Thai Buddhism was based on the religious movement founded in the sixth century B.C. by Siddhartha Gautama Sakyamuni, later known as the Buddha, who urged the world to relinquish the extremes of sensuality and self-mortification and follow the enlightened Middle Way. The focus was on man, not gods ÍÍÍÍthe assumption was that life was pain or suffering, which was a consequence of craving, and that suffering could end only if desire ceased. The end of suffering was the achievement of nirvana (in Theravada Buddhist scriptures, nibbana), often defined negatively as the absence of craving and therefore of suffering, sometimes as enlightenment or bliss.

By the third century B.C., Buddhism had spread widely in Asia, and divergent interpretations of the Buddha's teachings had led to the establishment of several sects. The teachings that reached Ceylon (present-day Sri Lanka) were given in a final written form in Pali (an Indo-Aryan language closely related to Sanskrit) to religious centers there in the first century A.D. and provided the Tipitaka (the scriptures or "three baskets" in Sanskrit, Tripitaka) of Theravada Buddhism. This form of Buddhism reached what is now Thailand around the sixth century A.D. Theravada Buddhism was made the state religion only with the establishment of the Thai kingdom of Sukhothai in the thirteenth century A.D. (see Early History , ch. 1).

The details of the history of Buddhism in Thailand from the thirteenth to the nineteenth century are obscure, in part because few historical records or religious texts survived the Burmese destruction of Ayutthaya, the capital city of the kingdom, in 1767. The anthropologist-historian S.J. Tambiah, however, has suggested a general pattern for that era, at least with respect to the relations between Buddhism and the sangha on the one hand and the king on the other hand. In Thailand, as in other Theravada Buddhist kingdoms, the king was in principle thought of as patron and protector of the religion (sasana) and the sangha, while sasana and the sangha were considered in turn the treasures of the polity and the signs of its legitimacy. Religion and polity, however, remained separate domains, and in ordinary times the organizational links between the sangha and the king were not close.

Among the chief characteristics of Thai kingdoms and principalities in the centuries before 1800 were the tendency to expand and contract, problems of succession, and the changing scope of the king's authority. In effect, some Thai kings had greater power over larger territories, others less, and almost invariably a king who sought successfully to expand his power also exercised greater control over the sangha. That control was coupled with greater support and patronage of the ecclesiastical hierarchy. When a king was weak, however, protection and supervision of the sangha also weakened, and the sangha declined. This fluctuating pattern appears to have continued until the emergen b52ce of ththe Chakkri Dynasty in the last quarter of the eighteenth century.

By the nineteenth century, and especially with the coming to power in 1851 of King Mongkut, who had been a monk himself for twenty-seven years, the sangha, like the kingdom, became steadily more centralized and hierarchical in nature and its links to the state more institutionalized. As a monk, Mongkut was a distinguished scholar of Pali Buddhist scripture. Moreover, at that time the immigration of numbers of Mon from Burma was introducing the more rigorous discipline characteristic of the Mon sangha. Influenced by the Mon and guided by his own understanding of the Tipitaka, Mongkut began a reform movement that later became the basis for the Dhammayuttika order of monks. Under the reform, all practices having no authority other than custom were to be abandoned, canonical regulations were to be followed not mechanically but in spirit, and acts intended to improve an individual's standing on the road to nirvana but having no social value were rejected. This more rigorous discipline was adopted in its entirety by only a small minority of monasteries and monks. The Mahanikaya order, perhaps somewhat influenced by Mongkut's reforms but with a less exacting discipline than the Dhammayuttika order, comprised about 95 percent of all monks in 1970 and probably about the same percentage in the late 1980s. In any case, Mongkut was in a position to regularize and tighten the relations between monarchy and sangha at a time when the monarchy was expanding its control over the country in general and developing the kind of bureaucracy necessary to such control. The administrative and sangha reforms that Mongkut started were continued by his successor. In 1902 King Chulalongkorn (Rama V, 1868-1910) made the new sangha hierarchy formal and permanent through the Sangha Law of 1902, which remained the foundation of sangha administration in modern Thailand.

Data as of September 1987