which was Athanasios the Great, accepted and zealously supported the modified Ekthesis which contained the term «consubstantial».

Following the compilation of the Ekthesis, the bishops that refused to sign it were condemned to exile together with Arius, and the writings of his adherents were thrown into the fire.

3.2. Establishment of a date for the celebration of the Easter feast

In 325 there was confusion concerning the date on which Easter was to be celebrated, a confusion that reached far back into the past.17 Some wanted to celebrate Easter always on Sundays, while others followed the Jewish tradition. The Jewish Easter18 was an immovable feast, celebrated on the 14th day of the Nisan month, a day which always coincided with the full moon.19 For this reason the Nisan month always began with the new moon closest to the vernal equinox, which could not always occur on a Sunday, something unacceptable for the Christians celebrating the Resurrection. Over time more disagreements were added to these. Constantine the Great and the Council of Nicaea ordered the celebration of the Easter on the first Sunday following the full moon which coincides or follows the vernal equinox, but Christian Easter should not coincide with the Jewish feast and should be celebrated on the same day throughout the Christian world.20

4. Athanasios the Great against Arianism

An important role in solving the theological and dogmatic issues was played by Athanasios the Great, who participated in the Council of Nicaea as a deacon of the Alexandrian patriarch, Alexander, and due to his capacity could not be elected as a member of the Council.21 After Alexander’s death (328) Athanasios was elected bishop (patriarch) of Alexandria, retaining this office until his death (373). Athanasios' writings are an important source for the teachings of Arianism. From the works of the bishop of Alexandria we know that together with Arius travelled to Nicaea some of his most eminent followers, like the sophist Asterios, Eusebios of Nicomedia, Eudoxios, Aetios and the bishop of Cyzicus Eunomios.

The basic tenets of Arius’ teaching are stigmatized and anathematized in the end of the Ekthesis of 325.22 According to this teaching, God is «sempiternal», «without beginning» and «unbegotten», while Christ is «begotten», a «creature», «something created» or, in other words, the Son is a being made by the Father. Thus Christ appears inferior to God, who was not always the «Father», having acquired this attribute only after He willed the world into existence. It is at this point that the impersonal and primordial powers, Wisdom and Logos, received form to function as instruments in the creation of the world. That is to say that Wisdom and Logos were personified under the name of the Son. Thus, the creation of the world coincides with the creation of Christ (the Son-Logos). Until then Christ remained insubstantial. The idea that Christ is a creation of God led to the view that the Son is dissimilar to the Father in terms of his essence, less perfect, by nature «mutable», «alterable», and for this similar to human beings, which can fall into sin. However, being the first-born of all creatures of the Perfect Creator, Christ was accorded perfection and is nominally worthy of being worshiped as a true God.

The most important argument of the Fathers of the Council of Nicaea against the adherents of Arianism was that, insofar as the Arians accepted the worship of Christ as a creature, they were no different from the pagans. Athanasios argued that Arius misinterpreted the passages of the Sacred Scripture23 on which he based his teachings. According to Athanasios, God had the power of creation and did not require some instrument to build the world through it; at any rate, Christ could not supplement the work of the Creator.24 Basing his arguments on the Scripture,25 Athanasios proved the consubstantiality of God. He also proved the unity of the essence of God and Son and subsequently the consubstantiality of the Son. Thus the Son is similar to the Father and eternal, for he proceeded from Him, like the Sun remains indivisible as a primordial source of light. Christ simply received mortal form in order to deliver the human kind from sin.26The incarnation of the Son was interpreted by Athanasios by reference to the need to redeem the sinful humanity, contrary to what the Arians held, i.e. that Christ was crucified to become God. The young deacon argued that Jesus sometimes unconsciously forgot his divine nature and acted as human; this was not because, however, he did not know His Father, as the Arians claimed.27 Arius argued that a rational human soul was never a part of Christ’s human nature. This view has its roots in the teaching of Origen, which was considered valid on dogmatic issues, and as such was accepted by Athanasios.

The dispute between Arius and Athanasios in Nicaea of Bithynia indicated that their Christological views shared a common origin, i.e. the Alexandrian tradition of Origen’s school. In a way Arius was also influenced by the ideas of Paul of Samosata and Lucian of Antioch. The diverging views of these two clerics were rather the result of their deviating literal interpretations of specific scriptural passages, notwithstanding the common source of their philosophical argumentation.

5. The ecclesiastical regulations of the First Ecumenical Council

The Roman Empire had 4 praefecturae (prefectures).28 Rome and Constantinople were separately governed by a praefectus urbis. The Eastern Church adopted this organizational model. In the early 3rd century, out of the 4 prefectures evolved 3 new ones, i.e. Rome, Alexandria and Antioch. In the 4th century the seat of Constantinople was also formed, as a unit with enhanced administrative functions. The metropolitans of these four seats from the 5th century onwards were called Patriarchs. The bishop of Jerusalem maintained his honorary office (in accordance with the 7th canon of the 1st Council of Nicaea), due to the city’s religious and not administrative importance.29

In the 20 canons formulated during the First Ecumenical Council, important regulations pertaining to the Church organization were ratified: the dioceses, the hierarchical order among archbishops and bishops etc.

Among these, of particular significance was the 6th canon, which confirmed the special privileges and the preeminent position of the bishop of Rome,30as well as that of the metropolitans of Alexandria, Antioch and Jerusalem. The archbishop of Alexandria occasioned the compilation of the 6th canon, for his rights were threatened by Meletius of Lycopolis. This seat was the most powerful during the 4th century and the attendees at Nicaea felt the need to sign some sort of an agreement that would declare the equality of the seats of the Ecumenical Church. The 6th canon, though, delineated the future framework for the dwindling of the influence of the Antioch and Jerusalem seats vis-à-vis the prevailing of Rome and Constantinople. Following Cyril’s death (444), Alexandria also began to fall behind in importance.

6. Consequences

To restore peace in the Church, Constantine the Great appeared rather conciliatory towards Arius’ followers. Thus, after 325 the Orthodox views of the First Ecumenical Council began to loose ground. There were even some moves to return Arius in the bosom of the Church. He was forced to compile a new Creed, which did not contain any heretical views, but which also did not include the term «consubstantial».31 The sons and heirs of Constantine, Constantine II (337-361) and Constans (337-350), who ruled the western part of the empire, supported the decisions of the Council, but their brother Constantius II (337-361), emperor of the East, inclined towards Arianism. A series of regional councils after 325,in Ariminum, Sirmium, Antioch, Serdike, Seleucia and Nicaea of Thrace resulted in a variety of Arianizing creeds, which distanced Orthodoxy from the basic principles of the Ekthesis.32

The pagan emperor Julian (361-363) attempted to fully overturn the Christian dogma. Subsequently, the rulers Jobian (363-364) and Valentian I (364-375) showed respect to the decisions of the Nicaea Council, but the latter’s brother, Valens (364-378), continued Constantine II’s Arianizing policy.

In the field of theology, Athanasios of Alexandria continued his fight against the Arians with his virulent writings,33creating many enemies. His work was continued by three Cappadocian theologians: Basil the Great (329-379), Gregory of Nazianzos (c.330-390) and Gregory of Nyssa (ca. 335-394). These theologians fought against the Arians, but without the histrionics of Athanasios, managing, though, to philosophically establish the Trinitarian dogma of Nicaea.

7. Sources

Our main source on the First Ecumenical Council is the Ecclesiastical History34 of Eusebios of Caesarea (c.260-339). The History of the First Ecumenical Council by Gelasius of Cyzicus,35dating to the last quarter of the 5th century, mainly contains folklore and legends that subsequently shrouded the event. The works of Athanasios of Alexandria,36 as well as the Ecclesiastical History of Socrates,37 of Sozomen38, of Theodoret of Cyrrhus and of Rufinus39 preserve enough details to allow the reconstruction of the dogmatic debates of 325. The treatises against the Arians by Basil the Great, Gregory Nazianzus, Gregory of Nyssa and others can also be considered as indirect sources for the theological views expressed in Nicaea.




1. This is the quarrel between Caecilian and Donatus over the bishopric of Carthage

2. Ιστορία του Ελληνικού Έθνους Ζ΄ (Αθήνα 1980), σελ. 36.

3. Eusebius, Vita Constantini, book 2, 71, 1.

4. Sozomen I, 20. 1.

5. Eusebius, Vita Constantini, book 2, 71, 2.

6. Eusebius, Vita Constantini, book 3, 7, 1.

7. Up to then public vehicles were only used by state functionaries on missions regarding the state. The Emperor covered all the subsistence expenses for the bishops and their entourages for the duration of the Council; this caused many complaints and Constantine was criticized by his successors for this move. See Χριστοφιλοπούλου, Αι., Βυζαντινή ιστορία Α΄ (Θεσσαλονίκη 1992), p. 137.

8. Some historians argue that the proceedings of the Council began in mid-July of 325. See Cristianstvo – enciklopediceskii slovar II (Moskva 1995), p. 201.

9. Eusebius, Vita Constantini, book 3, 10, 3-4.

10. Ιστορία του Ελληνικού Έθνους Ζ΄ (Αθήνα 1980), p. 37.

11. Eusebius, Vita Constantini, book 3, 10, 8-10.

12. The name is later.

13. Only two bishops voted against this. See Χριστοφιλοπούλου, Αι., Βυζαντινή ιστορία Α΄ (Θεσσαλονίκη 1992), p. 137.

14. Revillont’s edition of the Coptic minutes of the First Council is considered a forgery by modern scholars. For the minutes of the Ecumenical Councils see Mansi, J.D., Sacrorum conciliorum, nova et amplissima I (Florentiae 1759, reprinted 1960-1961); Schwartz, E., Acta conciliorum oecumenicorum (ACO), vols. I-IV 2 (Berolini et Lipsiae 1913-1940) and elsewhere.

15. See Θρησκευτική και ηθική εγκυκλοπαιδεία ΙΑ΄ (Αθήναι 1967), pp. 525-530.

16. According to Theodoret, the Arian bishops were 10; Rufinus mentions 17, while Philostorgius talks of 22 persons.

17. Lebedev, A.P., Vselenskie sobori 4 i 5 vv. (Moskva 1881), pp. 14-28.

18. The celebration of the crossing of the Red Sea by the Israelites during their exodus from Egypt.

19. The Jewish months are lunar, and begin with the new moon.

20. This issue proved contentious, for based on astronomical data the date of Easter was calculated differently in Alexandria and Rome. In 525, however, Dionysius Exiguus prepared Easter tables which were accepted by the Church. This conformity ceased in 1582 with the reformation of the calendar by Pope Gregory XIII.

21. Athanasios´ Vita in Acta Sanctorum, Mai I (1680), pp. 186-258.

22. On Arianism in general see Newman, J.H., The Arians of the Fourth Century (London 1881).

23. These are the passages in: Deuteronomy 6, 4, Proverbs 8, 22-5, Gospel according to John 14, 28, Gospel according to Mathew 27, 26 and elsewhere.

24. Cross, F.L., The Study of St. Athanasius (Cambridge 1945).

25. Gospel according to John 10, 30, Epistle to the Hebrews 1, 3, Psalms 2, 7, Acts 13, 33 and elsewhere.

26. On the incarnation of Christ see Ryan, G.J. – Casey, R.P., De Incarnatione (1945-1946); Bouyer, L., “L’Incarnation et l’Eglise-Corps du Christ dans la Theologie de S. Athanase”, Studia Patristica 3 (1982), pp. 981-1045 and elsewhere.

27. These claims of the Arians are based on the Sacred Scripture, Gospel according to John 11, 34.

28. Lübek, K., Reichseinteilung und kirchliche Hierarchie des Ostens bis zum Ausgange des vierten Jahrhunderts. Ein Beitrag zur Rechts- und Verfassungsgeschichte der Kirche (Kirchengeschichtliche Studien V, Heft 4, Münster 1901).

29. Cf. Posnov, M., Istorija na hristianskata carkva 2 (Sofia 1993), pp. 89ff.

30. The affirmation of the Pope’s role by the First Ecumenical Council was based on: a) Rome’s preeminent position as the capital of the empire, b) the fact that the city contained the relics of the apostles Peter and Paul, and c) to the theory of apostle Peter’s dogmatic priority, which was passed on to the Pope.

31. Ιστορία του Ελληνικού Έθνους Ζ΄ (Αθήνα 1980), σελ. 400.

32. On the theological currents of this period see Kelly, J.N.D., Early Christian Doctrines (1960), passim.

33. The works of Athanasius the Great have been translated into English by Bright, W., Orations against the Arians (Oxford 1873, reprinted in 1883) and in Historical Writings of Athanasius (Oxford 1881).

34. The Loeb Classical Library I-II (London 1959-1964).

35. Gelasii Cyzicensia Historia concilii Nicaeni, PG, LXXXV, col. 1192-1134.

36. The main sources are the three orations of Athanasios “Against the Arians” and two epistles, one written in 350-351, concerning the decisions of the Council of Nicaea, and the other one «On the Events of the Councils in Ariminum and Seleucia».

37. Migne, J.P., PG, vol. 67, 29-842.

38.  Migne, J.P., PG, vol. 67, 843-1630.

39. Rufini Historia ecclesiastica, Pl, XXI, col. 461-540.