From Rigpa Wiki
Mutik Tsenpo (Wyl. mu tig btsan po) — one of the three (or four?) sons of King Trisong Detsen, born to Queen Droza Changchub, and a disciple of Padmasambhava. He later became known as Tridé Songtsen (Wyl. khri lde srong btsan) or Senalek (Wyl. sad na legs) and succeeded to Mune Tsenpo as King of Tibet. He reigned for approximately ten years (from 804 to 814 or 817) and further encouraged the propagation of the Buddhist teachings in Tibet. He had five sons, of whom Tri Ralpachen and Langdarma both reigned as kings of Tibet. His second son, Gyalsé Lharjé, was the immediate incarnation of his father, Trisong Detsen.