Fan Chengda (1126-1193) was a high-ranking Chinese government official in Guangxi, an experienced traveler, a keen observer, and a gifted writer. His observations on a wide range of subjects are always interesting and revealing, and constitute an important contribution to the literature on Song dynasty China’s frontier peoples. Originally written in direct, unadorned, and allusion-free classical Chinese prose, the complete and annotated English translation of Treatises of the Supervisor and Guardian of the Cinnamon Sea (Guihai yuheng zhi) captures its charm and significance.