Between the sixth and the fourth centuries BC Magadha became the most powerful Mahajanapda. Modern historians explain this development in a variety of ways: Magadha was a region where agriculture was especially productive. Besides iron mines were accessible and provided resources for tools and weapons. Elephants an important component of the army was found in forests in the region. Also the Ganga and its tributaries provided a means of cheap and convenient communication. However early Buddhist and Jaina writers who wrote about Magdha attributed its power to the policies of individual's ruthlessly ambitious kings of whom Bimbisara, Ajatshastru and Mahapadma Nanda are the best known and their ministers who helped implement their policies. Initially Rajagaha was the capital of Magadha.

The old name means house of the king. Rajagaha was a fortified settlement located amongst hills later in the fourth century BC the capital was shifted to Patliputra commanding routes of communication along the Ganga.