Vedic literature called the Vedas written in the ancient Sanskrit language evolved at this time along with the epic literature Ramayana and Mahabharata. Period of Aryan invasion (?): Since the 18th century and from the time of the British rule historians have considered this period to be the time of Aryan invasion (?). Aryans is said to have invaded from Central Asia and the Russian steppes and supplanted the Indus civilization and later intermingled with the locals. This theory has been questioned recently since nowhere in the ancient Indian texts is there a mention of an Aryan invasion.