The Cau Bong Source (Phuong Kieu) is a "special administrative unit" and major Source in the source system in Vietnam between 17th and 19th centuries. However, the number of research on this source are limited and even contain confusing information. Based on analyzing and comparing many different sources and results of field surveys, this article focuses on clarifying: the duration of existence, reason for establishment, and localities of the headquarters of the Cau Bong source; policies of managing ethnic minorities, managing trading activities, tax collection and ensuring security in mountainous areas, merchant forces, commercial products and economic functions of the Cau Bong source; the relationship between the Cau Bong source and the Tay Son uprising. Thus, this paper aims to contribute to a deeper identification of sources in Vietnam in the 17th and 19th centuries.
