Tibetan Religion. The oldest form of religion in Tibet is Bon, which seems to have been shamanistic. It still exists, but synthesized with Buddhism, which came to Tibet gradually from c. the 7th to the 11th c. CE., so that it now appears more as a Buddhist sect than as what originally it had been. Buddhism in Tibet, having come to it through Indian masters, may be said to be more like the Buddhism that had developed in the first millennium or so after its first appearance in India than it is like any of the Mahayana developments in China, Korea, and Japan. Nevertheless, some of the latter type of influence has affected Tibetan Buddhism, which is represented by four principal sects or traditions: Kagyu, Sakya, Nyingma, and Gelug.

Geddes MacGregor, Dictionary of Religion and Philosophy, New York: Paragon House, 1989