Causes for Magadha Supremacy
Earlier, the general impression among the historians was that if Buddhism as a religio-political system was a brainchild of the Buddha, the formation of the Magadhan empire as a new political phenomenon was entirely due to the military prowess, the able statesmanship and the shrewd diplomacy of the Magadhan kings like Bimbisara, Ajatashatru, Shisunaga and Mahapadmananda. However, current historians have added new dimensions to the process by which Magadha was able to become the first empire in ancient period, without divesting certain individuals off their roles.
The state of Magadha had all the prerequisites which are essential for the rise and growth of an empire. Its geographical position was an important factor. The mighty Ganga, Gandak and Ghaghra on the north and Son in the south served as means for defence as well as communication with upper India and the sea. The older capital city Rajagriha surrounded by five hills and fortified quite early with cyclopean outer walls twenty five miles in lengths, and the later and the more famous capital Fataliputra at the junction of the Ganga and the Son were both well protected against outside invasions. The enclosed area of Rajagriha had an excellent water supply, grazing grounds and surplus food both in agriculture and cattle products.
Natural resources were also favourable to Magadha. The soil was rich for cultivation. The river water could be used to irrigate the land if rainfall was not sufficient. The neighbouring dense forest provided both timber for houses and bridges and elephants for the army. The control of the areas of south Bihar (now Jharkhand) which had iron ores in abundance made Magadha the nerve centre of economic and political activities. The iron tools were used to clear the land systematically and to bring them under cultivation. Besides these, iron was used for making better and sturdier implements and weapons.