尊室說
After killing Francis Garnier in 1873 when he attacked Hanoi, Liu Yongfu received a promotion to vice military commander in Vietnamese bureaucracy. Later in 1874, Hoàng Kế Viêm was appointed as governor-general of Sơn-Hưng-Tuyên and Tôn Thất Thuyết served as governor of Sơn Tây and consoler for military affairs. These two officials, together with Liu Yongfu, continued their struggle with Pan Lunsi and Yellow Flags which was the prior concern of Huế court. In early 1874, they sent out armies to chase after Yellow Flags from Tuyên Quang. In September, Pan Lunsi offered his surrender letter to Hoàng Kế Viêm, but the court still showed no interest and ordered governor of Hừng Hoa to demand Black Flags to capture Pan Lunsi. In March 1875, Huế court, refusing China’s assistance in the war with Yellow Flags before, accepted Chinese help, appointed Tôn Thất Thuyết to cooperate with Qing military against Yellow Flags. Qing’s army, led by Li Yangcai and Liu Yucheng, flushed most Yellow Flags out of Thái Nguyên, while Black Flags and Vietnamese military waited them in Hà Dương, the old base of Yellow Flags. The war ended with Pan Lunsi’s mutilation and dismemberment. In 1878, Liu Yongfu began to receive monthly salary and supplies from Huế court as reward to his victory over the Yellow Flags. But not all the imperial officials accepted the Black Flags. Hoàng Kế Viêm, as the liaison between the court and Black Flags, encouraged Liu Yongfu and his men to cultivate land around Lào Cai so that he could not only mollify the critics towards Black Flags from imperial officials but also control the imperial bandit by binding them in one location. But his plan failed for Liu Yongfu had no interest in land cultivation or leaving Lào Cai. Later in March 1878, Black Flags conducted raids in Hưng Hóa province. At the same time, officials in Hanoi required a full report of Liu Yongfu’ actions through the court. Hoàng Kế Viêm promised to have a full investigation into Liu Yongfu, providing the account of his alleged crimes against Vietnamese authorities.