Most of the known history of Dharmanagar is derived from the ancient Rajmala scripts, which is the ancient Royal chronicles of the Kings of Tripura written in the 14th century AD. Initially unrecorded, it was in circulation in the ancient Kokborok language, which is the language of the Tripura Kings before it was translated and edited into Bengali in the late 14th century by Pandit Likhan Chandra Ghosh and Pandit Kaliprasanna Sen, who were respected scholars of the time.
The origin of the name 'Dharmanagar' cannot be accurately traced back in time. The Rajmala refers to at least four known ancient kings whose names include the word 'Dharma'. So it remains a matter of speculation as to which king had lent his name to the town. Various uncovered documents however, indicate that the existence of Dharmanagar goes back deep into time. The Rajmala further indicates that the name 'Faticuli' was used to mean Dharmanagar back in those ancient times.
Dharmanagar becomes a district town from 26th OCT 2011.