The thickly populated parts of the present day Nagaon, earlier speltas Nowgong, were amongst the chosen targets of violence during the subsequent Burmese rule in the late 1810s. There was no leadership to organize resistance movement against the Burmese. The people heaved a sigh of relief when the British came down heavily on the Burmese and compelled them to withdraw from Assam. Following the treaty of Yandaboo in 1826, this area of the province passed off silently into the hands of the British. Nagaon was carved out as a separate district administrative unit in 1832. It took a couple of years before the British finally settled on the present site on the bank of the Kollong River as the district headquarters in 1839. The district headquarters was called Nagaon and gradually it emerged into a town. It became a municipality in 1893.
The eastern, western and southern segments of the newly organized district were once ruled by different small-time feudal kings or their agents. An extensive and undulating plain intersected by big and small hills and rivers - the geography of the segments determined who their masters ought to be. The residual effects of the rule of the Bara Bhuyans were imaginatively utilised and reorganised by Momai Tamuli Barphukana, an intrepid officer of the Ahom king Pratap Singha in the first half of the seventeenth century. This area, until then, was more of strategic than administrative concern. A newly organized village system - hence called "Nagaon", 'Na' meaning new.