When the happy tidings of what they had done reached Rome, the Supreme Pontiff the holy Nicholas I, commanded these excellent brethren to come to Rome. When they started for Rome they brought with them the relics of the supreme Pontiff the holy Clement I which Cyril had discovered at Cherson. On hearing of their approach Adrian II, who had succeeded to the Papacy upon the death of Nicholas, went forth to meet them accompanied by the clergy and people with every sign of honour. Then Cyril and Methodius gave to the Supreme Pontiff in the presence of the clergy an account of the Apostolic office which they had discharged in so holy and toilsome a manner. When it was made blame to them by some enviers that they had used the Slavonic language for the purposes of public worship, they stated their reasons with such clearness and force that the Pontiff and clergy praised and approved them. When they had both taken an oath that they would remain in the faith of blessed Peter and of the Roman Pontiffs, they were consecrated bishops by Adrian, but it was the Will of God that Cyril, old in grace rather than in years, should close his life at Rome. His dead body received a public funeral, and was laid in the tomb which Adrian had built for himself, but it was afterwards brought to St. Clement's and buried hard by the ashes of that martyr. As it was carried through the city with joyful psalm-singing, it seemed as though the procession were rather that of a triumph than that of a funeral, and that the Roman people were offering heavenly honour to some eminent saint. Methodius went back to Moravia, and there became from his whole soul a pattern to his flock, and from day to day more zealous in the service of Catholicism. He confirmed the Pannonians, the Bulgarians, and the Dalmatians in the Christian religion, and laboured much to bring the Corinthians to the worship of the one true God.
Methodius was again accused before John VIII, the successor of Adrian, of unsoundness in faith, and transgression of the traditions of the elders; he was summoned to Rome, and there easily proved, in the presence of John and of some Bishops and clergy of the city, that he had himself always firmly held the Catholic faith, and had carefully taught it to others, and that as regarded the use of the Slavonic language for public worship, he had acted lawfully from certain reasons, and the permission of Pope Adrian, and in nowise contrary to holy writ. The Pontiff therefore in this matter concurred with Methodius, and confirmed even in writing his archiepiscopal authority and his mission among the Slavs. Methodius therefore went back to Moravia and resumed more earnestly than before the task committed to him, for the which also he cheerfully suffered exile. He converted the Prince of the Bohemians and his wife, and spread the Christian name far and wide among that people. He carried the light of the Gospel into Poland, and according to some writers, after establishing the see of Lemberg, went into Muscovy properly so called and established the see of Kiev. At the last he returned into Moravia, and when he felt that he was about to go the way of all flesh he named his own successor, exhorted the clergy and people for the last time to good living, and then calmly departed that life which had been to him a path to heaven. As Rome had honoured Cyril in his death, so did Moravia honour Methodius. The festival of these Saints, which had long been observed among the Slav nations, the Supreme Pontiff Leo XIII observed to be kept throughout the Universal Church with a special office and Mass.