From 6th century BC onwards, we find widespread use of iron in eastern Uttar Pradesh and western Bihar, thus creating conditions for the creation of large territorial states. The new iron implements enabled the farmers to have surplus produce, some of which could be spared for taxes, thus enabling the kings to organize a state and a standing army. Some of these were Magadha, Koshala, Vatsa and Avanti.
The Magadhan Empire became prominent under Bimbisara, who was a contemporary of Buddha. He started the policy of conquest which ended with the Kalinga war of Ashoka. The earliest capital of Magadh was Rajgir, surrounded by five hills, making it virtually unassailable.
The Nandas were very rich and powerful. So great was their power that Alexander did not dare move towards them when he came to India. However, the later Nandas proved to be weak rulers and their reign was supplanted by the Mauryas under which the Magadhan empire reached its zenith.
The Maurya dynasty was founded by Chandragupta Maurya. He took advantage of the unpopularity of the later Nandas and with Chanakya’s help, overthrew the Nandas and set up his rule. Chandargupta was a powerful and able ruler. He liberated north-western India from Selucus and thus built a vast empire which excludes only today’s Kerala and Tamilnadu.
The Mauryas had an elaborate administrative machinery and Magasthenes’ Indica and Kautilya’s Arthshastra tell us a lot about it. Magasthenes was a Greek ambassador sent to the Mauryan court by Selucus of Greece. He lived in the Mauryan capital of Pataliputra. His writings describe the Mauryan society, economy and administration of those days. Even Arthshastra written by Kautilya (Chanakya) gives us valuable insights into statecraft and the society then. Chandargupta Maurya had a large army, a most distinguishing feature of his rule.
Chandargupta Maurya was succeeded by Bindusara, who in turn, was succeeded by Ashoka (273-232 BC), the greatest Mauryan ruler. After his accession in 261 BC, he fought only one major battle - the Kalinga War. The Kalinga War is found inscribed on the 13th Rock Edict (A royal order, and there are many by Ashoka addressed to his people and inscribed on rocks throughout his empire). The king was greatly moved by the sufferings of the people, and therefore, decided to give up war for ever. He converted to Buddhism thereafter and also sponsored the 3rd Buddhist Council where missionaries from distant lands had come.
Ashoka calls himself priyadasin in his inscriptions and was the first ruler to address his subjects directly. The language was Prakrit in the Brahmi script. Ashoka had a vast empire and he exercised strict control over it. He had appointed rajukas, or judicial officers to reward and punish, wherever appropriate.
The Mauryas had a vast bureaucracy. Important functionaries were called tirthas. Most of them were paid in cash. Pana was a term for silver coins during this time. Samharta was the officer for the assessment of taxes. Punch–marked silver coins (without the king’s or dynasty’s name) was the imperial currency.
However, the growing weakness of the Mauryas, especially after Ashoka, caused their decline and ultimate fall. The Maurya empire was finally destroyed by Pushyamitra Shunga in 185 BC.