It was during the Mleccha dynasty or the line of Salastambha (from the last part of the 7th Century A.D. to the 10th century A.D), that the city was known as Haruppesvera or Hadapervara or Hadapesvara or Hatapesvara. The Tezpur Rock Inscriptions of Harjar Varma is of 829-30 A.D. The Tezpur and the Parbatia Copper Plates of Vanamats (middle of the 9th century A.D.), the Bargaon Grant of Ratnapala (circa 1035 A.D.) also reflect the city’s historical importance. Da-parbatia Door frame located at Da-parbatia near Tezpur is regarded as one of the excellent pieces of monumental art in stone in Assam. Although the city lost its importance during the medieval era, it was soon to regain it when the British came. Considering its strategic importance the colonial rulers first made it in to a garrison town. Gradually it became an important centre of trade and commerce, used as a river port for the surrounding tea gardens and other colonial commercial ventures in the hinterland. In 1835, Tezpur became headquarter of Darrang District. In the 1962 Chinese aggression, the city faced the apprehension of invasion, and bears a Memorial near the Circuit House as a testimony of that. In 1983, the Darrang District was partitioned, and Tezpur became the headquarter of Sonitpur District.
Sir Edward A. Gait ( 1897) had made reference to the nine line inscription of Harjjar Varma in his ‘’A History of Assam.’’ The inscription is the first recorded history of Assam and dates back to 829 A.D. The inscription was found engraved on a massive stone some two kms away from Tezpur town situated near a temple called Rudrapad.
Salastambha dynasty ruled Kamrupa from seventh to Tenth century A.D. The accurate boundary of their kingdom is debatable. But the erstwhile Darrang was certainly a part of the kingdom. They shifted their capital from Pragjyotishpur to Haruppeswara, or Hatappeswara- the present day Tezpur. The famous King of the dynasty Harjjar Varma, besides other things had excavated a large pond in 70 acres of land, later came to be known as Hajara Pukhuri ( Harjjara Pukhuri ).Pal dynasty ruled Haruppeswara till the 12th century. The most famous ruler of the Pal dynasty was Brahmapal.
After the Pal dynasty’’ the royal dominance of the Koch Kings in the west and the Ahoms in the east started growing. During the 14th and 15th century a large part of the western bank of Brahmaputra from Singri in the west and Sootea in the east was ruled by the Bara-Bhuyans. The great saint poet Sri Sri Shankardeva belonged to Bara-Bhuyan family, who settled at Rowta in Darrang District. The Ahom King Suhungmung alias Dihingia Raja occupied the territories of the Bara-Bhuyans on the north in 1505 A.D.The Koch King Biswa Sinha rose to power in 1515 A.D. King Naranarayana who ascended the thorne in about 1540 A. D. divided his Kingdom into two parts. He had given the eastern part to the son of his brother Chilarai and the western part of the kingdom to his own son Lakshminarayana . But soon after their ascension as kings, fatricidal war broke out and Lakshminarayana sought refuge with the Mughals which eventually led to invasion of Kamrup by the Mughals. Balinarayana, one of the brothers of Pariksitnarayana fled away to Gorgaon to seek the help of the Ahom king Swargadew Pratapsingha. Pratapsingha christened Balinarayana as Dharmanarayana, made him the king of Darrang and declared war against the the Mughals (1616-1637 A.D.). The Ahoms defeated the mighty Mughals in the Bharali war and re-occupied Darrang from the Mughals. King Dharmanarayana made supreme sacrifice in Singari war in 1638. His son Sundarnarayana ascended the throne and became the king of Darrang.(excluding Tezpur). On the otherhand, the Ahoms ruled the eastern part of Darrang ( present Sonitpur) through Kalia Bhomora Borphukan, stationed at Kaliabor. The Ahom Kings resettled many people in the southern part of Brahmaputra.