The modern Assam was known as Kamarupa and Pragjotish during the ancient times.
Pragjotish was the capital of Kamarupa.
The Allahabad inscription of Samudragupta mentioned about the Davaka kingdom as the border state along with Kamarupa in this region.
The kingdom of Kamarupa was extended up to northern and western Bengal, and bordering lands of China as well as Davaka.
This region was ruled by a single dynasty from the time of Mahabharata up to the middle of the 7th century, till Bhaskaravarma.
The Kamarupa dynasty claims its descent from the Asura Naraka.
This Kamarupa dynasty is also known as ‘Bhauma’ (i. e. the son of Bhumi).
Asura Naraka had a son namely Bhagadatta who had taken part in the Mahabharata War.
The inscriptions of the dynasty proved that the king Bhagadatta and his successors ruled for about 3,000 years in Kamarupa prior to king Pushyavarma.
The king Pushyavarma was a contemporary of Samudragupta.
The 8th king, Bhutivarma had ruled in the mid of the 6th century is known for his own records.
The time period of the first king Pushyavarma had been fixed A.D. 350 approximately. He had acknowledged the supremacy of Samudragupta.
Pushyavarma assumed the title of ‘Maharajadhiraja’ and the ‘lord of Pragjotish’ as mentioned in the Nalanda seal.
The 7th king, Narayanavarma, performed horse sacrifices, which shows that he become independent of the Gupta Empire during the first half of the 6th century.
The 8th king Bhutivarma or Mahabhutivarma was a powerful king. He ruled in the middle of the 6th century A.D.
Kamarupa became a powerful kingdom during the reign of Bhutivarma.
During Bhutivarma’s reign kamrupa included the whole of the Brahmaputra valley and Sylhet and extended upto the Karatoya River in the west. It remains to be the traditional boundary of Kamarupa for a long time.
Chandramukhavarma, son of Bhutivarma, was not so known. However, his son Sthitavarma (grandson of Bhutivarma) had performed a horse sacrifice.
The king Susthitavarma mentioned in the Aphsada inscription of the later Gupta King Adityasen.
Mahasenagupta had defeated Susthitavarma on the banks of river Lauhitya (Brahmaputra).
Sasanka may be identified with the same Gauda king who defeated and imprisoned Supratisthitavarma and Bhaskaravarma soon after the death of their father Susthitavarma.
Supratishthitavarma had not yet ascended the throne. Both of them managed to escape from the prison of the Gauda king and Supratishthitavarma ruled for a short period. His brother, Bhaskaravarma, succeeded him.
Bhaskaravarma had been described in Harshacharita of Banabhatta. He was an ally of the king Harshavardhana.
Bhaskaravarma sent his ambassador Hamsavega with presents to have a coalition with Harsha.
The king of Kamarupa had been earlier defeated and imprisoned along with his elder brother by the king of Gauda. Therefore, this coalition was a good diplomatic move by the king of Kamarupa.
Rajyavardhana, the elder brother of Harsh was killed deceitfully by the same king of Gauda and Harsha had declared to destroy them. Therefore, this was a coalition between the two kings against their common enemy.
Banabhatta’s account has disturbed the chronological sequence of the events and therefore some confusion has cropped up about the history of the time.
The coalition force of Harsha and Bhaskaravarma defeated the Sasanka, king of Bengal and as a result of this Bhaskaravarma succeeded in occupying a large portion of Bengal.
Hiuen-Tsang mentioned in his account that Bhaskaravarma had great influence over the Buddhist monastery of Nalanda.
Hiuen-Tsang mentioned that King Bhaskaravarma sent a messenger to Silabhadra, the head of Nalanda monastery, to send the 'great pilgrim from China' to him. But this request was compiled only after a threat.
On the invitation, Hiuen-Tsang visited Kamarupa and stayed there for about a month. Thereafter, Harsha demanded from the king of Kamarupa to send back the Chinese pilgrim to his court. This also complied after a threat to Bhaskaravarma.
Bhaskaravarma met Harsha in person along with Hiuen-Tsang at Kajangala.
Bhaskaravarma also attended the great religious assembly called by Harsha at Kanauj and Prayaga.
Hiuen-Tsang’s account shows that Bhaskaravarma had control over north Bengal and also had influence over Nalanda in Bihar.
After the death of Bhaskaravarma, this ancient dynasty came to an end.
Later on, the Kamarupa kingdom was occupied by a Mlechchha ruler named Salastambha.
Names of a few successors of Salastambha are known, but no details are available about them.