Was the date for Christmas decided at the Council of Nicaea (AD 325)?

Daniel Woon


Constantine the Great convened the first Council of Nicea to decide upon the official date for Christmas: the 25th of December.




Constantine was the first emperor to put an end to the persecution of Christians. The Edict of Milan, which he developed alongside Licinius in February 313, legalised Christianity, removed any penalties for religious practices and returned confiscated Church property.

These reforms were also unexclusive to Christianity meaning that all religions and cults throughout the Roman Empire were protected from persecution under the Edict, allowing people to follow their faith without oppression.

Why was the Council of Nicaea called?

Between the years AD 320 and 324 there had been a growing divide amongst the various Christian communities due to the controversy emanating from the Arius doctrine which disputed the divine nature of “the Son”. Conflicts continued to rise in the church at Antioch following the death of Bishop Philogonius and, in an attempt to extinguish their differences, a synod was assembled by Ossius, the bishop of Corduba. The Synod of Antioch, which 59 bishops had attended, resulted in the suspension of those that supported Arius.

Another synod was called for by Ossius with the aim to clarify the key canons of Christian faith. Originally, this synod was supposed to have been held in Ancyra until it was moved by Constantine to Nicea in 325. Additionally, 49 out of the 59 bishops that attended the Synod of Antioch also attended the Council of Nicea, which would indicate that the initial idea of the Nicene Council should be accredited to Ossius rather that Constantine; and was assembled with the primary purpose of settling the Arius controversy.

Constantine’s efforts and support for Christianity during his reign provided him with great influence and authority within the early Christian councils. Constantine ultimately convened the first Council of Nicea on June 13 in AD 325, which adopted the Nicene Creed. The opinions of Arius, that led to his condemnation, stemmed from the beliefs surrounding Jesus’ birth and death. Indeed his passover, along with the date for the celebration of Easter was discussed at the Council of Nicea. According to Christain laywer and histrorian Sozomen (1.21):

The Council decided that the Paschal feast was to be celebrated at the same time in every place.

Taking into account this consideration of Easter, it would be understandable to assume that the date for Christmas was also part of the agenda, due in no small part to the fact that both the resurrection of Jesus and his birth were explicitly mentioned in the Nicene Creed (passages from the Nicene Creed in a modern English translation from the original Greek):

He came down from heaven, and by the Holy Spirit was incarnate of the Virgin Mary and became man. For our sake he was crucified under Pontius Pilate, he suffered death and was buried, and rose again on the third day in accordance with the Scriptures. He ascended into heaven…

However, there appears to be no evidence that supports the claim that the date for Christmas was decided or even mentioned at the council. It seems to be entirely speculation.

Perhaps the reason for this claim stems from an inaccurate belief that the Council was called to establish an accepted timetable for the Christian festivals. In reality, the Creed was adopted because of ongoing religious disputes and the Arian Controversy, in particular, threatened social stability in large portions of the Roman Empire. For this reason, the Council sought to establish a solid orthodoxy within the Empire.

The focus was on much deeper theological disagreement than the simple date of Christ’s birth. The result of the ecumenical Creed, which combined both the Council of Nicea (325) and the Council of Constantinople (381), explicitly announced faith in the Father, the Son and the Holy Spirit and recognised them as consubstantial (Eusebius, Life of Constantine 2.71):

As far, then, as regards the Divine Providence, let there be one faith, and one understanding among you, one united judgment in reference to God. But as to your subtle disputations on questions of little or no significance, though you may be unable to harmonize in sentiment, such differences should be consigned to the secret custody of your own minds and thoughts.

So why do we celebrate Christmas on the 25th?

Today, many of us celebrate Christmas on the 25th of December as it is believed to be Jesus Christ’s birthday. Indeed, there has been a vast amount of research as to when his actual birthday was. However, for the purpose of this article I will focus on its origin.

The earliest recorded date for an annual feast day commemorating Jesus’ birth on the 25th of December can be found in the Chronography of 354, which noted the earliest known Christmas celebration in AD 336:

Part 12: commemoration dates of the martyrs Line 1: “VIII kal. Ian. natus Christus in Betleem Iudeae” – “Eighth day before the kalends of January [December 25] Birth of Christ in Bethlehem of Judea”

This evidence for the date of December 25th as Jesus’ Birthday coincides with an earlier source from AD 221. Sextus Julius Africanus – the first Christian historian – wrote a five-volume treatise called the Chronographiai. Modern historians such as Nothaft (2013, p.264) claim that Sextus calculated Jesus’ conception to be March 25. This date of conception would result in a birth on December 25 if he were born exactly nine months later.

Herman Usener (1969), a German philologist who pioneered modern scholarship on religion, projected that the affirmation of the birth of Christ being on the 25th December had developed out of pagan festivals like saturnalia and the celebration of Sol Invictus – however, this view has been a subject for debate and historians, such as Hijman (2011, p.150), argue that the ancient festival of Sol was rediscovered in a response to Christianity’s appropriation of December 25th.

Other scholars have also suggested that the reason for this date was a political strategy to undermine pagan practices throughout the Roman Empire. The incorporation of pagan practices can be detected in late antique Christian sources that describe Jesus as the “true Sun” referring to the birth of the “sun” on the 25th which applies to both Sol Invictus and Jesus Christ. The view that Christmas was introduced as a reaction to pre-existing pagan practices has been a futile point of view; instead historians such as Martin Wallraff (2001, p.194) argue that they were “parallel phenomena”.


This article has reviewed the designation of Christmas day to the 25th of December, looking at surrounding factors that could have played a part in affirming the 25th as Christmas day. The fact is, there is no evidence to support the claim that the date for Christmas was decided at the council of Nicea in AD 325, nor is there any evidence at all that shows us when the date for Christmas was universally adopted by the various Christian sects. All we have to go by are the words of one Roman Christian historian and a date for the earliest known Christmas celebration in AD 336.

For these reasons, we have rated this claim false.

Related claims


  • R.W. Burges, “The Chronograph of 354: its manuscripts, contents, and history”, Journal of Late Antiquity, 5 (2012), pp. 345-96.
  • S. Fernández, “Who convened the First Council of Nicaea: Constantine or Ossius?”, The Journal of Theological Studies 71.1 (2020), pp. 196-211.
  • S. Hijmans, “Usener’s Christmas: a contribution to the modern construct of Late Antique solar syncretism”, in: Michel Espagne and Pascale Rabault-Feuerhahn (eds), Hermann Usener und die Metamorphosen der Philologie (2011), pp. 139-152.
  • C.P.E. Nothaft, Early Christian Chronology and the Origins of the Christmas Date: In Defense of the “Calculation Theory”(2013).
  • C.P.E. Nothaft, “The origins of the Christmas date: some recent trends in historical research”, Church History 81.4 (2012), pp. 903-911.
  • F. Parente, “Das Weihnachtsfest”, in: G. Arrighet-ti et al. (eds), Aspetti di Hermann Usener, filologo della religione (1982), pp.181-211.
  • T.E. Pollard, “The Creeds of AD 325 Antioch, Caesarea, Nicaea”, Scottish Journal of Theology 13.3 (2009), pp. 278-300.
  • T.C. Schmidt, “Calculating December 25 as the birth of Jesus in Hippolytus’ Canon and Chronicon”, Vigiliae Christianae 69.5 (2015), pp. 542-563.
  • N. Tanner, “Greek metaphysics and the language of the Early Church Councils: Nicea I (325) to Nicea II (787)”, Gregorianum 90.1 (2009), pp. 52-57.
  • H. Usener, Das Weihnachtsfest (3rd edition, 1969).
  • M. Wallraff, Christus verus sol (2001).