Marinus I

Pope Marinus I ( ; died 15 May 884) was the bishop of Rome and leader of the Papal States from 882 until his death on 15 May 884. Controversially at the time, he was already a bishop when he became pope, and had served as papal legate to Constantinople. He was also erroneously called Pope Martin II leading to the second pope named Martin to take the name Martin IV.

Ecclesiastical career Diplomat to the East Born at Gallese, Marinus was the son of a priest. He would become an expert on relations with the Eastern church, starting this path when he assisted as subdeacon the welcome of ambassadors of emperor Michael III in 860. He was ordained as a deacon by Pope Nicholas I and then sent in 866 to Constantinople to discuss the religious leadership over the newly converted Bulgarians though the embassy was turned back at the Byzantine border. During that time, he also served as treasurer to the Holy See. This papal election was controversial because Marinus had already been consecrated as bishop of Caere; at the time, a bishop was expected never to move to another see. Among his first acts as pope were the reinstatement of Formosus as cardinal bishop of Portus and the anathematizing of Photius I. Due to his respect for Alfred the Great (r. 871–899), he freed the Anglo-Saxons of the Schola Anglorum in Rome from tribute and taxation. He died in May 884 and was buried in St. Peter's basilica in Rome, his successor being Adrian III.