Black Flag Army

The Black Flag Army was a splinter remnant of a bandit and mercenary group recruited largely from soldiers of ethnic Zhuang background and former Taiping soldiers who crossed the border in 1865 from Guangxi, China into northern Vietnam, during the Nguyễn dynasty, and were hired and sponsored by Vietnamese authorities to fight against other bandits and rebels. Although brigands, they were known mainly for their fights against the invading French forces, who were then moving into Tonkin. The Black Flag Army is so named because of the preference of its commander, Liu Yongfu, for using black command flags.
The army was officially disbanded in 1885 as a result of the Treaty of Tientsin between France and China. However, remnants of the army continued to wage a guerrilla war against French colonial authorities for years. With the sanction of both Vietnamese and Chinese authorities, the Black Flags joined the Vietnamese irregular forces, stemming French encroachment beyond the Red River Delta.

The rise and fall of the Black Flag Army

In 1857, Liu Yongfu, a Hakka soldier of fortune, commanded a group of about 200 men within a larger Highwayman group in Guangxi province headed by Huang Sihong. He allied with the Taiping forces in the region. He defected with his men to the band of Wu Yuanqing under his own black flag. Liu organized a ceremony reminiscent of the tiandihui rituals and what became known as the Black Flag Army was born. The "army" operated as an independent unit under Wu Yuanqing and under his son and successor, Wu Yazhong or Wu Hezhong. Although not part of the Taiping forces, both Wu Yuanqing and Wu Yazhong laid claim to be Taiping "princes".
After Qing forces crushed the Taiping Rebellion in 1864 in Nanking, the Qing army proceeded to destroy systematically the many armed bands of their south-eastern provinces. Hotly pursued, the desperate Wu Yazhong, with Liu and his Black Flag Army who had also taken over the former Taiping army in the region, crossed into Upper Tonkin in 1865, looting and pillaging villages on their way.
The Black Flags demonstrated their usefulness to the Vietnamese court by helping the suppression of the indigenous Hmong tribes populating the mountainous terrain between the Red and Black Rivers, and for this Liu was rewarded with an official military title.
Secured with the backing of the Vietnamese court, Liu Yongfu established a profitable extortion network along the course of the Red River, "taxing" river commerce between Sơn Tây and Lào Cai at a rate of 10%. He and the Black Flag Army also took over mines in the region and created a protection system, as well as robbing villages in the countryside. The profits accrued from this venture were so great that Liu's army swelled in numbers in the 1870s, attracting to its ranks adventurers from all over the world. Although most of the Black Flag soldiers were Chinese, the junior officers included American and European soldiers of fortune, some of whom had seen action in the Taiping Rebellion. Liu used their expertise to transform the Black Flag Army into a formidable fighting force. Under his command in Tonkin he had 7,000 soldiers from Guangdong and Guangxi.
The harassment of European vessels trading on the Red River triggered the dispatch of the French expeditionary force to Tonkin under Commandant Henri Rivière in 1882. The resulting clashes between the French and the Black Flag Army escalated, resulting eventually in the Sino-French War. The Black Flags assisted the Chinese forces during this war, best known for the fierce Siege of Tuyên Quang when the joint Black Flag-Chinese armies besieged a battalion of the French Foreign Legion defending the citadel. The Black Flag Army formally disbanded at the end of the Sino-French War, though many of its members continued to harass the French for years afterwards as freelance bandits.
Remarkably, Liu Yongfu revived the Black Flag Army again in 1895 in response to the Japanese invasion of Taiwan. Liu Yongfu crossed to Taiwan at the appeal of his old friend Tang Jingsong, the island's former governor-general and now president of the short-lived Republic of Formosa. Liu was to command the Formosan resistance forces against the Japanese. Liu took a number of aging Black Flag veterans back into service to join the fight against the Japanese, but the reconstituted Black Flag Army was swept aside with ease by the Japanese Imperial Guards Division. Liu himself was obliged to disguise himself as an old woman to escape capture.
An entry on the Black Flags in "Appletons' Annual Cyclopaedia and Register of Important Events, Volume 8; Volume 23":

The Black Flag Army in action

Killing of Lieutenant Francis Garnier, December 1873

In 1873, the Vietnamese government enlisted the help of the Black Flag Army to face an attempt to conquer Tonkin by French naval lieutenant Francis Garnier, who was acting without orders after having been sent there on a diplomatic mission. On 21 December 1873, Liu Yongfu and around 600 Black Flags, marching beneath an enormous black banner, approached the west gate of the Hanoi Citadel. A large Vietnamese army followed in their wake. Garnier ordered the shelling of the Black Flags with a field piece mounted above the gate and, when they were repulsed, led a party of 18 French marine infantrymen out of the gate in pursuit. Garnier and three of his men charged uphill in a bayonet attack on a party of Black Flags but was speared to death after stumbling in a watercourse. The youthful enseigne de vaisseau Adrien-Paul Balny d’Avricourt led a similar small column to reinforce Garnier but was also killed in front of his men. Three other French soldiers were also killed in these sorties, and the others fled back to the citadel after their officers fell.
Despite Garnier's death, the attempt to retake Hanoi had failed and the French remained in control of the greater part of the Red River Delta. However, the French government disapproved the unauthorized conquest and lieutenant Paul Philastre was sent to remove Garnier's men from the cities they occupied and repatriate them back to Saigon in February 1874.
During this period, the Black Flag Army also successfully fought other groups of bandits and mercenaries, such as the White Flag Army and Yellow Flag Army.

Defeat of Henri Rivière's invasion of Tonkin, May 1883

Ten years later, with France again pushing into Tonkin, undeclared hostilities broke out in 1883 and the first half of 1884 as a prelude to the Sino-French War. The Black Flags fought several engagements against French forces in Tonkin. The first major clash was at the Battle of Paper Bridge, in which the French naval captain Henri Rivière was ambushed and killed. It was a swift and striking victory for the Black Flag Army.

Indecisive clashes, summer 1883

In the Battle of Phủ Hoài, the Black Flag Army successfully defended its positions against a French attack launched by General Alexandre-Eugène Bouët, though it took considerably higher casualties than the French. In the Battle of Palan the Black Flags did less well, being driven from a key position on the River Đáy.

Disaster at Sơn Tây, December 1883

In December 1883, the Black Flag Army suffered a major defeat at the hands of Admiral Amédée Courbet in the Sơn Tây Campaign. Despite fighting with fanatical courage in the engagements at Phù Sa on 14 December and Sơn Tây on 16 December, the Black Flags were unable to prevent the French from storming Sơn Tây. Even with large Chinese and Vietnamese regular contingents at Sơn Tây, the Black Flag Army bore the brunt of the fighting, and took very heavy casualties. In the opinion of the British observer William Mesny, a senior officer in the Chinese army, the fighting at Sơn Tây broke the power of the Black Flag Army, though the stubborn defence put up by the Black Flags in the Battle of Hòa Mộc fifteen months later does not bear out this assessment.

Loss of Hưng Hóa, April 1884

The Black Flag Army took no part in the Bắc Ninh Campaign. After the French capture of Bac Ninh, the Black Flags retreated to Hưng Hóa. In April 1884 the French advanced on Hưng Hóa with both brigades of the Tonkin Expeditionary Corps. The Black Flags had constructed a series of fortifications around the town, but General Charles-Théodore Millot, the French commander-in-chief, took it without a single French casualty. While General François de Négrier's 2nd Brigade pinned the Black Flags frontally from the east and subjected Hung Hoa to a ferocious artillery bombardment from the Trung Xa heights, General Louis Brière de l'Isle's 1st Brigade made a flank march to the south to cut Liu's line of retreat. On the evening of 11 April, seeing Brière de l'Isle's Turcos and marine infantry emerging behind their flank at Xuân Đông, the Black Flags evacuated Hưng Hóa before they were trapped inside it. They set alight the remaining buildings before they left, and on the following morning the French found the town completely abandoned.

Loss of Tuyen Quang, June 1884

The Black Flag Army retreated up the Red River to Thanh Quan, only a few days march from the frontier town of Lào Cai. Several hundred Black Flag soldiers, demoralised by the ease with which Courbet and Millot had defeated the Black Flag Army, surrendered to the French in the summer of 1884. One of Millot's final achievements was to advance up the Lô River and throw the Black Flag Army out of Tuyên Quang in the first week of June, again without a single French casualty. If the French had seriously pursued Liu Yongfu after the capture of Tuyên Quang, the Black Flags would probably have been driven from Tonkin there and then. But French attention was diverted by the sudden crisis with China provoked by the Bắc Lệ ambush, and during the eventful summer of 1884 the Black Flags were left to lick their wounds.

Alliance with the Chinese, September 1884 to April 1885

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 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 Hưng Hóa and the isolated French posts of Phủ Doãn and Tuyên Quang during the autumn of 1884.