Padmasambhava 

The great 8th century ce yogin, often known as Guru Rinpoche, who was instrumental in introducing Buddhism into Tibet during the reign of King Trisong Detsen (Tibetan, Khri srong lde brtsan). He is especially venerated by the Nyingma school who view him as a ‘second Buddha’. He is said to have been born in Oḍḍiyāna and travelled widely throughout India prior to visiting Tibet. His name means ‘Lotus-born’ and derives from a legend that he was born in a lotus blossom on the river Indus. During his relatively brief stay in Tibet, it was his task to subdue the native gods and spirits who were hostile to the introduction of Buddhism and the construction of the monastery at Samyé (c.767). In this role, Padmasambhava became especially associated with the teachings and practices of Vajrakīla. Many legends have been handed down about the events of his life such as his involvement with the Indian princess Mandarāvā and the Tibetan noble woman Yeshé Tshogyel who became his chief Tibetan disciple. The twelve most important events of his life are remembered and celebrated in turn on the tenth day of each month by followers of the Nyingma school. He is also supposed to have buried secret treatises (terma) in the earth which are periodically rediscovered from time to time.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)