Wikipedia
Kāmarūpa (; also called Pragjyotisha), was one of the historical kingdoms of Assam alongside Davaka, that existed from 350 to 1140 CE. Ruled by three dynasties from their capitals in present-day Guwahati, North Guwahati and Tezpur, it at its height covered the entire Brahmaputra Valley, North Bengal, Bhutan and parts of Bangladesh, and at times portions of West Bengal and Bihar.
Though the historical kingdom disappeared by 12th century to be replaced by smaller political entities, the notion of Kamarupa persisted and ancient and medieval chroniclers continued to call this region by this name. Coins of Alauddin Hussain Shah, who invaded the Kamata Kingdom in the late 15th century, called the region Kamru or Kamrud. In the 16th century the Ahom kingdom came into prominence and assumed for itself the political and territorial legacy of the Kamarupa kingdom.
The name of this kingdom survives in Kamrup, a present-day district in Assam.