The Fourth Council of Constantinople, the eighth Catholic Ecumenical Council, was convened to discuss the patriarchate of Photios I of Constantinople. Fourth Council of Constantinople (Catholic Church): The Fourth Council of Constantinople was the eighth ecumenical council of the Catholic Church held in Constantinople from 5 October 869, to 28 February 870. It was attended by over 103 bishops. In contrast, the pro-Photian council of 879–80 was attended by 383 bishops. The Council met in ten sessions from October 869 to February 870 and issued 27 canons. October 5, 869. Wiki link