A Laotian population has been present in the Isan region of Thailand since the 13th century, when the Lao kingdom of Lan Xang annexed the region following the Khmer Empire's downfall. The kingdom of Siam later took over the region in the early 1700s after Lan Xang's decline and the present boundaries between Laos and Thailand were established in 1907, with the region officially coming under Thai control.Laos under the French, U.S. Library of congress While this earlier group of Laotians share a very similar culture and speak a language mutually intelligible with Lao, they are often identified as a separate ethnic group due to Thaification policies as a result of the Thai government seeing strong Lao influence in the country as a threat to its power.
