To Protect Thainess, Thailand First Had to Erase the Khmer

 

For nearly a century, Thailand’s nation-building project has relied on a careful rewriting of history—one that absorbs Khmer cultural achievements into the Thai narrative while erasing the people who created them. This curated past remains central to how the modern Thai state defines its identity, its prestige, and its claims over regional heritage.

To reinforce the belief that Thailand was never colonized and to elevate national pride, the Siamese state pursued a deliberate campaign to reinterpret cultures shaped by older regional civilizations—especially those of Khmer origin—as inherently Thai.

Between the 1930s and 1950s, this agenda hardened under the ideology of khwam pen thai or “Thainess,” which sought to define who belonged in the nation and who did not.

This ideology reshaped everyday life. Schools outlawed the Khmer language, and Khmer-speaking communities were discouraged—and at times punished—for using it. Families were pushed to abandon traditional Khmer names in favor of Thai ones. Gradually, the state promoted a single, standardized Thai identity as the only socially acceptable path.

These policies had profound consequences. They erased Khmer identity from public view, stripping it of legitimacy and collective memory. At the same time, they folded Khmer-origin communities into the Thai national story, allowing the state to reframe Khmer cultural legacies as Thai creations.

The Reluctance to Claim Khmer Roots

The effects continue to echo. Many Thai-Khmer individuals today avoid speaking openly about their heritage—not out of shame, but because Khmer identity has long been positioned at the bottom of Thailand’s social hierarchy. Claiming Khmer roots can still expose people to prejudice, mistrust, or fewer economic opportunities.

 

For millions of Khmer descendants, presenting themselves as fully Thai has become a practical strategy for safety, equal treatment, and upward mobility. Their assimilation, in turn, has served political ends: it provides the Thai state with a convenient rationale to claim Khmer-origin temples, languages, and artistic traditions as part of Thailand’s rightful cultural inheritance.

Education further cemented this shift. Thai school curricula gradually recast Khmer influence as a small, peripheral contribution. Classical Thai art forms were taught as indigenous breakthroughs.

Khmer temples located within modern Thai borders were designated “Thai heritage sites.” The once-dominant Khmer Empire faded from the narrative, replaced by stories of Thai kingdoms that supposedly emerged independently as the region’s natural civilizational heirs.

None of this was an accidental misunderstanding of the past—it was an ideological project. The doctrine of Thainess required a history untainted by subordination, imitation, or foreign influence. Within that framework, Khmer history could be acknowledged only superficially—and never in ways that challenged the supremacy of Thai identity.

The Civilizational Landscape Before the Rise of Thai Kingdoms

Understanding today’s Khmer–Thai debates requires grounding the discussion in chronology. Long before the first Tai polities appeared, mainland Southeast Asia was organized around the Khmer Empire.

From the ninth to the fifteenth century, Angkor stood as the region’s unrivaled center of governance, hydraulic engineering, and architectural ambition. Its cities ranked among the largest in the world, and its monuments—Angkor Wat, Angkor Thom, Banteay Srei, Phimai, and Phanom Rung—embodied unmatched mastery of stone, cosmology, and narrative artistry.

These achievements shaped vast areas that now lie inside Thailand. Northeastern Thailand (Isan), parts of the central plains, and the Lopburi basin were not marginal outposts—they were essential territories of the Angkorian world.

Khmer inscriptions, temples, reservoirs, roads, and fortified towns formed a dense civilizational landscape that predated Thai kingdoms by centuries. When modern Thailand labels sites like Phanom Rung or Phimai as “Thai historical parks,” it projects present-day borders onto a past that operated under entirely different cultural and political realities. These structures were not built by Thai states; they were constructed under Khmer rule at the height of Angkor’s power.

The first widely recognized Thai kingdom, Sukhothai, emerged only in the mid-13th century—long after Khmer influence had shaped the region’s political and artistic foundations.

Sukhothai’s rulers did not invent their own cultural system from scratch; they inherited and adapted models already refined by their Khmer predecessors. Even the Thai writing system, often celebrated as a marker of civilizational independence, draws directly from Old Khmer script. Early inscriptions, including the famed Ram Khamhaeng stele, clearly reflect Khmer structural and stylistic influence.

This is the uncomfortable historical reality that Thai nationalism has struggled to accept: the core elements of Thai high culture were built upon foundations laid by the Khmer Empire.

A pluralistic, historically confident society could acknowledge this without fear. But modern Thailand has anchored its identity in a very different narrative—one that depends on the notion of an unbroken, autonomous civilizational lineage.

Chhay Bora is Strategic Advisor, and Government Affairs & Public Policy Expert