The main sources of information about this civilization are the Vedic texts which were compiled after the age of the Rig Veda. These were the Sam Veda Samhita, the Yajur Veda Samhita, Atharva Veda Samhita, Brahmanas and Upanishads. All these later Vedic texts were compiled in the upper Gangetic basin in 1000-500 BC. These texts show that the Aryans during the later Vedic period shifted from the North-West to the region of the Ganges and Yamuna. The whole of North India to Central India upto the river Narmada along with some regions south of the river comprised of Aryan influence. Archaeologists have excavated a site Hastinapur which belongs to this period between 1000 and 700 BC. The only available remains found are shreds of painted grey pottery, a few copper implements and traces of houses made of unbaked bricks.
New beliefs were born among the Aryans who started believing in the attainment of Nirvana through Gyan or the knowledge. The Upanishads criticized the rituals and laid stress on the value of right belief and knowledge. The conception of the material world as Maya or illusion also gained currency during this later Vedic age. Thus the tenets of Hinduism - Moksha, Karma and Maya were enunciated by the seers of the later Vedic period.