Kamarupa (Historical Kingdom)
Kamarupa (Assamese: কামৰূপ ৰাজ্য), also called Pragjyotisha, was the first historical kingdom in Assam that existed between 350 and 1140 CE i.e. for almost 800 years. Ruled by three dynasties from their capitals in present-day Guwahati and Tezpur, it covered the entire Brahmaputra river valley, North Bengal and parts of Bangladesh.
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.
Read more about Kamarupa (Historical Kingdom): Sources For Kamarupa, Boundaries, Kamarupa State, Political History