It came to be associated with the historical Kamarupa after Bhaskaravarman of the Varman dynasty by drawing his lineage from Naraka/Bhagadatta of the legendary Pragjyotisha to bring his peripheral kingdom closer to mainland traditions at a time when he was emerging as a powerful king with interests in North India.
Bhaskaravarman, who belonged to the Varman dynasty, linked his lineage to the historical Kamarupa by tracing it back to Naraka/Bhagadatta from legendary Pragjyotisha. This move helped bring his kingdom closer to mainland traditions as he grew in power and expanded into North India.