The Arian heresy (4) the 56 year between the council of nicaea 325to the Council of Constantinople (381)

The 56-year period between the Council of Nicaea (325) and the Council of Constantinople (381) was marked by an intense struggle as the Nicene definition of Christ’s deity faced repeated challenges from Arianism and various "subordinationist" views.

The following timeline details the major events of this era involving Arius, Athanasius, and the shifting theological landscape of the Roman Empire:

The Post-Nicaea Transition (325–337)

• 325: The Council of Nicaea. This first ecumenical council condemned Arius and adopted the term homoousios ("of the same essence") to affirm that the Son is fully God. Arius was excommunicated and exiled by Emperor Constantine.
• 328: Athanasius becomes Bishop. Following the death of Alexander, Athanasius was elected Bishop of Alexandria, becoming the primary champion of Nicene theology for the next 45 years.
• 328: Arian Resurgence. Eusebius of Nicomedia, a powerful Arian sympathiser, gained the ear of Constantine and persuaded him to recall Arius from exile.
• 335: First Exile of Athanasius. Arianising bishops convened the Council of Tyre, which deposed Athanasius on political charges. Constantine banished him to Trier in Gaul.
• 336: The Death of Arius. Shortly before he was to be reinstated to communion, Arius died suddenly in Constantinople.
• 337: Death of Constantine. The empire was divided among his sons; Constantius II ruled the East and favoured Arianism.

The Era of Division and Imperial Pressure (339–360)

• 339: Second Exile of Athanasius. Constantius II banished Athanasius again, forcing him to flee to Rome.
• 341: Council of Antioch (Dedication Council). Eastern bishops drew up new creeds that omitted the word homoousios, fearing it sounded too much like Sabellianism. (a Christian heresy asserting that God is one single person (a "monad") who appears in three different "modes" or roles—Father (Creator), Son (Redeemer), and Holy Spirit (Sanctifier)—rather than three distinct co-equal persons 
• 343: Council of Sardica. Intended to reunite the church, it resulted in a total split; Western bishops reaffirmed Nicaea, while Eastern bishops condemned Athanasius.
• 346: Athanasius Returns. Following a temporary shift in imperial politics, Athanasius returned to Alexandria.
• 353: Constantius II as Sole Ruler. Constantius used his sole power to systematically persecute Nicene believers and enforce Arianism.
• 356: Third Exile of Athanasius. Imperial troops attempted to arrest Athanasius in an Alexandrian church; he escaped and lived in hiding among desert monks for six years.
• 357: The "Blasphemy of Sirmium". A council at Sirmium issued a creed that explicitly forbade the use of both homoousios and homoiousios ("of a similar essence").
• 359: The "Groaning" World. Joint councils at Ariminum and Seleucia were pressured into accepting a vague "Homoean" creed stating the Son is simply "like" the Father.

The Nicene Recovery (361–381)

• 361: Julian the Apostate. Emperor Julian recalled all exiled bishops, including Athanasius, hoping to foster Christian infighting to weaken the faith.
• 362: Synod of Alexandria. Athanasius convened a council that sought to reconcile those who used homoousios with those who used homoiousios, recognising they shared the same intent.
• 364–378: The Reign of Valens. In the East, Emperor Valens renewed Arian persecution. Athanasius suffered his fifth and final exile (365–366) before his death in 373.
• 370s: The Cappadocian Fathers. Basil of Caesarea, Gregory of Nazianzus, and Gregory of Nyssa refined the theological language of the Trinity, distinguishing between one ousia (essence/nature) and three hypostases (persons).
• 380: Edict of Thessalonica. Emperor Theodosius I made Nicene Christianity the official religion of the Roman Empire, legally outlawing Arianism.
• 381: Council of Constantinople. This Second Ecumenical Council reaffirmed the Creed of Nicaea and explicitly affirmed the deity of the Holy Spirit.

Endnotes

1. Needham, Nick. 2,000 Years of Christ's Power, Vol. 1: The Age of the Early Church Fathers. Grace Publications.
2. Shelley, Bruce. Church History in Plain Language, 4th Edition. Thomas Nelson.
3. Ferguson, Everett. Church History, Volume 1: From Christ to Pre-Reformation. Zondervan.