Pope Nicholas I

Pope Nicholas I reigned from 858 to 867, and is remembered as a consolidator of Papal authority and power. He refused to grant an annulment to Lothar II from Theutberga so that Lothar could marry his mistress Waldrada; when a Council pronounced in favor of annulment Nicholas I declared the Council to be deposed, its messengers excommunicated, and its decisions void. Despite pressure from the Carolingians, who laid siege to Rome, his decision held. During his reign, relations with the Byzantine Empire soured over his support for Ignatius as Patriarch of Constantinople, who had been removed and Photius appointed to replace him.

Preceded by: Pope Benedict III

List of popes

Succeeded by: Pope Adrian II