The Slavs, like many other barbarian peoples, left their striking mark in Roman sources. The opinion about the Slavs and their customs and religion was not significantly different from the Byzantine opinion about all other migrating peoples. Thus, Byzantine writers viewed the Slavs as mere barbarians whose beliefs and practices of their paganism were inhumane and savage. In the writings of Pseudo-Caesarius, the Slavs are savages who “devour” women’s breasts for milk, and throw ill children against the rocks like rats. He also notes that the Slavs have several chiefs and that they regularly kill their chiefs. In order to further dehumanize the Slavs, he states that they call each other like wolves – howling.
In the writings of Procopius of Caesarea, we have new information about the Slavs. He compares the Slavs to the Antes (who are often thought to be either the same Slavic group or a Sarmatian tribe) stating that they have the same supreme god of lightning to whom they sacrifice cattle. This is certainly about the Slavic god Perun, whose memory has remained through certain toponyms and plants. Procopius writes that the Slavs do not know fate, that they worship fairies and that they know the abilities of witchcraft. According to Procopius, the Slavs live in miserable huts, often move and are very skilled warriors.
Although Procopius mentions democracy in Slavic society, another writer known to us as Pseudo-Mauritius states that Slavic society is very divided and that there is anarchy. Pseudo-Mauritius describes the Slavs as a free society that does not know slave ownership, and therefore sees no purpose in keeping prisoners too long. He described Slavic women as virtuous, in the sense that they would rather take their own lives than remain widows. Mauritius also describes the Slavs as very capable warriors who skillfully control rivers and swamps because they are constantly surrounded by them. From his writings, we learn that the Slavs respect cattle and are engaged in cattle breeding, and that is why he warns the Roman army to take good care of the cattle, especially the horses, from Slavic thieves. The Slavs will use all these qualities very skillfully, and by accepting Christianity, they will open the door to the final colonization of the Balkans. By accepting baptism, the hatred towards the Balkan Slavs will subside a little and the Slavs will become a dominant factor in the future history of the Balkan Peninsula.