600 b.c. to around 700 a.d.
While both the reforming sects became popular a majority of the population clung to Hinduism. Saivism and Vaishnavism developed around 200 B.C. There were many significant developments up to 3rd century a.d., the most significant being the code of Manu. A number of Puranas were written. The religion of the Upanishads was made simple and easy to understand. The famous literature of this age include Patanjali’s Mahabhasya and Bharata’s Natyasastra.
The Epics became the very popular during this period. One of the significant developments in the advance of the religious thought was the doctrine of Avatara and the concept of Sakti personified as the Mother Goddess. Saktism gave rise to religious literature known as Tantras. This period saw the compilation of the eighteen Puranas, the dramas of Bhasa and Kalidasa, mathematical treatise of Aryabhatta, astronomical treatise of Varahamitra.
About the middle of the seventh century Buddhism was in a state of decline. At this time the country was divided into a number of small sects, some who went blindly by the scriptures while the others were ready to destroy all that was sacred. Fanatic, religion began to used as a weapon of aggression rather than at finding the Supreme Reality. This was brought about by the uncultured and uneducated people who had embraced Buddhism without understanding the teachings of Buddha. India was going through spiritual, intellectual, social turmoil. Squabbles, dissension’s and corruption prevailed in the name of religion.