Himachal Pradesh has been inhabited by human beings since dawn of civilization. The earliest known inhabitants of the region were tribals called Dasas. Later, Aryans came and they assimilated in the tribes. In the later centuries, the hill chieftains accepted suzerainty of the Mauryan Empire, the Kaushans, the Guptas and Kanuaj rulers. During the Mughal period, the Rajas of the hill states made some mutually agreed arrangements which governed their relations.