In the 16th century Darrang was subject to the Koch king of Kamarupa, Nara Narayan, and on the division of his dominions among his heirs passed to an independent line of rajas. Early in the 17th century the raja Bali Narayan invoked the aid of the Ahoms of Upper Assam against the Muslim invaders; after his defeat and death in 1637 the Ahoms dominated the whole district. About 1785 the Darrang rajas took advantage of the decay of the Ahom kingdom to try and re-establish their independence, but they were defeated by a British expedition in 1792, and in 1826 Darrang, with the rest of Assam, passed under British control.
There are four Assam Legislative Assembly constituencies in this district: Kalaigaon, Sipajhar, Mangaldoi, and Dalgaon. Mangaldoi is designated for scheduled castes. All four are in the Mangaldoi Lok Sabha constituency.
According to the 2011 census Darrang district has a population of 928,500, roughly equal to the nation of Fiji or the US state of Delaware. This gives it a ranking of 463rd in India (out of a total of 640). The district has a population density of 586 inhabitants per square kilometre (1,520/sq mi) . Its population growth rate over the decade 2001-2011 was 19.51%. Darrang has a sex ratio of 954 females for every 1000 males, and a literacy rate of 63.08%.