Councils and Their Canons

First Ecumenical Council: Nicaea I (325)

Convened by Emperor Constantine to address the Arian heresy (Christ is a created being). Affirmed the Son is 'homoousios' (consubstantial) with the Father. Produced the first part of the Nicene Creed. Established the date of Pascha (Easter). 318 bishops attended.

Sources

Eusebius, Life of Constantine III.6-14 NPNF
St. Athanasius, De Decretis NPNF
Socrates Scholasticus, Church History I.8 NPNF

Connections

Arianism
Emperor Constantine the Great
Homoousios (Consubstantial)
Nicene-Constantinopolitan Creed
St. Athanasius the Great (c. 296-373)
St. Nicholas of Myra (c. 270-343)
The Holy Trinity

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