Samye was the first monastery to be built in Tibet. It was probably founded during the 770's under the patronage of King Trisong Detsen, with the work being directed by Padmasambhava and Shantarakshita, the two Indian masters that the king had invited to Tibet. The monastery is designed on the plan of the Odantapuri temple in India (present-day Bihar), and mirrors the structure of the universe according to Buddhist cosmology. The central temple represents Mt. Sumeru, the mythical mountain at the centre of the cosmos. Around it are four temples called 'ling', which represent the four continents (ling) situated in the vast ocean to the north, south, east, and west of Sumeru. To the right and left of each of these are smaller temples, called 'ling-tren', representing sub-continents. Four great stupas, in four colours (white, red, blue and green) stood facing the (south-east, south-west, north-west, and north-east, respectively) corners of the main temple, andare being reconstructed. Near the North (Jangchub Semkye) ling, is a protector chapel, Pehar Kordzoling, adorned with unusual mural work featuring skulls. One ling-tren, the Dragyur Gyagar Ling (South-South-West) was established for the sole purpose of translating sutras. Beyond its front entrance is an idyllic courtyard, planted with flowers, trees, and bamboo.

When the monastery was first built, both Indian and Chinese monks were invited there to work on the translation of Buddhist scriptures from their respective languages into Tibetan. The Indians lived in the Aryapalo (Hayagriva) Ling temple to the south, and the Chinese in the Jampa (Maitreya) Ling to the west. Conflicts arose between the two factions concerning doctrinal interpretation, and the king called for a public debateto settle the matter. This took place around 792, between Kamalashila, adisciple of Shantarakshita, and Hoshang. The debate, which took place in the Jampa Ling, was presided over by Trisong Detsen, and was intended to establish which form of Buddhism should prevail in Tibet: the Indian monastic tradition of systematic study, firm adherence to ethical rules, and a practice that entails the gradual ascendance of stages leading to enlightenment; or the Chinese tradition of Ch'an (Zen), which favours a direct ('sudden') breakthrough to the ultimate nature of consciousness and existence, for which intellect and morality, the twin pillars of the Indian school, are not necessary, and can even be hindrances. The accounts of the outcome of the debate are ambiguous, both sides claiming victory. The actual outcome, though, is beyond doubt: The Indian view was favoured, and from then on the Chinese influence waned. Hoshang had to leave Tibet, and the Ch'an tradition was effectively proscribed.