The area of present-day Surin has long history of human settlement which dates back to prehistoric times. Historically the region has been ruled by various powerful kingdoms including the Angkorian Khmer Empire, the Lao kingdom Lan Xang, and the Thai kingdom of Ayutthaya. Reflecting this history as part the greater geo-cultural area of Thailand known as Isan, Surin is ethnically diverse. The primary language is the Isan dialect of Lao. Speakers of Central Thai account for a small minority while nearly 50% of the population are ethnic Khmer. The remainder are speakers of various Lao languages and small tribal groups such as the Kuy and Nyah Kur.