Chapter 3. Southeast Asia: Myanmar, Thailand, Cambodia, and Laos¶

Theravāda Buddhism's spread from Sri Lanka to Southeast Asia was not a single coordinated missionary movement. It took six or seven centuries and followed multiple routes. It proceeded in stages under different political conditions. Myanmar, Thailand, Cambodia, and Laos all belong to Southern Theravāda today, but each has its own historical layers. Their connections are considerably more complex than the apparent unity of tradition and origin suggests. They involved direct transmission from Sri Lanka, lateral influence among regions, and several reverse flows from Southeast Asia back to Sri Lanka. This chapter traces the tradition's arrival in each region before considering the resulting map as a whole.

I. Overview of the essential premises¶

Theravāda was not the first Buddhism in this region. Before its arrival, mainland Southeast Asia already had a long history of composite religious traditions combining Buddhism, including Mahāyāna and esoteric forms, with Hinduism. In most countries, establishing Theravāda meant changing an existing religious configuration, not planting seeds in empty ground.

The Mon were crucial intermediaries. They played a central role in transmission between Sri Lanka and Myanmar and Thailand. The Mon lived in what is now southern Myanmar and central Thailand, and established maritime connections with Sri Lanka early on. They developed their own Theravāda tradition and subsequently brought it into Bamar and Tai polities.

Royal power is the axis of this history. In almost every country, the establishment of Theravāda was actively promoted by one or more kings. They funded the saṅgha, invited monks, sent emissaries to Sri Lanka for scriptures and ordination, and unified the internal order in the name of the Dharma. Theravāda took root in Southeast Asia because it met the dynasties' need for a common spiritual framework that could transcend tribal divisions, as well as a religious narrative legitimizing the king.

Dependence also ran in reverse. The most striking episode occurred in eighteenth-century Sri Lanka, when its ordination lineage had almost died out. The island turned to Thailand for monks and received renewed full ordination from there, giving rise to the Siam Nikāya. The source borrowed ordination from a recipient, showing that the relationship between a tradition's origin and its later branches was never one-way.

II. Myanmar, its Mon foundations, and consolidation under Pagan¶

Before Pagan¶

The earliest historically attested system of states in the Myanmar region was that of the Pyu, roughly from the second to ninth centuries CE, in the dry zone of present-day central Myanmar. The religious remains of Pyu cities such as Śrī Kṣetra and Beikthano are diverse. Images of Viṣṇu and Śiva appear at Beikthano from the first and second centuries CE. Brahmanism, Hinduism, Buddhism, and local spirit beliefs coexisted. Buddhism was only one strand, far from a Theravāda monopoly. The Pyu declined in the ninth century. In 832 and 835, Nanzhao in Yunnan successively sacked Hanlaṅ, the last great Pyu city in central Myanmar, and Mi-chrēn, a Mon city in Lower Myanmar.¹

The Mon of southern Myanmar had more direct connections with Sri Lanka. They are said to have received Theravāda scriptures and ordination lineages from Sri Lanka by sea quite early, perhaps in the fifth to sixth centuries. Their kingdom of Thaton became one of the region's earliest firmly established Theravāda centers.

Pagan and Anawrahta¶

The king who established Theravāda as Myanmar's mainstream tradition was Anawrahta, who reigned around 1044–1077 in the Pagan dynasty, which lasted approximately 849–1297.

According to the traditional narrative, the Mon bhikkhu Shin Arahan came from Thaton to Pagan, taught Anawrahta, and converted him. The king then conquered Thaton and brought back a large body of Pali texts, along with many Mon monks and artisans. The story of thirty-two elephants carrying the scriptures is widely circulated. The king formally established Theravāda as the state religion.²

The narrative is heavily mythologized, and thirty-two elephants is an auspicious number. This book doubts the specific details, but regards the core structure as a credible historical framework. The Mon served as intermediaries, while political conquest and religious transmission proceeded together. Anawrahta was a historical king, and the extensive archaeological remains of Pagan-period monasteries and stupas corroborate the scale of this religious construction.

From the eleventh to thirteenth centuries, Pagan became one of Southeast Asia's most important Theravāda centers. More than two thousand monastic and stupa remains survive. It was also an active center of Pali textual study and Abhidhamma learning. The high value placed on Abhidhamma in Myanmar's later tradition is already evident here. The pronounced emphasis on specialized Abhidhamma study, however, is generally dated to the seventeenth century onward.³

The Pagan dynasty disintegrated around 1287. The sources are unclear about whether Mongol troops actually entered Pagan. Theravāda was already firmly rooted, however, and later dynasties such as Ava continued to present themselves as protectors of the Dharma. In the fifteenth century, further ordination lineages from Sri Lanka, transmitted through Chiang Mai in present-day northern Thailand, entered Myanmar. They competed with established lineages and provided the historical origins of later Nikāyas, or monastic fraternities.

The depth of Myanmar's Abhidhamma tradition¶

The exceptional depth of Myanmar's Abhidhamma tradition deserves separate attention. Myanmar accords very high status to the study of works such as the Abhidhammatthasaṅgaha, with distinct educational systems for monks devoted to learning (Pariyatti-sasanā) and monks devoted to practice (Paṭipatti-sasanā). The former specialize in textual study and the latter in meditation, and each has its own tradition. The twentieth-century revival of insight meditation, including the Mahāsi tradition discussed in 9.5, arose within this tradition of valuing Abhidhamma.

III. Thailand, Dvāravatī's Mon foundations, and the formation of Sukhothai¶

Dvāravatī as the Mon Theravāda predecessor¶

Before the Tai established their own kingdoms, the Mon Theravāda Buddhist state of Dvāravatī already existed in the central plains of present-day Thailand, around the sixth to eleventh centuries. Its Buddhist archaeological remains include carved stone Dharma wheels, inscriptions in Mon, Sanskrit, and Pali, and stupa sites at places such as Nakhon Pathom and U Thong. These share clear foundations with contemporary Mon traditions in Myanmar.⁴

After the eleventh century, Angkor's Khmer empire expanded westward and Dvāravatī declined. Central Thailand entered the Khmer cultural sphere, with a court culture combining Brahmanism and Mahāyāna Buddhism. This supplied the historical basis of the Khmer court influence in later Thai Buddhism.

Sukhothai and Lan Na¶

Sukhothai, around 1238–1438, was the first independent kingdom established by the Tai. King Ram Khamhaeng, who reigned around 1279–1298, is known for creating the Thai alphabet and promoting Theravāda Buddhism. One of his inscriptions, the earliest surviving inscription in Thai, describes a society organized around the Dharma. The king associates closely with monks and sets a throne before the palace for their preaching. The people worship the Buddha freely.⁵

One source of Sukhothai-period Theravāda was Nakhon Si Thammarat in present-day southern Thailand, which had long maintained direct maritime links with Sri Lanka. During Ram Khamhaeng's reign, this Sri Lankan lineage entered the Sukhothai court and became the orthodoxy recognized by royalty.

At the same time, Lan Na in northern Thailand, around 1292–1558 in the present Chiang Mai region, developed into another Theravāda center. In the 1430s, Lan Na invited fully ordained monks from Sri Lanka and held an important disciplinary purification ceremony at Chiang Mai, establishing a lineage that took Sri Lankan ordination as its standard. This Lan Na lineage later sent monks and texts to Myanmar and Laos as well.

Ayutthaya and Buddhism at court¶

Ayutthaya, 1351–1767, was a longer-lasting and more influential Tai kingdom. It coexisted with Sukhothai before replacing it. Its court culture was deeply influenced by Khmer Angkor. The king appeared as a god-king (devarāja), and court ceremonies combined brahmanical and Buddhist elements. The king was also Buddhism's great patron.

The model of Buddhist kingship recurred across Southeast Asian dynasties. The king was a Dharma king whose legitimacy depended on protecting and purifying the saṅgha. The model was a structural feature of deep integration between politics and religion, not merely a religious coloring on the surface.

In 1767, Burmese forces captured Ayutthaya and ended the dynasty. During the comprehensive reconstruction under the subsequent Bangkok, or Rattanakosin, dynasty, an important Buddhist reform took place, as discussed in 9.5.

IV. Cambodia's transition from Angkorian Mahāyāna to Theravāda¶

Religious plurality under Angkor¶

The Khmer empire, or Angkor dynasty, around 802–1431, was one of ancient Southeast Asia's most powerful polities. At its height, it covered present-day Cambodia, most of Thailand, southern Laos, and southern Vietnam.

Angkor's religious order involved the long coexistence and rivalry of Hinduism and Buddhism, with kings moving between them according to personal preference. Most were Śaivas, a few worshipped Viṣṇu, and only a few were Buddhists.

The most important exception was Jayavarman VII, who reigned around 1181–1218. He was Angkor's last great builder and the only monarch in Cambodian history to leave extensive architectural remains as a Mahāyāna Buddhist king. Angkor Thom, the Bayon, and Ta Prohm all date from this period. The Bayon is known for its many faces, generally understood as images of the king embodying a bodhisattva, or of Avalokiteśvara.⁶

After his death, his successors restored a Hindu orientation and destroyed some Mahāyāna sculptures. The reversal shows that Mahāyāna never achieved lasting dominance at Angkor. Its flourishing depended heavily on individual rulers' support.

The turn to Theravāda in the thirteenth to fifteenth centuries¶

Angkor's religious configuration began to change fundamentally around the thirteenth century. Theravāda entered from the direction of Thailand. During Sukhothai's expansion, the Tai brought a Theravāda tradition with Mon foundations and the authority of Sri Lankan transmission behind it. At the same time, Angkor's royal power declined rapidly under repeated external blows (the continuing Tai threat).

By the fourteenth to fifteenth centuries, Theravāda had clearly displaced Mahāyāna and Hinduism as the mainstream tradition. In 1431, Thai forces from Ayutthaya captured Angkor. The Khmer court relocated to the vicinity of present-day Phnom Penh and became more closely connected with the Thai cultural sphere, whose Buddhism was Theravāda. This political relocation hastened the final consolidation of the religious order.⁶

The historical irony is that Angkor's most striking Buddhist heritage, the Bayon's Mahāyāna faces, predates the full establishment of Theravāda. The Buddhist images most visitors see at Angkor today are Mahāyāna remains, not the tradition of contemporary Cambodian Theravāda.

In the twentieth century, Cambodian Buddhism suffered the most devastating blow in its history. Under Khmer Rouge rule from 1975 to 1979, monks were killed on a massive scale and monasteries were destroyed or repurposed. The tradition was almost extinguished. Its subsequent reconstruction belongs to another period, mentioned in 9.5.

V. Laos, Lan Xang, and the establishment of Theravāda¶

Theravāda became established in the Lao region relatively late, closely associated with the founding of Lan Xang, the "Land of a Million Elephants," 1353–1707.

Its founder, King Fa Ngum, lord of muang Sua from 1353 and deposed around 1374, was exiled to Angkor with his father in his youth after his father seduced a consort of the lord of Luang Phrabang. At Angkor he married the Khmer princess Keo Keng Nya. Late in 1351, he was dispatched north at the head of a largely Khmer army, bringing the various muang under his rule and founding Lan Xang. Later chronicles credit him with introducing Buddhism to Laos, but the source used here explicitly corrects that claim. Buddhism was already widespread in the region, and Lan Xang was simply the first Buddhist kingdom with its capital at Luang Phrabang. The Phra Bang Buddha image originated in Ceylon. During Fa Ngum's reign, missionary monks from Angkor brought it only as far as Vientiane. A hundred and fifty years later, King Vixun, who reigned from 1501 to 1520, brought it to the capital and installed it as the protective sacred image of the Lan Xang kings. The capital was thereafter called Luang Phrabang, the city of Phra Bang. The image remains Laos's most important religious symbol.⁷

The immediate source of Lao Theravāda was therefore a tradition transmitted through the Khmer. It did not come directly from Sri Lanka, but from Cambodian Buddhism already shaped by Khmer court culture, supplemented by the later Thai–Lan Na tradition transmitted through Chiang Mai. This double origin makes Lao Buddhism particularly close in style to northern Thai Buddhism, especially the Lan Na tradition.

After the seventeenth century, Lan Xang broke into the three smaller kingdoms of Luang Phrabang, Vientiane, and Champasak. Each continued the Theravāda tradition until their incorporation into French Indochina under modern French colonial power.

VI. Continuing exchange between Sri Lanka and Southeast Asia¶

Taken together, these histories show that relations between Sri Lanka and Southeast Asia were far more than a one-way process of Sri Lankan transmission and Southeast Asian reception. A more accurate description is repeated exchange in both directions over several centuries:

Labels and connections in the Chinese diagram, "Two-way exchange between Sri Lanka and Southeast Asian Theravāda": Sri Lanka (Mahāvihāra; Pāli canon) points to Mon Theravāda in southern Myanmar and central Thailand, labelled "fifth–tenth centuries; transmitted through the Mon." Mon Theravāda points to Burmese Theravāda (Pagan–Ava), labelled "eleventh century; with Pagan’s unification." Burmese Theravāda points to central Thai Theravāda (Dvāravatī), labelled "sixth–eleventh centuries; Dvāravatī." Central Thai Theravāda points upward to Lanna (Chiang Mai; Vinaya reform), labelled "fifteenth century; through Chiang Mai." Lanna points to Myanmar (fifteenth century), labelled "monks and texts transmitted," and to Laos (Lanna influence). Central Thai Theravāda also points to Cambodia (Khmer), labelled "fourteenth century; with King Fa Ngum," and separately to "incorporation into Tai culture." Its downward arrow leads to Sukhothai–Ayutthaya (Thailand), labelled "twelfth–thirteenth centuries; monks sent directly; Nakhon Si Thammarat in southern Thailand → Sukhothai." The long returning arrow begins at Sukhothai–Ayutthaya and ends at Sri Lanka, labelled "eighteenth century; monks sent to Sri Lanka to restore the ordination lineage."

These are the source diagram’s labels and arrows, not a verified sequence of historical transmissions. The diagram links nodes bearing earlier and later dates in an order that should not be read as a single chronology. Its placement of King Fa Ngum beside Cambodia differs from the chapter’s account of his connection with Laos and Lan Xang, including his Khmer ties. The chapter expressly identifies the eighteenth-century restoration of ordination as assistance from Siam (Thailand) to Sri Lanka in 1753.

The final arrow is the most revealing. By 1753, several centuries of warfare had brought Sri Lanka's bhikkhu ordination lineage close to extinction. Too few fully ordained bhikkhus remained to conduct an ordination act together. Sri Lanka sought help from Siam, or Thailand, which sent bhikkhus at its invitation. They renewed ordination ceremonies in Sri Lanka and established the Siam Nikāya, now the island's largest fraternity.⁸ Sri Lanka, which had transmitted the tradition, borrowed its ordination lineage back from Southeast Asia, which had received it.

This reverse flow also shows that the unity of Southern Theravāda does not imply an eternally stable center that continually transmits outward. Relations among regional traditions form a dynamic network, changing with historical conditions.

VII. Shared features and regional differences¶

The preceding sections reveal several shared structural features among Southeast Asian Theravāda traditions, as well as differences.

Shared features:

• They take the Pali Tipiṭaka as canonical and accord high authority to Buddhaghosa's commentarial tradition, especially the Visuddhimagga, while differing in curricula and traditions of practice.
• All have experienced moments of introducing or rebuilding full-ordination lineages from Sri Lanka.
• All developed deep integration between saṅgha and royal power. Kings presented themselves as protectors of the Dharma, and the saṅgha conferred legitimacy in return.
• All have differentiated forest and urban traditions, the former emphasizing meditative concentration and the latter scriptural study and community service.

Principal differences:

An observation deserves emphasis: Theravāda's establishment in Southeast Asia has always been accompanied by a narrative of purification in some sense. Each introduction of a new ordination lineage from Sri Lanka was described as correcting a local tradition that had degenerated. The narrative itself had a political function, allowing new centers of power, whether Anawrahta, Ram Khamhaeng, or Fa Ngum, to establish their legitimacy through religious reform. This book asks readers to read purification narratives as political acts while also recognizing the institutional renewal they brought.

The next chapter turns to doctrine and meditation traditions themselves. Southern Theravāda's philosophical positions and system of practice are the central subject of this part.

Further reading¶

• Donald K. Swearer. The Buddhist World of Southeast Asia. 2nd ed. Albany: SUNY Press, 2010. The book provides an overview of Southeast Asian Theravāda, treating the countries' shared features and differences together.

References¶