The Magadha Empire was founded when the four Mahajanapadas – Magadha, Kosala, Vatsa, and Avanti – were engaged in a struggle for domination from the 6th century BC to the 4th century BC. Magadha has drawn the attention of historians for the last two hundred years because it had become the nucleus of the political power of the well-known Mauryan dynasty. The Magadhan kingdom began to grow during the sixth century BCE itself. However, this process accelerated considerably under the Nandas and the Mauryas. The location of Ashokan inscriptions indicates that a major part of the Indian sub-continent, excluding the eastern and southern, was under Magadhan rule. The period of Mahajanpadas (600 BCE) is also known as the Period of 2nd urbanization (IVC was the 1st urbanization) as the center of polity and economy shifted from India’s North-west to Eastern states (mainly Bihar). Urban settlement and the use of Iron tools enabled the formation of large territories called Mahajanapadas.
The events and traditions of the middle Ganga plains where Magadha was prominently located are well-preserved in the early Buddhist and Jaina literature. Some of the texts of the Buddhist tradition are compiled as the Tripitikas and the Jatakas. Those pertaining to the early Jaina tradition are the Acharanga Sutra and Sutrakritanga, which are considered earlier than the others. All these were, however, written or compiled well after the sixth century BCE at different times. For particularly the early events of a political nature, Buddhist and Jaina traditions present them more authentically and directly than do the later Brahmanical accounts of the various Puranas, which attempt to provide histories of royal dynasties to the period of the Guptas. Later Buddhist chronicles like the Mahavamsa and Dipavamsa, compiled in Sri Lanka, are significant sources for the events related particularly to Ashoka Maurya’s reign.
These, along with the Divyavadana (which is preserved outside India in the Tibetan and Chinese Buddhist sources) not being contemporary to the period under discussion, have to be used cautiously as they developed in the context of Buddhism’s spread outside India. Foreign sources of information, which are considerably more relevant and are near-contemporary, are accounts gathered from Classical writings in Greek and Latin. These are impressions of travelers who visited India around that time, and the name of Megasthenes, who visited the court of Chandragupta Maurya, is famous in this respect. Megasthenes is, however, known to us only through quotations in later Greek writings of Strabo and Diodorus of the first century BCE, and Arrian of the second century CE. Since north-west India from about the sixth century BCE till about the fourth century BCE was under the sphere of foreign rule, some of the information on the phase of Achaemenian (Persian) rule and later, on the invasion of Alexander, comes to us from the Persian inscriptions and Greek sources like Herodotus’ account. The mahajanapadas were located over a major part of the Ganga valley with a few to the north-west and south-west. However, of the four most powerful kingdoms, three – Kosala, the Vajji confederacy, and Magadha – lay in the middle Ganga valley and the fourth, Avanti, was in western Malwa. The kingdoms that surrounded Magadha were Anga in the east, the Vajji Confederacy to the north, to its immediate west the kingdom of Kashi and further west, the kingdom of Kosala.
Magadha can be identified with the modern districts of Patna, Gaya, Nalanda, and parts of Shahabad in the present-day state of Bihar. Geographically, Magadha’s location had large tracts of alluvial soil in its vicinity. The soil could be easily cleared off the heavy overgrowth with the use of iron implements and proved extremely fertile. Various varieties of paddy were grown, as mentioned in the early Buddhist texts. This enabled farmers to produce a considerable surplus, which augmented taxes.
Magadha also had access to an easy supply of elephants. In fact, Magadha was one of the few kingdoms that used elephants on a large scale in wars, giving it an edge over others. The elephants could be procured from the east. Nandas, according to Greek sources, maintained 6000 elephants. Elephants had an advantage over horses and chariots because they could be used to march across marshy lands and areas with no roads or other means of transport. R. S. Sharma believes that the unorthodox character of the societal set-up in Magadha allowed it to become more receptive to expansionist policies of its rulers. Magadha had a happy admixture of Vedic and non-Vedic people, who were different in their outlook than those of orthodox Vedic societies.
Interestingly, the earliest capital of Magadha, Rajagriha (Girivraja), was situated to the south of the river and not near it. Rajagriha was surrounded by five hills and proved to be impregnable. It not only enjoyed a strategic location, but also lay in the vicinity of iron-encrusted outcrops. It has also been suggested that its accessibility to copper as well as to the forests of the present-day southern Bihar region can effectively explain why early Magadhan kings did not choose to have their capital in the most fertile plains of the Ganges valley but in a comparatively isolated region. The capital of Magadha did, however, shift to Pataliputra (originally Pataligramma) situated on the confluence of several rivers like the Ganga, Gandak, Son, and Poon Pun. The rivers could be used as communication routes by the army moving in the direction of north, west, south, and east. Besides, being surrounded by rivers made its position impregnable, functioning as a veritable water fort (jaladurga). Pataliputra became the capital of Magadha under the Mauryas. This enabled Magadha to effectively command the Uttarapatha (northern route), which lay to the north of the river Ganges, along the foothills of the Himalayas. The river also came to be used as one of the main arteries connecting Magadha with different regions, making heavy transport along the river possible. Thus, Magadha had certain natural advantages over other contemporaneous kingdoms, though some, like Avanti to its south-west, Kosala to its north-west, and the Vaiji Confederacy to its north, were equally powerful at the turn of the sixth century BCE.
Recent research has suggested that accessibility to iron mining areas in particular enabled kingdoms like Magadha and Avanti to not only produce good weapons of warfare but also in other ways. It facilitated the expansion of agrarian economy and thereby, the generation of substantial surplus, extracted by the state in the form of taxes. This in turn enabled them to expand and develop their territorial base. Avanti, it must be noted, became a serious competitor of Magadha for quite some time, and was also located not far from the iron mines in eastern Madhya Pradesh. Avanti had defeated the Vatsas of Kaushambi and planned to invade Magadha. Ajatshatru, in response to this threat, began the fortification of Rajgir, the remains of which can still be seen. The invasion, though, did not take place. Magadha was located in a region which had an abundance of timber. Megasthenes has remarked about the wooden walls and houses of Magadha. Remains of wooden palisades of the 6th century BCE have been discovered to the south of Patna. Timber could be easily used to manufacture boats through which the Magadhan army could advance towards the east and the west.