The 'Great Vehicle' form that originated in Tibet

The Mahayana form developed out of the original Theravada form (it is at least 500 years younger) and originated in Tibet, where the Indian form of Buddhism mingled with the pre-existing shamanic 'Bon' religion to produce a somewhat esoteric hybrid with a huge pantheon of divine and semi-divine entities, each having guardianship over a particular area of human activity.