Arianism - Theodosius and The Council of Constantinople

Theodosius and The Council of Constantinople

It was not until the co-reigns of Gratian and Theodosius that Arianism was effectively wiped out among the ruling class and elite of the Eastern Empire. Theodosius' wife St Flacilla was instrumental in his campaign to end Arianism. Valens died in the Battle of Adrianople in 378 and was succeeded by Theodosius I, who adhered to the Nicene creed. This allowed for settling the dispute.

Two days after Theodosius arrived in Constantinople, 24 November 380, he expelled the Homoiousian bishop, Demophilus of Constantinople, and surrendered the churches of that city to Gregory Nazianzus, the leader of the rather small Nicene community there, an act which provoked rioting. Theodosius had just been baptized, by bishop Acholius of Thessalonica, during a severe illness, as was common in the early Christian world. In February he and Gratian had published an edict that all their subjects should profess the faith of the bishops of Rome and Alexandria (i.e., the Nicene faith), or be handed over for punishment for not doing so.

Although much of the church hierarchy in the East had opposed the Nicene creed in the decades leading up to Theodosius' accession, he managed to achieve unity on the basis of the Nicene creed. In 381, at the Second Ecumenical Council in Constantinople, a group of mainly Eastern bishops assembled and accepted the Nicene Creed of 381, which was supplemented in regard to the Holy Spirit, as well as some other changes: see Comparison between Creed of 325 and Creed of 381. This is generally considered the end of the dispute about the Trinity and the end of Arianism among the Roman, non-Germanic peoples.