[5] With the fall of the Angkor, the Khmers of the Isan region were subject to increasing Thai influence.

In the 18th century, the Thai kingdom officially annexed the former Cambodian province of Surin.

The Khmer residents became de facto subjects of the Thai monarchy and a long process of gradual cultural assimilation began.

Few Northern Khmers are able to read or write their native language,[15] since teaching in public schools is exclusively in Thai.

[17] In the past two decades, there has been state-directed revitalization of 'local' cultures in Thailand, including of Khmer culture, which has been challenged for adopting a state narrative and insufficiently empowering the Northern Khmer themselves.