It came to be associated with the historical Kamarupa[1] 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.

[2] The identification with the mythical Naraka/Bhagadatta lineage continued to be used by the Mlechchhas and Palas for roughly similar purposes.

[4] The first mentions of this kingdom are found in the Ramayana and the Mahabharata, in sections not written much earlier than the first century.

[6] In Aswamedha-Parva of the latter, Arjuna defeated Vajradatta of Pragjyotisha in a three-day battle near Punjab in the Lower Indus Valley;[7] the Harivamsa Parva features multiple mentions as well.

A popular mythical narrative claims that Jyotisha is the sanskritised form of Zuhthis, who were (apparently) the first migrants to Assam from China — this has little historical evidence in support.