ABSTRACT
Nicholas I was pope from 858 to 867. His importance began in his own times because of his extended and high view of his office. His principles involved him in three important areas: relations with the Carolingians (especially the affair of Lothar’s divorce); conflict with bishops and church councils in the West; battle with Archbishop John of Ravenna and relations with the eastern church, especially over the questions of Photius’s right to the patriarchate of Constantinople and the attempt to bring Bulgaria into the Roman orbit.
