Kinnaur’s ancient history is shrouded in myth and sparse in fact. Between the 6th century BC and the 6th century AD, the land came under the sway of the Mauryas, Kushanas and Guptas. Local authority, however, often rested with indigenous rulers. It was the Thakur of Kamru who founded the Bushahr state in the 7th-8th centuries AD. Though the region witnessed many battles for supremacy, the rule of the Bushahr was strong enough to withstand Mughal assaults in medieval times. Of the Bushahr rulers, Raja Kehri Singh was, reputedly, the most valiant, while Raja Ram Singh established his capital at Rampur. In the early 19th century, Bushahr capitulated to Gurkha invasions; and it was Ranjit Singh and the British in turn who fought off the intruders. The region consequently came under the influence of the Sikhs and then the British.
Except for a revolt in 1857, when Raja Shamsher Singh of Bushahr was part of an alliance of princes against the East India Company, the region, known as Chini tehsil from the late 19th century, remained under British suzerainty until 1947. With Independence, the tehsil became part of Mahasu district, until 1 May 1960, when a reorganisation of borders created what is presently Kinnaur district.