An ancient city in Bithynia; founded in the 4th century BC and flourished under the Romans; the Nicene Creed was adopted there in 325.

The seventh ecumenical council in 787 which refuted iconoclasm and regulated the veneration of holy images.

synonym: Second Council of Nicaea.

The first ecumenical council in 325 which produced the wording of the Nicene Creed and condemned the heresy of Arianism.

synonym: First Council of Nicaea.