Origin of the Tai People 4―Ethnic Descent of the Tai-Kadai People describes the latest academic hypothesis on the ancient forefathers of the Tai people. Those ancient forebears, named pre-Austronesians, migrated from the area of the mid-Huang He Valley (or mid-Yellow River Valley) of modern northeastern China southward into the Yangtze River Delta of eastern China, and followed the coastal route to the Fujian coast of southeastern China.