The Pauranic sources like the Harivamsa, Vishnu Purana, Bhagavat Purana, and the Kalika Purana (Shastri 1993) referred to the legends of Naraka-Bhagadatta as the progenitor of the Aryans of this part of India. The Kailka Purana depicts the story of Narakasur. The text shows that Naraka was born of mother earth (bhumi) through Vishnu in his Boar incarnation. As born of earth (bhumi), Naraka came to known as Bhauma and it has observed that subsequently all ruling families of Pragjyotisha-Kamarupa claimed their descent from Naraka- Bhagadatta. The study of the early settlement pattern in Assam indicates that the majority of people belong to the Indo-Mongolian group of people along with Proto-Mongolian, Tibeto-Burmese, Proto-Austroloid, and Alpine group of people before the advent of Naraka-Bhagadatta. Recently, scholars have started a debate on the antiquity, origin, and continuity of Aryan way of life and mode of cultivation in the Northeastern India. Boruah (2007: 30) is of the opinion that the advent of Naraka makes a tentative demarcating line for the advent of Aryan culture in this land. It seems that Alpines were responsible for the spread of Aryan culture prior to the coming of Narkasur. Our extant sources, which are mainly the epigraphs, show that it was the Brahmanical class with their own social norms and behaviour had initiated the process of social change through a process of acculturation and assimilation amongst the local people.