Conditions for the Rise of Large States(Magadha):
From the sixth century BC onwards, the increasing use of iron in eastern UP and western Bihar created conditions for the formation of large territorial states.
Armed with iron weapons, the warrior class now played an important role. The new agricultural tools and implements enabled the peasants to produce far more food grains than they required for consumption.
The extra produce could be collected by the princess to meet their military and administrative needs.
The surplus could also be made available to the towns that had sprung up in fifth century BC. These material advantages naturally enabled the people to remain on their land, and also to expand at the cost of the neighbouring areas. The rise of large states with towns as their base of operations strengthened the territorial idea. People owed strong allegiance to the janapada or the territory to which they belonged rather than to their jana or tribe.
A few janapadas arose towards the end of the Vedic- period. However, with progress in agriculture and settlement by 500 BC, they became a common feature. Around 450 BC, over forty janapadas covering even Afghanistan and south-eastern Central Asia are mentioned by Panini. However, the major part of southern India was excluded. The Pali texts show that the janapadas grew into mahajanapadas, that is large states or countries. These texts mention sixteen of them. Nine of them also occur in Panini not as mahajanapadas but as janapadas.
In the age of the Buddha we find sixteen large states called mahajanapadas. Most of these states arose in the upper and mid-Gangetic plains, including the doab area covered by the Ganges, Yamuna, and their tributaries. They were mostly situated north of the Vindhyas and extended from the north-west frontier to Bihar.
Of these, Magadha, Koshala, Vatsa, and Avanti seem to have been powerful. Beginning from the east, we hear of the kingdom of Anga which covered the modern districts of Monghyr and Bhagalpur. It had its capital at Champa, which shows signs of habitation in the fifth century BC, and there is a mud fort dating to that century. Eventually the kingdom of Anga was swallowed by its powerful neighbour Magadha.
Magadha embraced the former districts of Patna, Gaya, and parts of Shahabad, and grew to be the leading state of the time. Its earlier capital was Rajgir, and later Pataliputra. Both were fortified, and show signs of habitation around the fifth century BC. North of the Ganges, in Tirhut division lay the state of the Vajjis which included eight clans.
However, the most powerful dynasty was that of the Lichchhavis with their capital at Vaishali which is coterminous with the village of Basarh in Vaishali district. The Puranas push the antiquity of Vaishali to a much earlier period, but archaeologically Basarh was not settled until the sixth century BC.
Further west we find the kingdom of Kashi with its capital at Varanasi. Excavations at Rajghat show that the earliest habitations started around 500 BC, and the city was enclosed by mud embankments at about the same time. Initially Kashi appears to have been the most powerful of the states, but eventually it succumbed to the power of Koshala. Koshala embraced the area occupied by eastern UP and had its capital at Shravasti, which is coterminous with Sahet-Mahet on the borders of Gonda and Bahraich districts of UP. Diggings indicate that Sahet-Mahet was barely settled in the sixth century BC, but we see the beginnings of a mud fort. Koshala had an important city called Ayodhya which is associated with the story in the Ramayana.
Excavations however show that it was not settled on any scale before the fifth century bc. Koshala also included the tribal republican territory of the Shakyas of Kapilavastu. The capital of Kapilavastu is identified with Piprahwa in Basti district. Habitation at Piprahwa did not occur earlier than c. 500 BC. Lumbini, which is situated at a distance of 15 km from Piprahwa in Nepal, served as another capital of the Shakyas. In an Ashokan inscription, it is called the birthplace of Gautama Buddha.
In the neighbourhood of Koshala lay the republican clan of the Mallas, whose territory touched the northern border of Vajji state. One of the capitals of the Mallas was at Kushinara where Gautama Buddha passed away. Kushinara is coterminous with Kasia in Deoria district. Further west was the kingdom of the Vatsas, along the bank of the Yamuna, with its capital at Kaushambi near Allahabad. The Vatsas were a Kuru clan who had shifted from Hastinapur and settled at Kaushambi. Kaushambi was chosen because of its location near the confluence of the Ganga and the Yamuna. In the fifth century BC, it had a mud fortification, as excavations reveal.
We also hear of the older states of the Kurus and the Panchalas which were situated in western UP, but they no longer enjoyed the political significance they had attained in the later Vedic period. In central Malwa and the adjoining parts of MP lay the state of Avanti. It was divided into two parts, the northern part with its capital at Ujjain, and the southern part at Mahishamati. Both these towns became fairly important from the fifth century BC onwards, though eventually Ujjain surpassed Mahishamati. It developed large-scale working in iron and erected strong fortifications.
The political history of India from the sixth century BC onwards was one of struggles among these states for supremacy. Eventually the kingdom of Magadha emerged as the most powerful and founded an empire. In the north-west, Gandhara and Kamboja were important mahajanapadas. Kamboja is called a janapada in Panini and a mahajanapada in the Pali texts.
It was located in Central Asia in the Pamir area which largely covered modern Tajikistan. In Tajikistan, the remains ofa horse, chariots and spoked wheels, cremation, and svastika, which are associated with the Indo-Aryan speakers dating to between 1500 and 1000 BC, have been found. Around 500 BC, both Sanskrit and Pali were spoken in Kamboja, which was connected with Pataliputra by the uttarapatha.