Channelling is the process through which a medium communicates information from spirits and other non physical beings, such as angels, deities or guardian spirits by entering into a trance or some other altered state od consciousness...
The urge to communicate with the spirit world is as old as humankind itself. in primitive cultures certain individuals, preists, shamans, or medicine people, would seek out the wisdom of the spirit world...
The ancient egyptians and romans as well as the early chinese, babylonians, tibetans, assyrians and celts, all channelled spirits and entities, and holy men and women of judaism, christianity and islam received divine guidance...
Divination and healing are forms of channelling, as is possession, when an entity seizes control of an individual, in the middle ages possession was seen as demonic rather than divine...
In the 19th and 20th centuries, when spiritualism was at its height, channelling grew in popularity....