Thailand (previously known as Siam) has been populated ever since the dawn of civilization in Asia. There are conflicting opinions of the origins of the Thais. It presumed that about 4,500 years. Thais originated in northwestern Szechuan in China and later migrated down to Thailand along the southern part of China. They split into two main groups. One settled down in the North and became the kingdom of "Lanna" and the other one is in further south, which afterward was defeated by the Khmers and became the kingdom of "Sukhothai".
The Origin of Thais