Out of the sixteen Mahajanapadas, it was Magadha that expanded considerably under powerful rulers like Bimbisara, Ajatashatru and Mahapadmananda. The last king of the Nanda dynasty was defeated by Chandragupta Maurya in 322 BC. The Maurya Empire (322-185 BC) was a geographically extensive and powerful political and military empire in ancient India. It was the first empire to unify India into one state, and the largest on the Indian subcontinent.
The empire was established by Chandragupta Maurya in Magadha (in modern Bihar) when he overthrew the Nanda Dynasty. He went on to conquer the northwestern parts of the subcontinent that had been conquered by Alexander the Great.
Chandragupta was supported by a wise man named Chanakya or Kautilya. Many of Chanakya's ideas were written down in a book called the Arthashastra. Chandragupta ruled from 322 BC to 297 BC. He embraced Jainism under the influence of Bhadrabahu. He died at Sravanabelgola near Mysore.
Bindusara (297 BC-272 BC), the son and successor of Chandragupta Maurya, was also known as Mitraghata (slayer of enemies). He is said to have conquered Deccan, extending Mauryan control as far as Mysore. He also had contacts with Antiochus I, the Greek ruler of West Asia. It appears from the Buddhist literature that after the death of Bindusara, there was a struggle for the throne among his sons.
Ashoka emerged victorious in this fratricidal war of succession and ascended the throne of Magadha. The empire flourished under the reign of Chandragupta's grandson, Ashoka the Great. At its greatest extent, it stretched to the north to the natural boundaries of the Himalayas and to the east into what is now Assam. To the west, it reached beyond modern Pakistan, to the Hindu Kush mountains in what is now Afghanistan.
Ashoka ruled the Maurya Empire for 37 years from 268 BC until he died in 232 BC. During that time, Ashoka pursued an active foreign policy aimed at setting up a unified state. Ashoka became involved in a war with the state of Kalinga which is located on the western shore of the Bay of Bengal. However, he was so horrified when he saw the violence and bloodshed that he decided not to fight any more wars.
Ashoka embraced Buddhism and gave up war. He was a benevolent ruler and did many things for the welfare of his subjects. His policy of ‘dhamma’ was based on religious toleration, respect to elders, care for the old, kindness, truthfulness and purity. It was through his efforts that Buddhism spread beyond the boundaries of India. The rock edicts and pillar edicts inscribed by him give a detailed account of his reign.
Ashoka was the first ruler who tried to take his message to the people through inscriptions. Most of Ashoka’s inscriptions were in Prakrit and were written in the Brahmi script. The Arthashastra and the Edicts of Ashoka are the primary sources of written records of Mauryan times. The Lion Capital of Ashoka at Sarnath has been made the national emblem of India.
After Ashoka’s death, his empire disintegrated into pieces. There was also the danger of foreign invasion. The economic condition of the country deteriorated. The last king of the Maurya dynasty was Brihadratha.
Ashoka was followed for 50 years by a succession of weaker kings. Brihadrata, the last ruler of the Mauryan dynasty, held territories that had shrunk considerably from the time of emperor Ashoka. Brihadratha was assassinated in 185 BC by the Brahmin general Pushyamitra Sunga, commander-in-chief of his guard, who then took over the throne and established the Sunga dynasty.
In the north-west, and in parts of north India, kings known as the Indo-Greeks ruled for about one hundred years. They were followed by a Central Asian people known as the Shakas, who set up kingdoms in the north-west, north and western India. Some of these kingdoms lasted for about 500 years, till the Shakas were defeated by the Gupta kings. The Shakas in turn were followed by the Kushanas.
The Shakas who ruled over parts of western India fought several battles with the Satavahanas, who ruled over western and parts of central India. The Satavahana kingdom, which was established about 2100 years ago, lasted for about 400 years. Around 1700 years ago, a new ruling family, known as the Vakatakas, became powerful in central and western India.
In south India, the Cholas, Cheras and Pandyas ruled between 2200 and 1800 years ago. About 1500 years ago, there were two large kingdoms, those of the Pallavas and the Chalukyas.