Prince of Yan
Zhu Di, the Prince of Yan, was preparing for his own uprising against the emperor and considered it a major point to neutralize Zhu Quan, a talented leader of well-trained troops located behind his lines. Taking advantage of Wu Gao's attack on Yongping near modern Shanhaiguan, the Prince of Yan after crushing Wu Gao's force rode hastily to Daning and feigned defeat and distress. After several days, his forces were in position and successfully captured Zhu Quan as he was seeing his brother off. The official history of the Ming records Daning's evacuation, with Zhu Quan's harem and courtiers removed to Songtingguan and the prince himself kept in the Yan capital at Beiping, but passes over Zhu Di's setting of the entire city to the torch and the destruction of Zhu Quan's extensive library.