The Fourth Council of Constantinople is considered an ecumenical council by Roman Catholics and met from October 5, 869 to February 28, 870.

It was called by Emperor Basil I the Macedonian and Pope Adrian II. It deposed and condemned Photius as patriarch and, of the four Eastern patriarchates, ranked Constantinople before Alexandria, Antioch, and Jerusalem. Photius is now considered a saint of the Eastern Orthodox Church; in part for having refused to acquiesce to the decision of this council and what the Eastern Orthodox consider to have been overweening monarchical aspirations on

Photius is also considered a saint by Eastern Rite Catholics in the same manner as he is by the Orthodox. Among Eastern Catholics, he is remembered for the virtues of his personal life and his remarkable talents, even genius, and the wide range of his intellectual aptitudes.

The "Other" Fourth Council of Constantinople

Many theologians (and not a few bishops; see Encyclical of the Eastern Patriarchs) within the Orthodox Church consider the council of 869-870 to have been a robber council and instead recognize the reunion council held at Constantinople in 879-880 as being the Eighth Ecumenical Council. This latter council was originally accepted and fully endorsed by Rome (whose legates were present), who in the 11th century repudiated it and retroactively regarded the council of 869-870 to be ecumenical. The council of 879-880 restored St. Photius to his see and anathematized any who altered the Nicene-Constantinopolitan Creed (thus condemning the Filioque).

For more on the council of 879-880, see also:

• by Protopresbyter George Dion Dragas
• 4. konstantinopolský koncil

Viertes Konzil von Konstantinopel