sourced story
Late 13th century CEReputable source · 2 sourcesWell documented

Theravada Buddhism Becomes the State Religion of Southeast Asia

A Cambodian king's Mahayana faith gives way to a Sri Lankan import that outlasts his empire

On the timeline · around Late 13th century CE · Buddhism in East and Southeast AsiaMahayana and VajrayanaBuddhism in East and Southeast AsiaTheravada Buddhism Becomes the State Religion of Southeast Asia11001150120012501300135014001450

Quick facts

Jayavarman VII's reign
1181-1215 CE
Theravada introduced from
Sri Lanka
Theravada dominant in Khmer world by
Late 13th century CE
Sukhothai king who adopted Theravada
Ram Khamhaeng (r. c. 1275-1298 CE)

What happened

The Khmer Empire's greatest king, Jayavarman VII (r. 1181-1215 CE), rebuilt Angkor after it was sacked by the Chams and turned the new state temple, the Bayon, toward Mahayana Buddhism, reportedly encouraged by his devoutly Buddhist wife Indradevi. That royal Mahayana patronage did not last as the region's dominant form of Buddhism. From the late 13th century onward, Theravada Buddhism, introduced from Sri Lanka, prevailed across the Khmer world even among the lower classes, and the same pattern played out in neighboring Thailand: the Sukhothai king Ram Khamhaeng (r. c. 1275-1298 CE) formally adopted Theravada as Sukhothai's official state religion, with Sri Lankan and Indian artistic influence visible in Sukhothai's temple architecture.

Why it matters

The shift from royally sponsored Mahayana to popularly rooted Theravada across Cambodia and Thailand shows Buddhism moving in the opposite direction from a top-down imperial project, spreading instead through monastic networks reaching ordinary people, and it set the religious pattern, Theravada as the majority faith, that both countries retain today.

How we know

Jayavarman VII's temple-building and religious patronage are documented through inscriptions and the surviving architecture of Angkor Thom and the Bayon, while Theravada's later dominance and Ram Khamhaeng's adoption of it as Sukhothai's state religion are recorded in the region's own historical and archaeological record, including surviving Sukhothai-era temples showing Sri Lankan stylistic influence.

Sources

  • World History Encyclopedia. Khmer Empire · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
  • World History Encyclopedia. Sukhothai · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)

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Related timelines

  • The Khmer Empire · See the Khmer Empire timeline for Jayavarman VII's reconstruction of Angkor and the temple-building program that first brought Mahayana Buddhism to the Khmer state religion.
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