abstract:Trisong Detsän or Trisong Detsen ཁྲི་སྲོང་ལྡེ་བཙན (Tibetan Wylie: khri srong lde btsan ; PRC: Chisong Dêzain; THDL: Trisong Detsen; other transcriptions: Trisong Detsan, Thrisong Detsän; traditional Chinese: 赤松德贊; simplified Chinese: 赤松德赞; pinyin: Chìsōng Dézàn; Thi-srong-detsan), was the son of Me Agtsom and one of the emperors of Tibet and ruled from 755 until 797 or 804 CE. Trisong Detsen was the second of the Three Dharma Kings of Tibet, playing a pivotal role in the introduction of Buddhism to Tibet and the establishment of the Nyingma, or 'Ancient' school of Tibetan Buddhism.