That shift was brought about by disruptive invasions, by the co-option of the Buddha in north India into a revived Hinduism (as an Avatar in the cult of Vishnu-worship), and in part by violent repression by a new devotional cult of Shiva-worshipers (bhakti), who slaughtered so many Jains they wiped out that faith in south India. The Asoka emperor (269-232 B.C.E.) was more kindly disposed, and sent out Buddhist missionaries to SriLanka and west Asia. Buddhism spread from north India to Bhutan, Burma, China, Indochina, Japan, Sri Lanka, Thailand, and Tibet.
It reached Southeast Asia in the 1st century C.E. Buddhism was introduced to China in the Han dynasty and enjoyed a ''golden age'' there from the 5th to the 9th centuries, until it was harshly repressed by the Tang from 845 C.E. In defense, Buddhist monasteries were rebuilt as mountaintop fortresses and housed thousands of well-trained and armed monks. A ''White Lotus'' sect of Buddhism evolved a military offshoot known as the Red Turbans, who were so adept at the martial arts they helped overthrow the Mongol (Yuan dynasty) in 1368. Classical Buddhism was rooted in the mystical traditions of ancient Indian belief, but was founded also as a reaction against Aryan ritual and rigidity. The Buddha rejected Brahman claims to simply inherit piety. Instead, he posited that suffering could be eliminated only through self-perfection and through prajna, or ''enlightenment,'' in which an end to Earthly woes came from the extinction of desire via the ''eightfold path'' (right conduct, effort, meditation, memory, occupation, resolve, speech, and views) of right living on the ''middle way'' between extremes of radical asceticism and hedonism.
Classical Buddhism thus stressed a tolerant, moderate, personal discipline and self-correction leading via a cycle of reincarnations to nirvana (in the Mahayana tradition, a condition of holiness, purity, and release from all desires and travails of earthly life-an end to suffering rather than a mystical paradise). One may halt the cycle of births and deaths only with full enlightenment and merger with the Buddha, the first being to achieve nirvana. This later led to development of the doctrine of ''Bodhisattvas,'' or enlightened souls, of whom the Buddha (Siddhartha) was the first. These great souls could intercede for the salvation of the still earth-bound and unenlightened. Along with elevation of Buddha to godhead came development of a monastic movement dedicated to preservation of the original doctrine-in short, Buddhism became more anthropomorphic as well as rigidly doctrinaire over time. As also happened in medieval Christianity, its monastic movement shifted from purist contemplation to great material wealth, lurched into radical reformism, then repeated the cycle in some variant form. A highly meditative version of Buddhism developed in China known as ''Chan'' (in Japan, ''Zen'').
Socially, Buddhism tended to promote fatalistic resignation by the masses, but encouraged charity and good works that gave rise to its hugely influential and widespread monastic movement. Buddhist monasteries played an important role in the accumulation of wealth and dissemination of learning and culture in Asia, directly comparable to the great Cistercian and other monastic movements in European history. Politically, Buddhism was associated with traditional kingship systems. In Japan, Buddhism thrived for many centuries before its monasteries and sectarian armies were crushed in the 16th century by Nobunaga Oda and Hideyoshi Toyotomi. Under the Tokugawa shoguns, Buddhism was co-opted to serve the bakufu state, though in Satsuma prefecture a break-away sect emerged that was heavily persecuted.
