The published book of Professor A.P. Lebedev is dedicated to a very important period in the history of Byzantium, in the life of the Byzantine and, in general, the Eastern Church. This period is associated with the activities of an outstanding church figure in Byzantine history - Patriarch Photius of Constantinople. The author sets the task to consider the history of the Councils of Constantinople in the middle of the 9th century. against the background of the struggle of the Western and Eastern churches in this era and the struggle unfolding in the Byzantine church of supporters of the ousted patriarch Ignatius and supporters of Photius.