In 1948, the French colonial administration declared the Tai Federation (, native name: Phen Din Tai, ; by that time consisting of 19 Tai states in then three Vietnamese provinces of Lai Châu, Sơn La and Phong Thổ) to be an independent component of the French Union.
The Tai Federation was however not only populated by Tai peoples, but also other "hill tribes" (montagnards), including Hmong, Yao, Yi (Lolo) and Khmu.