They are probably the most numerous and widely diffused Indo-Chinese race and occupy the valleys and plateau of the broad belt of mountainous country that leaves the Himalayas and trends Southeasterly between Burma proper on the west and China, Assam and Vietnam on the east, to the Gulf of Siam.
Tai are people of mainland Southeast Asia, including:
The Thai or Siamese (in central and southern Thailand),
The Lao (in Laos and northern Thailand),
The Shan (in northeast Myanmar @ Burma),
The Dai (in Yunnan province, China, Myanmar, Laos, northern Thailand and Vietnam) and The Tai (in northern Vietnam).