After Nicaea, Arian emperors dominated the church.


This is an article in the series on the origin of the Trinity doctrine. This series shows that the decision to adopt the Trinity doctrine was not taken by the church but by a Roman emperor.

The Roman Empire was a dictatorship and the emperors decided which religions were legal. Furthermore, in the Christian Roman Empire, the emperors were the final judges in doctrinal disputes:

“If we ask the question, what was considered to constitute the ultimate authority in doctrine during the period reviewed in these pages, there can be only one answer. The will of the Emperor was the final authority.” (Hanson, p. 849)

The current article provides an overview of the emperors during the fourth century. It quotes mainly from the recent writings of three world-class Catholic scholars specializing in the fourth-century Arian Controversy, R.P.C. Hanson1The Search for the Christian Doctrine of God – The Arian Controversy 318-381, 1987, Rowan Williams2Arius: Heresy and Tradition, 2002/1987, and Lewis Ayres3Nicaea and its legacy, 2004.



Constantine made sure that the Nicene Council took the kind of decision he thought best but later leaned toward ‘Arianism’.

Council of Nicaea

Constantine ensured that the Council of Nicaea took the kind of decision he thought best. (See here) He called the council, took part in the discussions, personally proposed and insisted on the controversial term homoousios, and exiled the bishops who refused to sign the creed.

Nicaea discussed and soon rejected Arius’ theology. However, by including in the Creed “new terms borrowed from the pagan philosophy of the day” (Hanson, p. 846), the council created a new problem and a new controversy. Constantine took Alexander’s part in his dispute with Arius. At the Council, however, since his view was in the minority, Alexander joined forces with Sabellians. This allowed the Sabellians to include the Sabellian term homoousios. (See Nicaea and Homoousios.)

Objections to Homoousios

Many bishops objected to the term homoousios because it does not appear in the Bible, was borrowed from Pagan philosophy, was not part of the standard Christian language, but had already been condemned at a Synod in Antioch in 268 as associated with Sabellian one-hypostasis (one Person) theology. (See Objections)

Post-Nicaea Correction

In the years immediately after Nicaea, the church successfully eliminated the term homoousios from the church’s vocabulary by exiling the main Sabellian bishops. After that, the term homoousios disappeared from the debate. It was only re-introduced into the Controversy by Athanasius in the 350s; 30 years after Nicaea. (See Correction and Homoousios disappeared.)

Constantine accepted ‘Arianism’.

Soon after Nicaea, while Constantine was still the head of the empire, the tide turned against the Nicenes: 

Arius and the two bishops exiled at Nicaea, soon regained imperial favor, were allowed to return, and were readmitted to communion. Arius was readmitted to communion by the Synod of Jerusalem in 336, under Constantine’s direction but died on the way to Constantinople.

Ten years after Nicaea, in 335, Constantine convened the regional First Synod of Tyre (attended by 310 bishops – more than the number of bishops at Nicaea) to discuss various charges against Athanasius, who now was bishop of Alexandria, including “murder, illegal taxation, sorcery, and treason.” He was convicted and exiled by Constantine. (Read More) Over his long career, Athanasius was exiled no fewer than five times.

Constantine seems to have accepted ‘Arianism’ because he was baptized on his deathbed, it was by the ‘Arian’ bishop Eusebius of Nicomedia.4Gonzalez, Justo (1984). The Story of Christianity Vol.1. Harper Collins. p. 176 This implies that Constantine accepted ‘Arianism’.

Constantine’s deathbed baptism does not mean that he was not a Christian before. It was common for rulers to put off baptism to avoid accountability for things like torture and executing criminals. (The Early Church, 1993, p. 127) On the other hand, Constantine had his wife and son killed in the year after Nicaea.

Divided Empire

Constantine was able to maintain unity in the church but died in 337. His three sons divided the empire between them. This allowed the church to divide East and West:

Constantine II received the far western part.

Constantius received the far eastern part: Macedonia, Greece, Thrace, Asia Minor, Palestine, Syria, and Egypt.

Constans received the area lying in between, namely Italy, North Africa, and Illyricum.

In 340, Constantine II was killed in battle with the forces of Constans. This divided the empire between Constans in the West and Constantius in the East. During this period, the Eastern and Western churches began to oppose one another on the Doctrine of God.


By the year 353, Constantius II became the sole ruler of the Empire and sought to reconcile the divided church by persuading the Western Church to agree to the Eastern creeds which rejected all ousia terms.

In 350, Constans was assassinated by the rebel German emperor Magnentius. Three years later, Constantius defeated and killed the latter. Thus, by 353, Constantius was the sole ruler of the entire empire. 

Constantius inherited a divided church and sought to reconcile it. He attempted to persuade the church in the West to accept the Eastern three-hypostasis theology. In councils held in the West at Arles and Milan, he forced the Western bishops to abandon Athanasius and exiled some of the leaders of the Nicene party. For example, he exiled Pope Liberius and installed Antipope Felix II.

“Although Nicaea spoke against Arianism, Constantine in later life leaned toward it, and his successor, Constantius II, was openly Arian.” (Britannica)

“Under Constantius’ leadership, the Nicene party was largely crushed.” (Encyclopedia Britannica, 1979, Arianism, Vol. I, p.509)

“In 357 a council held in Sirmium forbade the use of ousia (nature or substance) when speaking of the relationship between the Father and the Son. This was a complete victory [for the Arians].” (A Short History of the Early Church, Harry R. Boer, p117)

Some regarded the Third Council of Sirmium in 357 as the high point of Arianism. The Second Creed of that council stated that all ousia (substance) terms, including homoousios (same substance) and homoiousios (similar substance) do not appear in the Bible, “are above … men’s understanding,” and “there ought to be no mention of any of these at all.” It concluded that the Father is greater than the Son. Some Nicene supporters referred to this as the Blasphemy of Sirmium.

Jerome (c. 347–420) is best known for his translation of most of the Bible into Latin (the Vulgate). He remarked that “the term Usia was abolished: the Nicene Faith stood condemned. The whole world groaned, and was astonished to find itself Arian” (The Dialogue Against the Luciferians).

Julian (361-364)

Constantius died 361. His successor was Julian. He was a devotee of Rome’s pagan gods, no longer favored one church faction over another, but allowed all exiled bishops to return. However, he reigned only for three years.

Valens (364-378)

Emperor Valens succeeded Julian, revived Constantius’ policy, and supported the “Homoian” party (the Son is like the Father, without reference to His ‘substance’). Similar to Constantine and Constantius, he exiled Nicene bishops to the other ends of the empire and often used force. This shows again the decisive influence that the emperors had on whether the church was Arian or Nicene.

Theodosius (378-)

Theodosius was the emperor who finally made Trinitarian Christianity the state religion of the Roman Empire and ruthlessly purged the Empire from all other forms of Christianity. (See here)

What Arianism Believed

The article Arianism explains what the church believed during this ‘Arian’ period. It held that the Father is the only God, the Son is our God, but the Father is His God and the Holy Spirit is not a person, but as a power; subject to the Son.

To explain the ‘Arian’ reference to the Son as ‘God.’ The term used in fourth-century Greek was theos. This is often translated as “God” but it is not fully equivalent to the modern term “God.” We use “God” as the proper name of the One who exists without cause. In contrast, the term ‘theos’ was used to refer to any immortal being with supernatural powers, such as the gods of the Greek Pantheon. Read More


During most of the fourth century, ‘Arianism’ dominated because the emperors were ‘Arians’, with the following exceptions:

At first, Constantine took Alexander’s side of the dispute but later leaned toward ‘Arianism’.

Julian was a pagan but ruled only for three years (361-364).

Theodosius was a committed Trinitarian. In 380, immediately after he became emperor, he made Trinitarian Christianity the sole religion of the Empire, outlawed ‘Arianism’ and ruthlessly purged the Empire of it.



  • 1
    The Search for the Christian Doctrine of God – The Arian Controversy 318-381, 1987
  • 2
    Arius: Heresy and Tradition, 2002/1987
  • 3
    Nicaea and its legacy, 2004
  • 4
    Gonzalez, Justo (1984). The Story of Christianity Vol.1. Harper Collins. p. 176

2 Replies to “After Nicaea, Arian emperors dominated the church.”

    1. Not sure how you define ‘Arian’. If that means a follower of Arius, I am not. Arius did not leave behind a school of disciples. Athanasius coined the term ‘Arian’ to insult his opponents. See here. Hanson defines ‘Arian’ as a person who believes the Son is subordinate to the Father. That would be me. But I would say simply I oppose the Trinity doctrine in which the Father, Son, and Spirit are one Being with one mind. (See here) I do believe that Jesus is the Yahweh of the Old Testament, but I still believe that the Father, the only One who exists without cause, is a distinct Being with a distinct mind, infinitely above His Son, just like the Son is infinitely above His creation. That, I think, is what the church believed during the first centuries.

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