(i) The period before the establishment of the Mauryan empire was a period of relatively rapid social and economic changes. There were small pieces of tribal politics, the development of the caste model and the move to the rice lands of the Eastern Gangetic valley.

(ii) In times of the disintegration of old social ties, during the establishment of new ways of being in social and political relationships, ideas based on great change was available. The emergence of Buddhism and Jainism was a result of this upheaval.

(iii) From their original settlements in the Punjab region, the Aryans gradually began to penetrate eastward, clearing dense forests and establishing tribal settlements along the Ganga and Yamuna plains between 1500 and CA 800 BC.

(iv) By around 500 BC, most of northern India was inhabited and had been brought under cultivation, facilitating the increasing knowledge of the use of iron implements, including ox-drawn ploughs, and spurred by the growing population that provided voluntary and forced labour.

(v) As river based and inland trade flourished, many towns along the Ganga became centers of trade, culture, and luxurious living.

(vi) Increasing population and surplus production provided the bases for the emergence of independent states with fluid territorial boundaries over which disputes frequently arose.

(vii) The basic administrative system headed by tribal chieftains was transformed by a number of regional republics or hereditary monarchies that devised ways to appropriate revenue and to conscript labour for expanding the areas of settlement and agriculture farther east and south, beyond the Narmada river.

(viii) These emergent states collected revenue through, officials, maintained armies, and built new cities and highways.

(ix) By 600 BC sixteen such territorial powers stretched across the North Indian plains from modern-day Afghanistan to Bangladesh.

(x) The right of a king to his throne was usually made lawful through elaborate sacrifice rituals and genealogies i.e. history of members of a family from past to present concocted by priests who ascribed to the king divine or superhuman origins.

(xi) A total of sixteen mahajanapadas emerged. Magadha, Kasi, Avanti, Vaishali and Lichhavi etc., were some of the important mahajanapadas.