The Việt Nam is a variation of Nam Việt (Southern Việt), a name that can be traced back to the Triệu Dynasty (2nd century BC). The word "Việt" originated as a shortened form of Bách Việt, a word used to refer to various peoples who lived in what is now southern China in ancient times. The word "Việt Nam", with the syllables in the modern order, first appears in the 16th century in a poem by Nguyễn Bỉnh Khiêm. "Annam", which originated as a Chinese name in the seventh century, was the common name of the country during the colonial period. Nationalist writer Phan Bội Châu revived the name "Vietnam" in the early 20th century. When rival communist and anti-communist governments were set up in 1945, both immediately adopted this as the country's official name. In English, the two syllables are usually combined into one word, "Vietnam." However, "Viet Nam" was once common usage and is still used by the United Nations and by the Vietnamese government.