Being the northern frontier district skirting Koch-Behar, numerous colonies of Afghan and Mughal chiefs were planted there under the feudal system, with large jagir lands under each. Bhim Narain, Rajah of Kuch Behar used to regularly pay tribute to the Emperor Shah Jahan, but that during the chaos which arose owing to Emperor's illness, and after the death of Sultan Shuja in February 1661 there was anarchy in the region. Bhim Narain became daring and refused to pay tribute and with a large force attacked Ghoraghat. In the same year (on 17th Rabiul-Awwal 1072 A.H) the Khan-i-Khinan (Muazzam Khan) set out from Khizapur (which has been identified to be a place close to Narayanganj) with war-vessels, for the conquest of Koch-Behar. The Rajah (Bhim Narain) fled to Bhutan, his minister Bholanath fled to the Murang, and the Imperialists stormed Kuch-Behar town, and named it Alamgirnagar.