[4] In the twelfth century, Mahayana Buddhism developed in Northern India and traveled through Tibet, China and into Vietnam, Indonesia and beyond.
[4] Buddhism is thought to have entered Southeast Asia from trade with India, China and Sri Lanka during the 1st, 2nd and 3rd centuries.
One of the earliest accounts of Buddhism in Southeast Asia was of a Theravada Buddhist mission sent by the Indian emperor Ashoka to modern-day Burma in 250 BCE.
Theravada Buddhism spread from India to Sri Lanka then into the region as outlined above, and primarily took hold in the modern states of Burma, Cambodia, Laos, Thailand and southern Vietnam.
Mahayana took root primarily in maritime Southeast Asia, although there was also a strong influence in Vietnam, in part due to their connection with China.
Srivijaya, a maritime empire centred at Palembang on the island of Sumatra in Indonesia, adopted Mahāyāna and Vajrayāna Buddhism under a line of rulers named the Sailendras.
Notable example includes Kalasan, Manjusrigrha, Plaosan, and the grand stone mandala Borobudur, completed during the reign of Samaratungga (r. 819–838) in early 9th century.
The Mon people are an ethnic group from Burma (Myanmar) that contributed to the success of Theravada Buddhism within Indochina.
[9] Buddhism was likely introduced to the Mon people during the rule of Ashoka Maurya, the third emperor of the Mauryan Dynasty (268-232 BCE) in India.
[10] Ashoka ruled his kingdom in accordance with Buddhist law and throughout his reign he dispatched court ambassadors and missionaries to bring the teachings of the Buddha to the east and Macedonia, as well to parts of Southeast Asia.
[9] Hinduism was the primary religion of the Khmer Empire, with a smaller portion of people also adhering to Mahayana Buddhism.
During the Khmer Rule, Theravada Buddhism was only found in parts of Malaysia, northwest Thailand, and lower Burma.
Currently, the Southeast Asian countries with the highest amounts of practicing Theravada Buddhists are Myanmar, Thailand, Laos, and Cambodia.
That is in part due to the influence of German sociologist, Max Weber, who was a prominent scholar of religion that has had a significant impact on the way Southeast Asian Buddhism is studied.
Buddhism has also played a role in the consolidation of power and political resistance to throughout history, dating back to as early as the 10th and 11th century.
During the Nguyen dynasty of Vietnam in the 19th and 20th century, there was a strain between Confucian rulers and practitioners of Buddhism monks during the early unification of the empire.
The rulers had a fear of potential rebellions emerging from monastic sites in the countryside and heavily criticized the spiritual practices of Buddhist sects, including a belief in invulnerability based on merit.
These resistance movements were led by holy men or phu mi bun who had great power due to a high accumulation of merit.
This self-immolation was an act of protest of the regime of South Vietnamese President Ngo Dinh Diem, a member of the Catholic minority who ruthlessly persecuted and suppressed the Buddhist community.
[12] The Thai Sangha has led various Theravada Buddhist missionary works in Southeast Asia, South Asia, Europe, and North America, where most delegations focused on the United States, rather than Asian countries with dwindling Theravada Buddhist populations such as the Philippines, Indonesia, Timor-Leste, Brunei, and eastern Malaysia.