Etymology

Through the centuries, Vietnam has been called by many different names: Văn Lang during the Hùng Vương Dynasty, Âu Lạc during the An Dương Vương dynasty, Van Xuan during the Anterior Lý Dynasty, Đại Cồ Việt during the Đinh dynasty and Anterior Lê Dynasty. Starting in 1054, Vietnam was called Đại Việt (Great Viet). During the Hồ Dynasty, Vietnam was called Đại Ngu. Then, in 1804, King Gia Long planned to use the name of Nam Việt for Vietnam then changed it to Việt Nam. In English, the two syllables were written into one: Vietnam. From 1839 to 1945, Emperor Minh Mạng renamed Việt Nam to Đại Nam (literally "Great South").

The name Việt Nam had been used for this country before it became the official name in "Dư địa chí" of Nguyễn Trãi written in 1435 and perhaps even before. "Việt" is the name of the largest ethnic group in Vietnam: the Kinh (người Kinh) and "Nam" means "the South", affirming Vietnam's sovereignty from China (usually called "North country" by the Vietnamese).

Source by Wikipedia