It is believed in traditional Tibetan history that the spread of Buddhism to Tibet was brought about by holy activities of Buddhas and Bodhisattvas. The spread of Buddhism to Tibet was prophesied by Lord Buddha himself in the Manjusrimulatantra.
Prior to the spread of Buddhism to Tibet, Tibetan's indigenous religion and culture was Bon. Buddhism began to spread to Tibet in two disseminations beginning with period of the Three Great Religious Kings. The first religious king was the Srong-btsan-sgam-po of the Yar Lung dynasty, 33rd in the royal linage (ca. 618-650). This king was the emanation of the Bodhisattva Avalokitesvara and he opened the door and established both the Buddhist religion and the political order. He built the great Potala palace and two temples in Lhasa. Under his reign, a legal system combining religious and secular principles was established. The king himself also gave moral teachings of Bodhisattva Avalokitesvara.
The second religious king was Khri-srong-Ide'u-btsan, 37th in the royal line, an emanation of the Bodhisattva Manjushri (ca. 740-798). In this period, Buddhism flourished immensely with the coming together of the Abbot- Santaraksita and the Preceptor- Padmasambava who were invited to Tibet by the King. From here, the translations of Buddha's teachings were carried out, the assemblies of monks were established and the first monastery in Tibet, the temple of Samye was built. The two systems of laws- the religious law and the laws of the kingdom, was further spread and strengthened.
The third religious king was Lord Ral-pa-can, 39th in the royal line and an emanation of Vajrapani. This king continued to build Buddhist monasteries and by royal edict, he appointed seven families for the support of each group of four monks. He also standardized the translation language for religious texts and established the methods of translations and transmissions of Buddha's teachings.
The death of Ral-pa marked the end of the first dissemination in Tibet, after which Buddhism went quiet in Tibet. Buddhism was revived in 1042 in Tibet, with the arrival of Lord Atisha marking the start of the second dissemination. From hereon, Buddhism firmly established its roots in Tibet. In 1244, Sakya Pandita, the head of the Sakya Tradition of Tibetan Buddhism, became the ruler of the whole of Tibet when he was appointed regent by the Mongol ruler Godan. In 17th century, the Gelupas became rulers of Tibet and in 1642, the 5th Dalai Lama (1617-1682) became the first Dalai Lama to rule Tibet, this tradition continued until today until the 14th Dalai Lama (b. 1935) fled Tibet after the change of circumstances there in 1959.
Four schools of the Tibetan Buddhism had arisen in the first and second disseminations of Buddhism to Tibet.
The Nyingma Tradition is the oldest school of Tibetan Buddhism, which was founded during the first disseminations of Buddhism to Tibet in 8th century. The remaining three schools were founded in the second dissemination.
The Kagyu Tradition was founded by Marpa, Milarepa and Gampopa. This tradition stemmed from the teachings of great Indian Mahasiddhas such as Naropa and Tilopa.
The Gelugpa Tradition was founded by the 14th century philosopher Lama Tsong Khapa and during 17th century which became the dominant political force in central Tibet.
The Sakya School was founded by Khon Konchok Gyalpo in 1073 where he established the Sakya monastery in south central of Tibet. This tradition stemmed from the teachings of great Indian Mahasiddha Virupa. Within the Sakya School, there is the principal branch of Sakya and the three main sub-sects of Ngorpa, Dzongpa and Tsharpa.
