During the reign of King Bimbisara of the Haryanka dynasty of Magadha pursued an expansionist policy.
[2][3] During the early years of the reign of Ajatashatru, Avanti managed to establish its supremacy by invading certain parts of Magadhan territories.
[4] After the death of Ajatashatru a period of uncertainty followed and a succession of weak rulers again gave rise to a threat of a Pradyota invasion.
Enraged by this, the people of Magadha overthrew the last of the Haryanka rulers and one of the ministers, Shishunaga, usurped the throne.
Shishunaga defeated the Pradyota dynasty of Avanti, removing a major threat to the Magadhan Empire.