Lhalung Palgyi Dorje (Standard Tibetan: ལྷ་ལུང་དཔལ་གྱི་རྡོ་རྗེ། Wylie: lha lung dpal gyi rdo rje) was a Tibetan Buddhist monk who assassinated the Tibetan Emperor Langdarma in 842 CE. Palgyi Dorje was Padmasambhava's student. According to Tibetan tradition, King Langdarma persecuted Buddhism in Tibet. To end this persecution, Pelgyi Dorje traveled to the King's palace, where he surprised the King and killed him with a bow and arrow. Escaping by turning his black cloak inside out to show its white lining and riding his white horse into the river to wash off the charcoal with which he had made it appear black, he then fled to Amdo (Qinghai) or Yerpa, where he lived out the rest of his life as a recluse.