cardinal as a potential rival. In 883, John VIII's successor, Marinus I, restored Formosus to his suburbicarian diocese of Portus. Following the reigns of Marinus, Adrian III (884–885) and Stephen V (885–891), Formosus was unanimously elected pope on 6 October 891. Papacy Shortly after his election, Formosus was asked to intervene in the Patriarchate of Constantinople, where Photius I had been ejected and Stephen I, the son of Emperor Basil I, had taken the office. Formosus refused to reinstate those who had been ordained by Photius, as his predecessor, Stephen V, had nullified all of Photius' ordinations. However, the Eastern bishops determined to recognize Photius' ordinations nonetheless. Formosus also immediately immersed himself in the dispute between Odo of Paris and Charles the Simple for the French throne. Siding with Charles, Formosus zealously exhorted Odo to cede the throne to Charles, to no avail. Formosus was deeply distrustful of Guy III of Spoleto, the reigning emperor, and began looking for support against him. To bolster his position, Guy forced Formosus to crown his son Lambert as co-emperor in April 892. The following year, however, Formosus persuaded Arnulf of Carinthia to advance to Rome and liberate Italy from Guy's control. In 894, Arnulf's army occupied all the country north of the Po River. Guy died in December, leaving his son Lambert in the care of his mother, Agiltrude, an opponent of the Carolingians. In autumn 895 Arnulf undertook his second Italian campaign, progressing to Rome by February and seizing the city from Agiltrude by force on February 21. The following day, Formosus crowned Arnulf as emperor in St. Peter's Basilica. The new emperor moved against Spoleto but was struck with paralysis on the way and was unable to continue the campaign. During his papacy, Formosus also had to contend with the Saracens, who were attacking Lazio. On 4 April 896, Formosus died. He was succeeded by Boniface VI, whose papacy lasted 15 days. Legacy Stephen VI, the successor of Boniface VI, influenced by Lambert and Agiltrude, sat in judgment of Formosus in 897, in what is known as the Cadaver Synod. The corpse was disinterred, clad in papal vestments, and seated on a throne to face all the charges from John VIII. The verdict was that the deceased had been unworthy of the pontificate. The was applied to Formosus, all his measures and acts were annulled, and the orders conferred by him