Second Council of Nicaea

The Second Council of Nicaea is recognized as the last of the first seven ecumenical councils by both West and East. Orthodox, Catholics, and Old Catholics unanimously recognize it; Protestant opinions on it are varied.

It met in AD 787 in Nicaea (site of the First Council of Nicaea; present-day İznik in Turkey) to restore the use and veneration of icons (or, holy images), which had been suppressed by imperial edict inside the Byzantine Empire during the reign of Leo III (717–741). His son, Constantine V (741–775), had held the Council of Hieria to make the suppression official.

The veneration of icons had been banned by Byzantine Emperor Constantine V and supported by his Council of Hieria (754 AD), which had described itself as the seventh ecumenical council. The Council of Hieria was overturned by the Second Council of Nicaea only 33 years later, and has also been rejected by Catholic and Orthodox churches, since none of the five major patriarchs were represented. The emperor's vigorous enforcement of the ban included persecution of those who venerated icons and monks in general. There were also political overtones to the persecution—images of emperors were still allowed by Constantine, which some opponents saw as an attempt to give wider authority to imperial power than to the saints and bishops. Constantine's iconoclastic tendencies were shared by Constantine's son, Leo IV. After the latter's early death, his widow, Irene of Athens, as regent for her son, began its restoration, moved thereto by personal inclination and political considerations.