The Koch (Pron:kɒʧ) dynasty of Assam and Bengal, named after the Koch tribe, emerged as the dominant ruling house in the Kamata kingdom in 1515 after the fall of the Khen dynasty in 1498. The first of the Koch kings, Viswa Singha and then his sons, Nara Narayan as the subsequent king and Chilarai as the general, soon occupied the western portion of the erstwhile Kamarupa Kingdom as well as some regions of south Assam. The dynasty forked for the first time into two major branches that controlled Koch Bihar and Koch Hajo. Koch Bihar became a vassal of the Mughals, whereas Koch Hajo came under Ahom control and was subsequently absorbed. Koch Bihar became a princely state during British rule and was absorbed after Indian independence. A third branch of this dynasty at Khaspur disappeared into the Kachari kingdom.