Council of Nicaea — Defining Christian Orthodoxy
The Arian controversy threatened to split Christianity — and therefore the empire — in two. The Alexandrian priest Arius taught that the Son was created by and therefore subordinate to the Father ('there was a time when He was not'). His opponent Athanasius of Alexandria insisted on the co-eternity and co-equality of Father and Son. Constantine convened perhaps 300 bishops at Nicaea in May-June 325 CE. He presided personally — a layman directing a theological assembly of churchmen — a precedent of immense historical significance. He reportedly opened the proceedings by burning, unread, the written grievances bishops had against each other. The council produced the Nicene Creed, declaring the Son 'of one substance (homoousios) with the Father' — a Greek philosophical term that itself became the centre of fresh controversy. Arius was condemned and exiled; his writings were ordered burned. In practice the controversy did not end. Constantius II, Constantine's son, favoured Arianism. Germanic tribes converted to Arian Christianity. The eastern empire would argue about the 'one substance' formula for centuries. But Nicaea established the template: councils summoned by emperors would define Christian doctrine.
- Year: 325 CE
- Category: Cultural
