Theravāda () (, , , , , , ) is the most commonly accepted name of Buddhism's oldest existing school. The school's adherents, termed Theravādins, have preserved their version of Gautama Buddha's teaching or Buddha Dhamma in the Pāli Canon for over two millennia. The Pāli Canon is the most complete Buddhist canon surviving in a classical Indian language, Pāli, which serves as the school's sacred language and lingua franca. In contrast to Mahāyāna and Vajrayāna, Theravāda tends to be conservative in matters of doctrine (pariyatti) and monastic discipline (vinaya). One element of this conservatism is the fact that Theravāda rejects the authenticity of the Mahayana sutras (which appeared c. 1st century BCE onwards). Modern Theravāda derives from the Mahāvihāra order, a Sri Lankan branch of the Vibhajjavāda tradition, which is, in turn, a sect of the Indian Sthavira Nikaya. This tradition began to establish itself in Sri Lanka from the 3rd century BCE onwards. It was in Sri Lanka that the Pāli Canon was written down and the school's commentary literature developed. From Sri Lanka, the Theravāda Mahāvihāra tradition subsequently spread to the rest of Southeast Asia. It is the official religion of Sri Lanka, Myanmar and Cambodia, and the dominant religion in Laos and Thailand and is practiced by minorities in India, Bangladesh, China, Nepal, North Korea and Vietnam. The diaspora of all of these groups, as well as converts around the world, also embrace and practice Theravāda Buddhism. During the modern era, new developments have included Buddhist modernism, the Vipassana movement which reinvigorated Theravāda meditation practice, the growth of the Thai Forest Tradition which reemphasized forest monasticism and the spread of Theravāda westward to places such as India and Nepal, along with Buddhist immigrants and converts in the European Union and the United States. History Pre-Modern The Theravāda school descends from the Vibhajjavāda, a division within the Sthāvira nikāya, one of the two major orders that arose after the first schism in the Indian Buddhist community. Theravāda sources trace their tradition to the Third Buddhist council when elder Moggaliputta-Tissa is said to have compiled the Kathavatthu, an important work which lays out the Vibhajjavāda doctrinal position. Aided by the patronage of Mauryan kings like Ashoka, this school spread throughout India and reached Sri Lanka through the efforts of missionary monks like Mahinda. In Sri Lanka, it became known as the Tambapaṇṇiya (and later as Mahāvihāravāsins) which was