黒旗軍
The fortunes of the Black Flag Army were transformed by the outbreak of the Sino-French War in August 1884. The Empress Dowager Cixi responded to the news of the destruction of China's Fujian Fleet at the Battle of Fuzhou (23 August 1884) by ordering her generals to invade Tonkin to throw the French out of Hanoi. Tang Jingsong, the commander of the Yunnan Army, knew that Liu's services would be invaluable in the war with France, and Liu agreed to take part with the Black Flag Army in the forthcoming campaign. The Black Flags helped the Chinese forces put pressure on Hung Hoa and the isolated French posts of Phu Doan and Tuyen Quang during the autumn of 1884.