The Christological heresy of Arianism was named for its founder; Arius (c. AD 256–336), a priest of Alexandria. Arius taught that Jesus Christ is the Son of God and was begotten/made before “time” by God the Father, but did not always exist and therefore is not coeternal with God the Father.  Arius held that the Son was distinct from the Father and therefore subordinate to him. Arius stated: “If the Father begat the Son, then he who was begotten had a beginning in existence, and from this it follows there was a time when the Son was not.”

Patriarch Athanasius of Alexandria was the foremost opponent of Arianism who upheld Trinitarian (Homoousian) doctrine and insisted that Jesus (God the Son) was “same in being” or “same in essence” with God the Father.  The controversy over Arianism created political and social upheaval throughout the Roman Empire.  In order to preserve the integrity of the Empire and ensure Church unity, Emperor Constantine convened the ecumenical First Council of Nicaea of 325 A.D.

The Council defined the dogmatic fundamentals of Christianity; that the Father was always a Father, and both Father and Son existed always together, eternally, coequally and consubstantially. The Council declared that the Son was true God, coeternal with the Father and begotten from his same substance.  To describe the divine nature of Christ as being “of one substance with the Father”  the Council employed the Greek term homoousios, or consubstantial (i.e. of the same substance).  The Council argued that such a doctrine best codified the Scriptural presentation of the Son as well as traditional Christian belief about him handed down from the Apostles. This belief was expressed by the bishops in the form of the Nicene Creed, which would form the basis of what has since been known as the Niceno-Constantinopolitan Creed.

Of the roughly 300 bishops in attendance at the Council of Nicaea, only two bishops did not sign the Nicene Creed that condemned Arianism.  Despite this, Arianism persisted for the next few centuries. Emperor Constantine was succeeded by two Arian emperors; his son, Constantius II, and Valens, who both promoted the compromised position of Semi-Arianism and would renew the order for Athanasius’s banishment several times.  Constantius II would send the Arian Bishop Ulfilas as a missionary to convert the Germanic tribes across the Danube to Arianism. Ulfilas’s translation of the Bible into the Gothic language along with his initial success in converting the Goths to Arianism would lead to the widespread diffusion of Arianism by the Gothic, Vandal, and Lombard warlords both before and after the fall of the Western Roman Empire.


  • Papandrea, James L. (2016). The Earliest Christologies: Five Images of Christ in the Postapostolic Age. InterVarsity Press.
  • Ferguson, Everett (2005). Church History. Vol. 1 : From Christ to pre-Reformation. Harper Collins
  • Kelly, J.N.D. (1978). Early Christian Doctrines. San Francisco: HarperCollins.
  • Schaff, Philip. Theological Controversies and the Development of Orthodoxy: The history of the Christian church. volumes III and IX.

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