Like in other Tai societies, the core social units of the Thái in Vietnam were the village (ban) and the chiefdom (mueang, Vietnamese: mường), each consisting of several villages and ruled by a Chao lord. The Thái mainly settled in valleys alongside the course of rivers and cultivate rice. A number of these mueang in the region grouped together and formed a long-term alliance, called Sip Song Chau Tai (Twelve Lands of Thai). This federation of Sip Song Chau Tai maintained political autonomy and had tributary relationship with the regional powers, such as China, Lan Xang, Siam and the dynasties of Vietnam.
