Magadha that corresponds roughly to the present Patna and Gaya districts, occupies an important place in the early history of India. The state of Magadha is birthplace of the development of two great religions Buddhism and Jainism. The state of Magadha produced learned scholars like Kautilya, Panini and Patanjali. The existence of the famous universities of Nalanda and Vikrama sila also contributed to the greatness of Magadha. King Vasu of Kum dynasty had conquered Magadha and incorporated it into his empire. After his death, his five sons divided his empire into five portions. Of these five sons, Brihadrath became the independent ruler of Magadha and is said to be the founder of Magadha Empire as well. His capital was `Girivraj`. The most ambitious and mighty ruler of `Brihadrath vamsa` was Jarasandha. He conquered many Kshatriya kings. With the help of Ipandavas, Lord Krishna, killed Jarasandha.
The decline of Magadha started after Jarasandha. Ripunjaya was the last king of this dynasty but his minister Pulika killed him and ascended the throne. Pulika had two sons, namely Balaka, and Pradotya. Pulika made Pradotya the ruler of Avanti and Balak became the ruler of Magadha. After some time a Samanta named Pulak killed Balaka and made his son Bimbisara, the ruler of Magadha. Bimbisara became the king of Magadha in 603 B.C. at the age of 15 and from this time the rise of Magadha started. Dr. Ray Choudhry observes, "The early dynastic history .of Magadha is shrouded is darkness. We have occasional glimpses of warlords and statesmen, some probably entirely mythical, other having mere appearance of a leader. The history commences with the famous Bimbisara of Haryanka Kula."