Wikipedia
Padmasambhava (lit. "Lotus-Born"), also known as Guru Rinpoche, was an 8th-century Indian Buddhist master. Although there was a historical Padmasambhava, nothing is known of him apart from helping the construction of the first Buddhist monastery in Tibet at Samye, at the behest of Trisong Detsen, and shortly thereafter leaving Tibet due to court intrigues.
A number of legends have grown around Padmasambhava's life and deeds, and he is widely venerated as a 'second Buddha' across Tibet, Nepal, Bhutan, and the Himalayan states of India.
In Tibetan Buddhism, he is a character of a genera of literature called terma, an emanation of Amitābha that is said to appear to tertöns in visionary encounters and a focus of guru yoga practice, particularly in the Rimé schools. The Nyingma school considers Padmasambhava to be a founder of their tradition.