Historic sources record the Slavic peoples rather late. The Slavs themselves could not leave any trace about their distant past as they did not develop literacy. Furthermore, they were not of much interest to the historians who were writing in Greek and Latin, as the Slavs lived in remote regions and were not of a threat to the Roman Empire borders.
Then, things started to change when the Slavs were gradually approaching the Balkan peninsula. The process of their settling on the Balkans started in the 6th century, when those living at that time on the left bank of the Danube, along with rather superior Avars, made looting raids on the Byzantine territory. Final Slavic settling on the Balkans ended in the first half of the 7thcentury, when the Serbs and Croats arrived and generally a great number of Slavic people settled in the region. The Avars, living in their quite powerful land in Pannonia, were breaking through even to Salonika. The Avars and the Slavs besieged Salonika and in 626 even the Byzantine capital, Constantinople. With time, the Slavs got rid of the Avar influence.
For two hundred years, the Slavic peoples spread around the Balkans. In the 9th century, the first Balkan Slavs states came about.
The first written language was the Old Slavic, based upon the language spoken by the Macedonian Slavs living around Salonika in the 9th century. The Old Slavic came about as a liturgical language, and the first books written in that language were the service books. The old texts refer to the language simply as Slavic. Prior to an alphabet devised by the Christian missionaries Cyril and Methodius, the Old Slavs had not had any written sources, but used just “lines and notches”.
RELIGION AND TRADITION
The Slavs adopted Christianity in the 9th century. Before that their religion was polytheistic, but no records on it were ever left. It is assumed that actually there was no one common religion among the Slavs, as even before they came to the Balkans, each tribe had had their own idols. The earliest Slavic deities recorded were Pеrun and Vеlеs. These deities remained as the principal ones among the South Slavs after they had settled in the Balkans. Also a god Dabog is mentioned. However, no traces of any shrines have ever been found and it is not known whether there were any priests, certain cults or rituals.
Art, in its trues sense, in Slavs on the Balkans starts only after they were Christianised. The only artistic form before that could have been the old Slavic mythology or religious meaning.