Council of Nicaea

The First Council of Nicaea (AD 325), convened by Emperor Constantine, brought together the bishops of the Roman Empire to resolve the Arian controversy. It affirmed the consubstantiality of Christ with the Father, adopted the Nicene Creed still used today, set the date of Easter and strengthened the alliance between the Church and the Roman Empire, thus laying the doctrinal and liturgical foundations of Christianity.

Level: Intermediate Level: Intermediate

The Council of Nicaea (325) established liturgical rules that enabled Dionysius Exiguus to set Jesus' birth on 25 December. This date was chosen for symbolic reasons and to replace pagan winter solstice festivals, notably Sol Invictus. Although not historically verifiable, 25 December became the official date of Christmas in the Western Church.

Level: Intermediate Level: Intermediate