The Tây Bắc (literally meaning “Northwest“) was a region in northwest Vietnam bordered by northern Laos and southern China. It consisted of the provinces Lai Châu, Sơn La and Nghĩa Lộ. As part of the strategically important Việt Bắc region that served as an old administrative unit of the Democratic Republic of Vietnam (DRV) and the Việt Minh’s base during the First Indochina War (1946–1954), Tây Bắc hosted important battles such as the Battle of Điện Biên Phủ and the Battle of Nà Sản. In 1955, the Tây Bắc was renamed as the Thai-Meo Autonomous Region (1955-1962) in an effort to establish autonomous regions for ethnic groups in Vietnam. It was then renamed Northwest Autonomous Region (1962-1975). The Tây Bắc Autonomous Regio existed until 27 December 1975 when it was dissolved along with the Việt Bắc Autonomous Region.