Who founded shamanism?

The earliest knowledge regarding Shamanism comes from Russian anthropologists when they studied tribal nomadic herders in Siberia in the 19th century. Their detailed descriptions of the spiritual practitioners the tribesmen called Shamans, led to the term being continued by anthropologists and historians.

A wonderful book detailing the origins of this, and other primitive practises, is Dawn Behind the Dawn: A Search for the Earthly Paradise, by Geoffrey Ashe.