Kuber was a Bulgar leader who, according to the Miracles of Saint Demetrius, liberated a mixed Bulgar and Byzantine Christian population in the 670s, whose ancestors had been transferred from the Eastern Roman Empire to the Syrmia region in Pannonia by the Avars 60 years earlier. According to a scholarly theory, he was a son of Kubrat, brother of Khan Asparukh and member of the Dulo clan.