The Sclaveni or Sklabenoi were early Slavic tribes that raided, invaded and settled in the Balkans in the Early Middle Ages and eventually became one of the progenitors of modern South Slavs. They were mentioned by early Byzantine chroniclers as barbarians having appeared at the Byzantine borders along with the Antes, another Slavic group. The Sclaveni were differentiated from the Antes and Wends ; however, they were described as kin. Eventually, most South Slavic tribes accepted Byzantine or Frankish suzerainty, and came under their cultural influences and Chalcedonian Christianity. The term was widely used as a general catch-all term until the emergence of separate tribal names by the 10th century.

The early Slavs were an Indo-European peoples who lived during the Migration Period and the Early Middle Ages in Central, Eastern and Southeast Europe and established the foundations for the Slavic nations through the Slavic states of the Early and High Middle Ages. The Slavs' original homeland is still a matter of debate due to a lack of historical records; however, scholars believe that it was in Eastern Europe, with Polesia being the most commonly accepted location.