Samye Monastery was founded in the 8th century during the reign of King Trisong Detsen with the help of the Indian Buddhist masters Padmasambhava and Shantarakshita, whom the king had invited to Tibet to help spread Buddhism. Padamasambhava is credited with subduing the local spirits and winning them over to Buddhism.
The importance of Samye to Tibetan Buddhism cannot really be overstated. Since its establishment in the eighth century, Samye has been the central point from where Tibetan Buddhism began to spread through Central Asia and beyond. It was also the place where many meditation practices were taught, translated, edited, maintained, and preserved, thus upholding and propagating the glorious Dharma.
It was in Samye Monastery that Vairocana, 108 scholars, and other Padmasambhava’s disciples first translated into Tibetan many of the texts that would make up Tibet’s vast Buddhist literature.
Padmasambhava performed the Vajrakilaya Dance and enacted the rite of ‘thread cross’ or Namkha to assist King Trisong Deutsen and Shantarakshita clear away obscurations and hindrances in the building of Samye. He performed this dance in order to prepare the ground for the Samye Monastery and to pacify the malice of the local mountain god spirits and malevolent spirits in order to create the most perfect conditions for the authentic dharma to be practiced.
In one of his teachings, the great master Longchenpa explained the great importance of Samye Monastery. He said you can measure whether Tibetan Buddhism will stay or be lost and gone forever by observing the condition of Samye Monastery. In this way, Samye is really the measure: if Samye is gone, Tibetan Buddhism will disappear.