History of Tibetan religion
In the 7th century, the Tubo Kingdom emerged on the Tibetan Plateau after Songtsan Gambo (?-650) unified the Tibetan Plateau. He introduced Buddhism into Tibet to defy the original religious – Bon. He married Princess Bhributi from Nepal, who brought a life-sized statue of Sakyamuni at the age of eight, and then married Princess Wencheng of the Tang Dynasty (618-907), who brought a life-sized statue of Sakyamuni at the age of 12, as well as 360 volumes of Buddhist sutras as her dowry. From then on, Buddhism started to flow into Tibet from India and the central plains at one time. In the following 100 years, Buddhism and Bon were conflicting incessantly. The first large-scale Buddhist monastery in Tibet started in the late 8th century. By the early 9th century, more monasteries were constructed, and the influence of Buddhism in Tibet reached its zenith.
In the middle of 9th century of the reign of Lang Darma, Buddhism was persecuted, known as “Lang Darma Persecution of Buddhism” in the history. Then, the Bon Religion revived. Tibetan Buddhism became almost extinct. Then, Buddhism flow into Tibet and became popular again, but it emerged many sects reflecting political loyalties
Tibetan Buddhism history is divided into two periods by historians. The period from the reign of Songtsan Gambo to that of Darma as the "Early Period of Buddhism”, the period after “Lang Darma Persecution of Buddhism” and the renaissance of Buddhism as the "Later Period of Buddhism".
Many monasteries were constructed in Tibet during the Early Period of Buddhism, such as Jokhang Temple, Ramge Monastery, Samye Monastery and Potala Palace, etc. However, few of the monasteries constructed in the Early Period of Buddhism remain apart from ruins. Great changes took place in the monasteries in Tibet in the Later Period of Buddhism in both their architectural styles and their social functions. During this period, feudal serf-owners were usually the biggest benefactors or lamas of the monasteries, leading to a fusion of politics and religion. In the mid 13th century, religious leaders appointed by the Central Government administered local affairs. In the Ming (1368-1644) and Qing (1644-1911) dynasties, the policy of "integration of state and religion" in Tibet continued. For these several centuries, the local religious leader served as the ruler of his area, integrating politics, military affairs, economy and religion, leading to changes in the structures and functions of monasteries in Tibet.

Nowadays there are no conflicts among religions or among the different sects of Buddhism in Tibet. Modern civilization has not only brought great changes to Tibet, but also make the divine light shine even more brightly forth from the region's monasteries.
In the past few decades, the Central Government of China has invested a lot to protect and improve the Buddhism constructions.