Indo-Aryan migration to Assam
first migrated to Assam in approximately the fifth century BCE. They came from the Gangetic Plains into a region already inhabited by people who spoke Austroasiatic and Tibeto-Burman languages.
Pre-Indo-Aryan Assam
The 8th- to 6th-century BCE text, Shatapatha Brahmana, describes the Sanskritization of East India up to the Karatoya river, the western boundary of the historic Kamarupa kingdom. Though the Sankhyayana Grihasamgraha is said to mention 'Pragjyotisha' as the land of sunrise, this has been shown to be a wrong attribution. Archaeologically too, the Northern Black Polished Ware, a pottery style associated with the development of the first large states in Northern India, reached the Karatoya only by the 2nd century BCE. Therefore, it is claimed that the spread of Indo-Aryans into Assam cannot be pushed beyond the 5th century BCE.It is also significant that neither early Buddhist sources, nor Ashokan epigraphs mention the Assam region. The Periplus of the Erythraean Sea and Ptolemy's Geography refer to the Cachar of Barak Valley in Assam, Sylhet and Tripura as Kirrhadia, after the Kirata people. A reference to Lauhitya in Kautilya's Arthashastra is identified by commentators with the Brahmaputra Valley, though the Arthashastra in its current form is dated to the early centuries of CE, and the commentaries to even later.
It appears that the Assam region became a punya bhumi, a region that did not require a Hindu purification ceremony, by the post Gupta period.
Introduction of Indo-Aryan
The earliest historical mention of this region in Indo-Aryan comes from Samudragupta's Allahabad inscription, where two kingdoms from the region—Kamarupa and Davaka—are mentioned. The earliest evidence of Indo-Aryan in Assam are the 5th-century Umachal and Nagajari-Khanikargaon rock inscriptions.Brahman settlements
Two inscriptions of Bhaskaravarman on copper plates are re-issues of grants to Brahmins to settle in parts of the Kamarupa kingdom during the reign of Bhutivarman. This policy, of the local kings settling Brahmans from other places in the kingdom, was a common policy of all Kamarupa kings that gave rise to pockets of Brahmanic influence. From the inscriptions it can be made out that the Brahman donees came to Assam from present-day Bangladesh, Bengal, Bihar and Uttar Pradesh. Indo-Aryan presence and influence became significant by the 7th century. Whereas the early grants had natural boundaries such as trees or water, those from the later Pala rulers, increasingly bordered on other granted lands, thereby indicating that the pockets of Indo-Aryan settlements were becoming contiguous. Nevertheless, the process of Sanskritization was never complete in Assam, and significant sections remained outside Brahmanic influence.Languages
The subsequent Kamarupa inscriptions, written in Sanskrit, suggest that a majority of the Indo-Aryan immigrants spoke Kamarupi Prakrit the precursor of Assamese language and the Proto-Kamata; and that the learned few knew Sanskrit. Sanskrit was the liturgical language of Hinduism and the state language of Kamarupa; and Assamese became a link language, accepted as a second language by some of the aboriginal peoples; over time, it became the first language for many. In return, Assamese acquired linguistic features of the native speakers. The writing shows an evolution from the early Gupta script towards modern Assamese script. The latest examples, such as the Kanai-boroxiboa inscription, use a proto-Assamese script.The Magadha empire was founded by Bimbisara in the 4th century BCE. About this time, or after, the whole of northern Bengal, to the south of the Jalpaiguri district and west of the Trisrota, was absorbed in the Maurya empire together with the Tamralipti region in the south west. The Mauryan empire of Ashoka undoubtedly included northern Bengal between the Teesta and the Kosi rivers, for within this area stupas erected by Ashoka were found by Xuanzang in the 7th century CE. This area continued to be included in the Magadha empire at least till the 6th century CE. During the rule of the Imperial Guptas it was known as Pundravardhana, whose inhabitants then generally spoke non-Aryan languages.
To the east and north of Pundravardhana, Kamarupa continued as an independent kingdom, ruled over by an indigenous line of kings who traced descent from heroes named in the epics as Naraka, Bhagadatta and Vajradatta. Indo-Aryan accounts of the region between 500 BCE and 4th century CE come from the revised Mahabharata and Puranas, and the c. 10th-century Kalika Purana. The accounts in these Hindu texts conflict with each other, but the Kamarupa dynasties claimed ancestries going back thousands of years. It is supposed that bands of Indo-Aryan people moved from Magadha to the forested regions of the Brahmaputra valley; the leaders of these bands are remembered in later myths as Parashurama, Bashishtha and Naraka. The Kalika Purana reports that Naraka displaced an indigenous Danava dynasty.
Sanskritisation under the Kamarupa kings
In the historic period, the Kamarupa kings encouraged immigration from North India, and settled Brahmins as "islands of private domains in a sea of communally held tribal lands of shifting cultivation". One such settlement was Habung, where Ratnapal of the Pala dynasty of Kamarupa settled Brahmins in c. the 10th century, then known as Ha-Vrnga Vishaya.Though traditional accounts claim that the kings of Assam were Indo-Aryan, modern scholarship is not clear.
Sanskritization, was a process that occurred simultaneously with "deshification" in Assam.
From epigraphic records, so far brought to light, it is possible to trace an almost unbroken genealogy of these kings from about the middle of the 4th century CE down to the 12th century or a period of nearly nine hundred years. Very few of the old Hindu kingdoms in India can present such unique genealogical records covering such a long period. No less than twelve copperplate inscriptions, inscribed seals and rock-inscriptions recorded by various kings of Kamarupa during this period have been discovered and deciphered. Epigraphic records left by the famous Gupta emperor Samudra Gupta, Yasodharman, king of Malwa, who was a famous conqueror, Adityasena, who belonged to the line of Later Guptas of Magadha, Jayadeva, a well-known king of Nepal and some of the Pala kings and Sena kings of Bengal provide useful material for the history of Kamarupa during this period. Other materials include Raghuvaugsa of Kalidasa, the Chinese writers, the Harsha-Charita of Banabhatta, the Raja-tarangini of Kahlan, and translations from Tibetan records.
| King | Great deed | Sin or fault | Punishment | Brahmanical vs. Tribal tension |
| Naraka | Found kingdom of Kamarupa and Worship Kamakhya | Make pact with tribal king | Goddess hidden from him | Pact with tribal king |
| Bana | Builds stairway to kamakhya temple | Demands vision of the goddess | Goddess hidden from him | Demonic tribal king |
| Salastambha | Conquest of Kamarupa | Unknown | Cursed to be mleccha | Founds mleccha dynasty |
| Visva Singha | Rediscover Kamakhya temple | Mother offends holy man | Mother is a mleccha | War against tribal kings, child of god and a mleccha |
| Naranarayana Singha | Rebuild the temple | Demands a vision of goddess | Descendents can't visit the temple | Defeats tribal kings but allowed soldier to worship in tribal mode |
| Rudra Singha | Patronize brahmins and build temples | Tribal origin, offends priest | Dies without receiving initiation | Non-Hindu tribal origin |