In the first year of the Zhizhi era (1321), the second son of Emperor Wuzong (Külüg Khan), Prince Tugh Temür, was exiled to Ding’an, Hainan.

In his moment of despair and frustration, the prince came to know Qingmei, a servant girl in the household of Marshal Chen Qianheng from Nanlei Hamlet. She was versed in poetry, dancing, and singing, and was beguiling in both form and manner.

The two gradually developed feelings for each other, and the prince asked Qingmei to be his bride. Mindful of the vast difference in their social statuses, she politely refused.

Wang Guan, chief of Nanlei Hamlet and uncle to Qingmei, was moved by their plight and offered the prince 300 gold taels as a betrothal gift for Qingmei. The two were married and lived happily together.

However, this joy was cut short when the prince was recalled to the capital, Dadu, in the far north. On their return, Qingmei, unable to withstand the colder climes, sadly perished at an inn in Hangzhou. 

Years later, the prince, who was now the emperor, never forgot the kindness and joy he found in Ding’an. He elevated Wang Guan as prefect of Qiongzhou, moving the prefectural administration to Qiongya Township. He renamed the Qiongzhou Military and Civilian Pacification Department as the Qianning Military and Civil Pacification Department, and upgraded Ding’an County to Nanjian Prefecture, which fell under the jurisdiction of the Haibei Marshal’s mansion.