When paganism had disappeared, the Southern-Slavonic legends received many elements from the Greeks and Romans. There are references to the Emperors Trajan and Diocletian as well as to mythical personages. In the Balkans, Trajan is often confused with the Greek king Midas. In the year 1433 Chevalier Bertrandon de la Broquière heard from the Greeks at Trajanople that this city had been built by the Emperor Trajan, who had goat's ears. The historian Tzetzes also mentions that emperor's goat's ears otia tragou. In Serbian legends the Emperor Trajan seems also to be confused with Dædalus, for he is given war-wings in addition to the ears.
To the cycle of mediæval myths we owe also the djins (giants) who dwelt in caverns, and who are known by the Turkish name div--originally Persian. Notable of the divs were those having only one eye--who may be called a variety of cyclops--mentioned also in Bulgarian, Croatian and Slovenian mythology. On the shores of the river Moratcha, in Montenegro, there is a meadow called 'Psoglavlya Livada' with a cavern in which such creatures are said to have lived at one time.
When the pagan Slavs occupied the Roman provinces, the Christian region was limited to parts of the Byzantine provinces. In Dalmatia after the fall of Salona, the archbishopric of Salona was transferred to Spalato (Splyet), but in the papal bulls of the ninth century it continued always to be styled Salonitana ecclesia, and it claimed jurisdiction over the entire lands as far as the Danube.
According to Constantine Porphyrogenete, the Serbians adopted the Christian faith at two different periods, first during the reign of the Emperor Heraclius, who had requested the Pope to send a number of priests to convert those peoples to the Christian faith. It is well known, however, that the Slavs in Dalmatia even during the reign of Pope John IV (640-642) remained pagans. No doubt Christianity spread gradually from the Roman cities of Dalmatia to the various Slav provinces. The Croatians already belonged to the Roman Church at the time when its priests were converting the Serbians to Christianity between the years 642 and 731, i.e., after the death of Pope John IV and before Leon of Isauria had broken off his relations with Rome.