Church councils are formal meetings of bishops and representatives of several
churches who are brought together to regulate points of doctrine or discipline. The meetings may be of a single ecclesiastical community or may involve an
ecclesiastical province, a nation or other civil region, or the whole Church. Some of those convoked from the Church as a whole have been recognized as
ecumenical councils and are considered particularly authoritative. The first ecumenical council is
that of Nicaea, called by the Emperor Constantine in 325.