The Koch dynasty (Pron: kɒʧ; 1515–1949) ruled parts of eastern Indian subcontinent in present-day Assam and Bengal. Biswa Singha established power in the erstwhile Kamata Kingdom which had emerged from the decaying Kamarupa Kingdom. The dynasty came to power by removing the Baro-Bhuyans, who had earlier removed the short-lived rule established by Alauddin Hussain Shah. The dynasty split into three among the descendants of Biswa Singha's three sons; two antagonistic branches Koch Bihar and Koch Hajo and a third branch at Khaspur. Koch Bihar aligned with the Mughals and the Koch Hajo branch broke up into various sub-branches under the Ahom kingdom. Koch Bihar became a princely state during British rule and was absorbed after Indian independence. The third branch at Khaspur disappeared into the Kachari kingdom. Raikat is a collateral branch of the Koch dynasty that claim descent from the Sisya Singha, the brother of Biswa Singha. Etymology The name Koch denotes a matrilineal ethnic group to which Biswa Singha's mother belonged; and the king as well as most of the population of the kingdom (Koch Bihar) belonged to the Koch community. History Historical background After the fall of the Pala dynasty of Kamarupa, the kingdom fractured into different domains in the 12th century. Sandhya, a ruler of Kamarupanagara (present-day North Guwahati) moved his capital further west to present-day North Bengal in the middle of the 13th century and the domain he ruled over came to be called Kamata kingdom. The buffer region, between the eastern kingdoms and Kamata was the domain of the Baro-Bhuyans chieftains. Alauddin Husain Shah of Gaur removed Nilambar of the Khen dynasty in 1498, occupied Kamata and placed his son Danyal Husayn in charge. Within a few years the Baro-Bhuyans—led by one Harup Narayan of the Brahmaputra valley—defeated, captured, and executed Daniyal, and the region lapsed into Bhuyan confederate rule. Emergence of the Koch power It was in this context that a number of independent Koch tribes were united under a leader named Hajo, who occupied Rangpur and Kamrup. The Koches, spreading towards the southern plains, were able to ally with other tribal groups. Among various factors, the shift from slash-and-burn cultivation to settled cultivation and the breakdown of tribal clan-based relations are given as factors that contributed to the growth of Koch power. As part of these alliances Hajo's daughter Hira married Hariya Mandal, a member of the Mech tribe from Chiknagram in