Trisong Detsen
Trisong Detsen (T. ཁྲི་སྲོང་ལྡེ་བཙན khri srong lde btsan) was the 38th king of the Yarlung dynasty, who ruled the Tibetan Empire from AD 755 until 797 or 804. Trisong Detsen was the second of the "Three Dharma Kings" of Tibet; the other two were Songtsen Gampo and Ralpacan.
While Buddhism was first introduced to Tibet during the reign of Songtsen Gampo, it was during the rein of Trisong Detsen that Buddhism became more firmly established. Trisong Detsen invited the great Indian masters Padmasambhava, Śāntarakṣita, Vimalamitra, and others to come to Tibet and teach the Dharma. These masters assisted in building the first monastery in Tibet (Samye Monastery) and in ordaining the first group of Tibetan monks.
Trisong Detsen was succeeded on the throne by his second son, Muné Tsenpo, who died after ruling for barely one year. The throne then passed to his youngest son Senaleg.
See also:
King Trisong Detsen, Rigpa Shedra Wiki- Trisong Detsen (Wikipedia)