Police three yuan, which three yuan are you talking about?

The police "Sanyuan" was originally from Yizhou, and later moved to Chang 'anli, Jingzhou Public Security County. Yuan Zongdao (1560- 1600), whose real name is Boxiu, was a scholar in the 14th year of Wanli in the Ming Dynasty, and has been editing and editing for imperial academy, the right bastard of Chunfang. Yuan Hongdao (1568- 16 10), a native of Langzhong, was a scholar for twenty years in Wanli, and served as a magistrate of Wuxian county and chief of the seal inspection department of the official department. Yuan Zhongdao (1570- 1626), a minor figure, was a scholar in the forty-fourth year of Wanli, and was a professor in Huizhou and a doctor in Nanjing. The three brothers, known as "Sanyuan", are all famous literary innovators-leaders of the "Public Security School". Among them, Yuan Hongdao has the greatest achievement and the most famous reputation.