*Origin and development**
- The system of comforting the army that began in the Spring and Autumn Period when Gou Jian, King of Yue, "migrated widows to Dushan Mountain to travel as sergeants" ("Yue Jueshu")
- Formal institutionalization in the Han Dynasty: "There were no prostitutes in ancient times, but camp prostitutes were established in Wuhan, Han Dynasty" (quoted in the Notes of "Han Shu")
- It became a punishment in the Ming Dynasty: the female relatives of Emperor Jianwen's loyal ministers were "reduced to prostitutes in camps and were ravaged by multiple soldiers every day" ("Unofficial History of China")
