Major world religion and philosophy founded in northeastern India between the 6th and the 4th centuries BCE. Based on the teachings of Siddhartha Gautama, called the Buddha, Buddhism takes as its goal the escape from suffering and from the cycle of rebirth: the attainment of nirvana. It emphasizes meditation and the observance of certain moral precepts. The Buddha's teachings were transmitted orally by his disciples; during his lifetime he established the Buddhist monastic order (sangha). He adopted some ideas from the Hinduism of his time, notably the doctrine of karma, but also rejected many of its doctrines and all of its gods. In India, the emperor Ashoka promoted Buddhism during the 3rd century BCE, but it declined in succeeding centuries and was nearly extinct there by the 13th century. It spread south and flourished in Sri Lanka and Southeast Asia, and it moved through Central Asia and China (including Tibet; seeTibetan Buddhism), Korea, and Japan (seePure Land Buddhism; Zen). In the 19th century, Buddhism spread to Europe and the United States, and it became increasingly popular in the West in the second half of the 20th century. Buddhism's main teachings are summarized in the Four Noble Truths, of which the fourth is the Eightfold Path. Buddhism's two major branches, Mahayana and Theravada, have developed distinctive practices and unique collections of canonical texts. In the early 21st century, the various traditions of Buddhism together had more than 375 million followers.