Thailand
Formerly known as Siam, Thailand became a constitutional democracy in 1932. Buddhism (almost entirely of the Theravāda form) plays a leading role in all aspects of national life, and since the Saṃgha Administration Act of 1902 has enjoyed constitutional status as the official religion. Under this measure a religious hierarchy was created presided over by a supreme patriarch (saṃgha-rāja) who is appointed by the king. Because of this link between Buddhism and nationalism, it is traditional for all young men to spend a short period of time as monks, usually during the three-month rainy-season retreat. Most parents would consider it a great honour should their son wish to prolong his stay and take up the religious life on a permanent basis, but for most it is a kind of ‘national service’ forming a step on the way to an alternative professional career.
The Pāli chronicles refer to Thailand as Sāmindavisaya, and speak of a close relationship between it and Sri Lanka dating back to the Middle Ages. Monks were sent from Thailand to restore the ordination lineage in Sri Lanka when Buddhism had fallen into decline there. The original inhabitants of the region were the Mons, who may have been introduced to Theravāda Buddhism in the early centuries ce by missionaries sent from India by Aśoka. It became firmly established in those areas of the Mon kingdom known as Haripuñjaya and Dvāravatī. From the 5th to the 15th century, an important power in the area was the Khmer Empire, in which various forms of Hinduism and Mahāyāna Buddhism were also popular. In the 11th century, missionaries were sent from Burma, and the Thai people arrived in the region having been displaced from China by the Mongols. They found the Theravāda form of Buddhism congenial and it began to displace Mahāyāna forms. Around 1260 the kingdom of Sukhothai became independent from the Khmers and King Rama Khamheng (1275-1317) declared Theravāda the state religion. Sukhothai fell in 1492 and was replaced by the kingdom of Ayudhya, which ruled until 1767. During this time an edition of the Pāli Canon was produced by King Songdharm (r. 1610-28) and relations between the Saṃgha and the crown became closer. Ayudhya was overthrown by Rama I (1782-1809) who founded the Chakri dynasty and devoted himself to the purification of the Saṃgha. One of his successors, Mongkut (Rama IV, r. 1851-78) was himself a monk for 27 years before becoming king. Having been a member of the strict Thammayut order (which he himself founded) he decreed on becoming king that all monks, including those of the majority Mahānikai (Pāli, Mahānikāya) should henceforth observe the stricter disciplinary practices. Although monks are the main source of religious authority, lay groups have also been established in recent times, and many Thais are pressing for a more modern outlook on the part of the clergy and an updating of the ancient teachings to make them more relevant to the problems of contemporary life.