Vitus, a native of Sicily, who was martyred during the emperor Diocletian's persecutions, is not well known among Orthodox Christians. However, his feast day, which is celebrated on June 15th, occupies an extremely important place in the minds of the Serbian people, as Vidovdan. At the end of the 19th century, Jovan Vučković, a learned priest, concluded that, for the Serbs, the significance of the feast of St. Vitus does not lie in any particular reverence for St. Vitus himself, but in the fact that the Battle of Kosovo took place on his feast day. Nevertheless, there are reliable testimonies that the Serbs did revere this martyr from Sicily, in the Middle Ages. The earliest is to be found in the menologion in the Miroslav Gospel, and St. Vitus is also recorded in hagiographic sources that appeared after the establishment of the autocephalous Serbian Church. We find the most frequent mention of him in the manuscript synaxaria of the so-called First recession of the Menologue of Basil II (from 13th and 14th centuries), and several 14th century menaions contain an akolouthia dedicated to St. Vitus.