赤松德贊
The murder of Rapalchen by his brother Lang darma in 838 ended the imperial patronage of Tibetan Buddhism and its Nyingma school, which had begun about eighty years earlier around 755 with Padmasambhava, Shantirakshita and Trisong Detsen. Afterwards, Lang darma proceeded to nearly destroy Buddhism in Tibet, together with the 13 Nyingma monasteries, and their ordained monastics, which were built during the reign of Trisong Detsen.