 Some travelled westwards and established themselves as rulers of the Hurrian Mitanni kingdom by around 1500 BCE (see Indo-Aryan superstrate in Mitanni).Others travelled eastwards and inhabited the Gangetic basin while others travelled southwards and interacted with the Dravidian people.In books such as "The Myth of the Aryan Invasion of India" and "In Search of the Cradle of Civilization" (1995), Frawley criticises the 19th century racial interpretations of Indian prehistory, such as the theory of conflict between invading Caucasoid Aryans and Dravidians.