Sultanganj is a place of hoary antiquity

Sultanganj is a place of hoary antiquity. It is traditionally associated with the sage Jahnu, whose ashram was a centre of learning and culture. Jahnu Muni's ashram was located on the rock jutting out of the bed of the Ganga River. Now the site has the Shiva temple of Ajgaivinath, also known as Gaibinath Mahadeo. The story is that the river Ganga on her way to the ocean interrupted the Muni in hismeditation by the rush of her currents. The sage swallowed the river in a gulp. Bhagiratha intervened and the Muni again let her out by making an incision in his thigh. That is why the river Ganga is also called Jahnavi.
Traditionally Sultanganj formed a part of the great Anga, State. In the days of the Mahabharata, Karna, the sixth brother of the five Pandavas, ruled in Anga. The capital of Anga was Champa. Champa is the present Champanagar situated three miles to the west of Bhagalpur. King Karna had his castles at Champa (modern Champanagar) and Jahnugiri (modern Sultanganj). At present Champanagar, the- site of Karna''s castle, is well known as Karnagarh. Karnagarh is practically a part of Bhagalpur town now.