Pope John VIII was the bishop of Rome and ruler of the Papal States from 14 December 872 to his death. He is often considered one of the ablest popes of the 9th century.
Posthumous miniature of John VIII, 14th century
John VIII's letter to Svatopluk I of Moravia
An 876 bull of John VIII
Cyril and Methodius were brothers, Byzantine Christian theologians and missionaries. For their work evangelizing the Slavs, they are known as the "Apostles to the Slavs".
"Saints Cyril and Methodius holding the Cyrillic alphabet," a mural by Bulgarian iconographer Z. Zograf, 1848, Troyan Monastery
Cyril and Methodius, painting by Jan Matejko, 1885
Saints Cyril and Methodius in Rome. Fresco in San Clemente
The Baška tablet is an early example of the Glagolitic from Croatia