The Present Assam was referred to as Kamrup in many of the ancient Indian literature. It was also known as Pragjyotishpur due to the astrology (Jyotish Shashtra) practices that prevailed in this part of the country during that time. However, "Kamrup" became a more predominant name in the later part of the history. There is a famous story which says the reason behind the naming of this place "Kamrup":
Lord "Shiva" married Parvati, the daughter of Daksha, a very powerful king of that time. The King however, did not like his son-in-law for some reasons and hence did not invite him for the "Jagna" (the great sacrifice) ceremony which the king organised in a great fashion. Parvati being the daughter of the king could not resist from attending the ceremony and went there with the permission from her husband. As she reached the auspicious venue, "Daksha" did pass on derogatory comments on her husband and that too in front of a huge gathering. She became very annoyed and got disgusted at the discourtesy shown to her husband and sacrificed her life on the spot itself.
Overcome with grief at the death of Sati (Parvati), Shiva began a grim penance and wandered about the world carrying her dead body on his head. Shiva's 'dance of death' and penance alarmed all the gods because it threatened to destroy the world. In order to stop the frightful wanderings of Shiva, the supreme god, Vishnu, cut the dead body of Sati into fifty- one pieces with his great weapon, the "Shudarshan Chakra" (Discus). The pieces fell onto the earth in fifty one different places and wherever they fell, the ground was held to be sacred. One of the important organs of Sati fell on Nilachal hill in Guwahati and the place was thenceforth held sacred and it says that the famous Kamakhya Temple was originated from that "Sati's" organ only.
The famous Kamakhya Temple
As Shiva continued to do penance, the other gods became afraid that he would thereby acquire universal power. They sent Kamadeva, the God of Love, to make Shiva fall in love again, and thereby break his penance. Kamdeva succeeded in his mission, but Shiva was so enraged at the result that he burnt Kamadeva into ashes by a fiery glance of his third eye. Kamadeva eventually regained his life and his original 'form' (Rupa) in Assam and the land where this took place become known as "Kamrup" ("Kamarupa").