Kamrup district (Assamese: কামৰূপ জিলা) is an administrative district in the state of Assam in India, named after Kamarupa, by which present Assam state and its adjoining areas are known in ancient times. The district, however, is now a part of Lower Assam, with unique culture and Kamrupi language, sharing the same with Nalbari and Barpeta, as being part of undivided Kamrup in 1980s.
The administrative district of Kamrup was first constituted from the western portion of the Ahom kingdom that the British acquired following the Treaty of Yandaboo of 1826. The western boundary of this district, the Manas River, had been the western boundary of the Ahom kingdom since 1682. The eastern boundary of this district was the Barnadi river, the Mughal-Ahom boundary first delineated in the Treaty of Asurar Ali of 1639. After 1826 the British administered the newly acquired regions via two commissioners: the Senior Commissioner who administered the "North-East of Rangpur" (largely the undivided Goalpara) in addition to the newly acquired region between Manas river and Biswanath; and the Junior Commissioner, who administered the region to the east of Biswanath. In March 1833 the British established district administration in the region west of the Dhansiri river, with the Kamrup district originally envisaged as two separate districts among 3 others: the six parganas largely co-terminus with present-day Barpeta and Nagarberra; and the twenty parganas in the north and six duars in the south. Each district were to be administered by a Principal Assistant, deputed by a Junior Assistant. But due to a paucity of funds, the six pargana region had only a Junior Assistant, and by 1836, the Kamrup district acquired its "undivided" form and name. After the independence of India in 1947 the "undivided" Kamrup district was further divided into the present Barpeta (1983), Nalbari (1985), Kamrup Metropolitan (2003) districts with the remaining portion retaining the name Kamrup.
The history of the (undivided) Kamrup district dates backs to the 4th century under Kamarupa Kingdom. The capitals of Varman Dynasty and Pala Dynasty namely Pragjyotishpura and Durjaya were in Kamrup, whereas the capital of the Mlechchha dynasty was in the (undivided) Darrang district.
Medieval times seen the period when Kamrup became battleground of different scrambling western and eastern powers. Banikanta Kakati says: