In ancient times the tract which corresponds to the district of Ranchi
and the neighbouring parganas was in the undisturbed possession of Munda and Oraon tribes
and was known to Aryans as Jharkhand or the 'forest territory'. The entire tract was
presumably beyond the pale of the direct Hindu influence in ancient India. However,
Jarasandh, the mighty emperor of Rajgriha in the Mahabharat period might have exercised
some kind of loose supervision over the area. Similarly, Mahapadmanand Agrasen of Magadh,
who subdued the entire country upto Orrisa, might have gained some control over Jharkhand as well .
Possibly, the area was included in the Magadh Empire during the reign of Ashoka ( 273-232 B.C. ). With the decline of Mauryan power, King Kharavels of Kalinga led on army through Jharkhand and ransacked Rajgriha and Patliputra. Later , Samudra Gupta (335-380 A.D.) must have passed through the area on his expedition to the Deccan.
The Chotanagpur Raj is believed to have been set up in fifth century A.D. after the fall of the imperial Guptas. Phanimukut was elected the first king It is said that he was found by the Side of a tank under the protection of a Nag ( Snake). Hence the dynasty founded by him was named the Nag Dynasty.