Amongst the sixteen Mahajanapadas, the kingdom of Magadha rose to prominence under a number of dynasties that peaked in power under the reign of Asoka Maurya, one of India's most legendary and famous emperors. The kingdom of Magadha had emerged as a major power following the subjugation of two neighbouring kingdoms, and possessed an unparalleled military.

Haryanka dynasty: According to tradition, the Haryanka dynasty founded the Magadha Empire in 684 BC, whose capital was Rajagriha, later Pataliputra, near the present day Patna. This dynasty was succeeded by the Shishunaga dynasty.

Shishunaga dynasty :This period saw the development of two of India's major religions. Gautama Buddha in the 6th or 5th century BC was the founder of Buddhism, which later spread to East Asia and South-East Asia, while Mahavira founded Jainism. This dynasty lasted till 424 BC, when it was overthrown by the Nanda dynasty.

Nanda dynasty

The Nanda dynasty was established by an illegitimate son of the king Mahanandin of the previous Shishunaga dynasty. Mahapadma Nanda died at the age of 88, ruling the bulk of this 100-year dynasty. The Nandas were followed by the Maurya dynasty. It is said that rumors of the huge size of the Nanda army was in part responsible for the retreat of Alexander from India.

Maurya dynasty : In 321 BC, exiled general Chandragupta Maurya, under direct patronage of the genius of Chanakya, founded the Maurya dynasty after overthrowing the reigning king Dhana Nanda to establish the Maurya Empire. During that time, most of the subcontinent was united under a single government for the first time. Capitalising on the destabilization of northern India by the Persian and Greek incursions, the Mauryan empire under Chandragupta would not only conquer most of the Indian subcontinent, but also push its boundaries into Persia and Central Asia, conquering the Gandhara region. Chandragupta Maurya was influenced by the jainacharya Bhadrabahu and he adopted Jainism.He is credited for the spread of Jainism in southern Indian region. Chandragupta was succeeded by his son Bindusara, who expanded the kingdom over most of present day India, barring Kalinga, and the extreme south and east, which may have held tributary status. Modern day India is an image of the Mauryana, that tied all the peoples and cultures of the erstwhile separate kingdoms under one banner, and predicted a common destiny for all Indians (then mainly Hindus and Buddhists). The tradition was continued later by the Mughals and the British, who formed similar empires.

Bindusara's kingdom was inherited by his son Ashoka The Great who initially sought to expand his kingdom. In the aftermath of the carnage caused in the invasion of Kalinga, he renounced bloodshed and pursued a policy of non-violence or ahimsa after converting to Buddhism. The Edicts of Ashoka are the oldest preserved historical documents of India, and from Ashoka's time, approximate dating of dynasties becomes possible. The Mauryan dynasty under Ashoka was responsible for the proliferation of Buddhist ideals across the whole of East Asia and South-East Asia, fundamentally altering the history and development of Asia as a whole. Ashoka the Great has been described as one of the greatest rulers the world has seen. Ashoka's grandson Samprati adopted Jainism.He was influenced by the teachings of a great jain acharya Arya Suhasti. Following the lines of Ashoka, Samprati spread Jainism in many parts of this world and Indian sub-continent.It is said that Samprati built 1,25,000 Jain Temples all over India, many of which are worshipped today as well.

Sunga dynasty : The Sunga dynasty was established in 185 BC, about fifty years after Ashoka's death, when the king Brihadratha, the last of the Mauryan rulers, was brutally murdered by the then commander-in-chief of the Mauryan armed forces, Pusyamitra Sunga, while he was taking the Guard of Honour of his forces. Pusyamitra Sunga then ascended the throne.

Kanva dynasty : The Kanva dynasty replaced the Sunga dynasty, and ruled in the eastern part of India from 71 BC to 26 BC. The last ruler of the Sunga dynasty was overthrown by Vasudeva of the Kanva dynasty in 75 BC. The Kanva ruler allowed the kings of the Sunga dynasty to continue to rule in obscurity in a corner of their former dominions. Magadha was ruled by four Kanva rulers. In 30 BC, the southern power swept away both the Kanvas and Sungas and the province of Eastern Malwa was absorbed within the dominions of the conqueror. Following the collapse of the Kanva dynasty, the Satavahana dynasty of the Andhra kindgom replaced the Magandhan kingdom as the most powerful Indian state.

The term "Janapada" literally means the foothold of a tribe. The fact that Janapada is derived from Jana points to an early stage of land-taking by the Jana tribe for a settled way of life. This process of first settlement on land had completed its final stage prior to the times of Buddha and Panini. The Pre-Buddhist North-west region of Indian sub-continent was divided into several Janapadas demarcated from each other by boundaries. In Panini, Janapada stands for country and Janapadin for its citizenry. These Janapadas were named after the tribes or the Janas who had settled in them. By circa 600 BCE, many of these Janapadas had further evolved into larger political entities by the process of land-grabbing which eventually led to the formation of kingdoms known in Buddhist traditions as the Mahajanapadas or the great nations (Sanskrit: Maha = great, Janapada = country).

The Buddhist and other texts only incidentally refer to sixteen great nations (Solasa Mahajanapadas) which were in existence before the time of Buddha. They do not give any connected history except in the case of Magadha. The Buddhist Anguttara Nikaya, at several places, gives a list of sixteen nations:

Kasi, Kosala, Anga, Magadha, Vajji (or Vriji), Malla, Chedi, Vatsa (or Vamsa), Kuru, Panchala, Machcha (or Matsya), Surasena, Assaka, Avanti, Gandhara, Kamboja

The Jaina Bhagvati Sutra gives slightly different list of sixteen Mahajanapadas viz: Anga, Banga (Vanga), Magadha, Malaya, Malavaka, Accha, Vaccha, Kochcha (Kachcha?), Padha, Ladha (Lata), Bajji (Vajji), Moli (Malla), Kasi, Kosala, Avaha and Sambhuttara. Obviously, the author of Bhagvati has a focus on the countries of Madhydesa and of far east and south only. He omits the nations from Uttarapatha like the Kamboja and Gandhara. The more extended horizon of the Bhagvati and the omission of all countries from Uttarapatha clearly shows that the Bhagvati list is of later origin and therefore less reliable (Political History of Ancient India, 1996, p 86; History & Culture of Indian People, Age of Imperial Unity, p 15-16).

The main idea in the minds of those who drew up the Janapada lists was basically more tribal than geographical, since the lists include names of the people and not the countries. As the Buddhist and Jaina texts only casually refer to the Mahajanapadas with no details on history, the following few isolated facts, at best, are gleaned from them and other ancient texts about these ancient nations.