Vajrayana or Tantrayana (the Tantric vehicle to enlightenment), which derives from Mahayana, is the school most closely associated with Tibetan Buddhism — so integral a part of it that it has become virtually identified with the religion of Tibet. The most mystical and esoteric of the schools, Tantric Buddhism is farthest from the common origin, and found little or no acceptance in southeast Asia, where it is sometimes not even considered an authentic school of Buddhism. The concepts and practices of tantrism originated in India and are associated with Shaivism, the cult of Shiva, the god of Yogins. It was from Indian sources that Mahayanists absorbed this movement, and these two schools are exemplified in the great Lo Monthang gompas: Mahayana in Thubchen, and Vajrayana in Jampa.
Vajrayana or Tantrayana Buddhism involves mystical concepts and practices, some of which appear to depart sharply from central Buddhist precepts.
The religious practices found in the Tibetan cultural world, accepted by and even conducted by the monastic orders, include the incantation of mystic, magical formulas, the exorcism and destruction of demons, divination, auguries, oracles, and symbolic sacrifice and ransom — aspects associated with Shamanism. It is this element within Tibetan Buddhism of magic and the supernatural, so remote from the original teachings and practices of Buddhism, that has led to its designation as Lamaism, as if it were a separate religion or at least a separate offshoot of the original faith. In attempting to account for these apparent contradictions, scholars have sought to identify the sources of these seeming divergences from what can be claimed as the pure, original Buddhist teachings.
Buddhism was a foreign import into Tibet, but Tibet made Buddhism its own, and that encompassing system of beliefs and practices known as Tibetan Buddhism can only be understood in the full context of the country, its history, its society, and its indigenous religious and cultural practices. It is also necessary to consider particular religious currents (i.e., Tantrism) within Buddhism that ultimately affected its form in Tibet.
Vajrayana Buddhism was established in Tibet in the 8th century when Śāntarakṣita was brought to Tibet from India at the instigation of the Dharma King Trisong Detsen, some time before 767. Tibetan Buddhism reflects the later stages of Indian tantric Buddhist developments, including the Yogini tantras, translated into the Tibetan language. It also includes native Tibetan developments, such as the tulku system, new sadhana texts, Tibetan scholastic works, Dzogchen literature and Terma literature. Vajrayana developed a large corpus of texts called the Buddhist Tantras, some of which can be traced to at least the 7th century CE but might be older.