In the 6th century B.C., India comprised several Mahajanapadas or great states. While Kashi was initially a powerful kingdom, it was eventually incorporated into Kosala. Magadha, located in the fertile Gangetic plain and possessing rich iron ore deposits, began its ascent to power under rulers like Bimbisara in the 6th century B.C. It gradually surpassed other Mahajanapadas like Kashi and Kosala and eventually became the dominant power in northern India, forming the base for the later Mauryan Empire. By the close of the 6th century BC and early 5th century BC, Magadha was clearly emerging as the most significant power.