Battle of Bang Bo (Zhennan Pass)

Battle of Zhennan Pass
Part of the Sino-French War
Chinese fortifications at Zhennan Pass.
Date March 23 1885 Location Lang Son, Vietnam Result Chinese victory
Belligerents
France	China Black Flag Army
Commanders and leaders
Francois Oscar de Negrier	Feng Zicai

The Battle of Zhennan Pass (Chinese:鎮南關之役), normally referred to as Bang Bo in European sources, was an important Chinese victory during the Sino-French War. The battle, fought on 23 and 24 March 1885 on the Tonkin-Guangxi border, saw the defeat of 1,600 soldiers of General François de Négrier's 2nd Brigade of the Tonkin Expeditionary Corps by a Chinese army of 32,000 men under the command of the Guangxi military commissioner Pan Dingxin. The battle set the scene for the French retreat from Lang Son on 28 March and the conclusion of the Sino-French War in early April in circumstances of considerable embarrassment for France.

The political repercussions of the defeat, which resulted in the fall of Jules Ferry's government on 31 March 1885, were considerable. The ignominious end to the Sino-French War temporarily checked French domestic fervor for colonial expansion and culminated in the 'Tonkin Debate' of December 1885, in which the Chamber of Deputies voted to sustain the French commitment in Tonkin by the narrowest of margins.

The Tonkin military stalemate, March 1885

On 17 February 1885 General Louis Brière de l'Isle, the general-in-chief of the Tonkin Expeditionary Corps, left Lang Son with Lieutenant-Colonel Laurent Giovanninelli's 1st Brigade to relieve the Siege of Tuyen Quang. On 3 March, at the Battle of Hoa Moc, Giovanninelli's men broke through a formidable Chinese blocking position and relieved the siege. Before his departure Brière de l'Isle ordered General François de Négrier, who remained at Lang Son with the 2nd Brigade, to press on towards the Chinese border and expel the battered remnants of the Guangxi Army from Tonkinese soil. After resupplying the 2nd Brigade with food and ammunition, de Négrier defeated the Guangxi Army at Dong Dang on 23 February and cleared it from Tonkinese territory. For good measure, the French crossed briefly into Guangxi province and blew up the 'Gate of China', an elaborate Chinese customs building on the Tonkin-Guangxi border. They were not strong enough to exploit this victory, however, and the 2nd Brigade returned to Langson at the end of February.

By early March, in the wake of the French victories at Hoa Moc and Dong Dang, the military situation in Tonkin had reached a temporary stalemate. Giovanninelli's 1st Brigade faced Tang Qingsong's Yunnan Army around Hung Hoa and Tuyen Quang, while de Négrier's 2nd Brigade at Lang Son faced Pan Dingxin's Guangxi Army. Neither Chinese army had any realistic prospect of launching an offensive for several weeks, while the two French brigades that had jointly captured Lang Son in February were not strong enough to inflict a decisive defeat on either Chinese army separately. Brière de l'Isle and de Négrier examined the possibility of crossing into Guangxi with the 2nd Brigade to capture the major Chinese military depot at Longzhou, but on 17 March Brière de l'Isle advised the army ministry in Paris that such an operation was beyond their strength. Substantial French reinforcements reached Tonkin in the middle of March, giving Brière de l'Isle a brief opportunity to break the stalemate. He moved the bulk of the reinforcements to Hung Hoa to reinforce the 1st Brigade, intending to attack the Yunnan Army and drive it back beyond Yen Bay. While he and Giovanninelli drew up plans for a western offensive, he ordered de Négrier to hold his positions at Lang Son.

Meanwhile, behind the Chinese border, the Guangxi Army was also building up its strength. The French, whose Vietnamese spies in Lung-chou had been conscientiously counting the company flags of every Chinese battalion that passed through the town, estimated on 17 March that they were facing a Chinese force of between 40,000 and 50,000 men. This was probably an exaggeration. Most of the Chinese commands were understrength, and a reputable Chinese scholar has recently estimated the strength of the Guangxi Army at the Battle of Zhennan Pass at 32,000 men.

By the middle of March nine separate Chinese military commands were massed close up to the Tonkinese border around the enormous entrenched camps of Yen Cua Ai and Bang Bo. There were six main Chinese concentrations. The entrenched camp of Yen Cua Ai was held by ten battalions under the command of Feng Zicai (馮子材) and a slightly smaller force under the command of Wang Xiaochi (王孝祺). These two commands numbered perhaps 7,500 men in all. Two to three kilometres behind Yen Cua Ai, around the village of Mufu, lay the commands of Su Yuanchun (蘇元春) and Chen Jia (陳嘉), perhaps 7,000 men in all. Fifteen kilometres behind Mufu the commands of Jiang Zonghan (蔣宗漢) and Fang Yusheng (方友升), also 7,000 strong, were deployed around the village of Pingxiang (known to the French from its Vietnamese pronunciation as Binh Thuong). The commander of the Guangxi Army, Pan Dingxin (潘鼎新), lay at Haicun, 30 kilometres behind Mufu, with 3,500 men. Fifty kilometres to the west of Zhennanguan, 3,500 men under the command of Wei Gang (魏綱) were deployed around the village of Aiwa. Finally, fifteen kilometres to the east of Zhennanguan, just inside Tonkin, Wang Debang (王德榜) occupied the village of Cua Ai with 3,500 men.

On 22 March Chinese forces under the command of Feng Jicai raided the French forward post at Dong Dang, a few kilometres north of Lang Son. The French post, under the command of Lieutenant-Colonel Paul-Gustave Herbinger, was held by chef de battalion Diguet's 2nd Foreign Legion Battalion, and the legionnaires repelled the Chinese assault without difficulty. De Négrier decided to hit back by advancing across the frontier and attacking the Guangxi Army in its entrenchments at Bang Bo and Yen Cua Ai, near the frontier pass of Zhennanguan.

The battle of Zhennan Pass, 23 and 24 March 1885

Combat at Zhennan Pass.

On 23 and 24 March the 2nd Brigade, only 1,500 men strong, fought a fierce action with the Guangxi Army near Zhennanguan. This engagement, known as the Battle of Zhennan Pass in China, is normally called Bang Bo in European sources, after the name of a village in the centre of the Chinese position where the fighting was fiercest. The French took a number of outworks on 23 March, but failed to take the main Chinese positions on 24 March and were fiercely counterattacked in their turn. Although the French made a fighting withdrawal and prevented the Chinese from piercing their line, casualties in the 2nd Brigade were relatively heavy (70 dead and 188 wounded) and there were ominous scenes of disorder as the defeated French regrouped after the battle. As the brigade's morale was precarious and ammunition was running short, de Négrier decided to fall back to Lang Son.

The battle of Ky Lua, 28 March 1885

The Chinese advanced slowly in pursuit, and on 28 March de Négrier fought a battle at Ky Lua in defence of Lang Son. Rested, recovered and fighting behind breastworks, the French successfully held their positions and inflicted crippling casualties on the Guangxi Army, amply avenging the defeat at Bang Bo. French casualties at Ky Lua were 7 men killed and 38 wounded. The Chinese left 1,200 corpses on the battlefield, and a further 6,000 Chinese soldiers may have been wounded. The battle of Ky Lua gave a grim foretaste of the horrors of warfare on the Western Front thirty years later.

The French had won a stunning victory, and if de Négrier had remained in command the 2nd Brigade would probably have chased the Guangxi Army back across the Chinese border. But towards the end of the battle de Négrier was seriously wounded in the chest while scouting the Chinese positions. He was forced to hand over command to his senior regimental commander, Lieutenant-Colonel Paul-Gustave Herbinger. Herbinger was a noted military theoretician who had won a respectable battlefield reputation during the Franco-Prussian War, but was quite out of his depth as a field commander in Tonkin. Several French officers had already commented scathingly on his performance during the Lang Son campaign and at Bang Bo, where he had badly bungled an attack on the Chinese positions.

The retreat from Lang Son, 28 March to 1 April 1885

Upon assuming command of the brigade, Herbinger panicked. Despite the evidence that the Chinese had been decisively defeated and were streaming back in disarray towards the Chinese frontier, he convinced himself that they were preparing to encircle Lang Son and cut his supply line. Disregarding the appalled protests of some of his officers, he ordered the 2nd Brigade to abandon Langson on the evening of 28 March and retreat to Chu. The French retreat was conducted without loss and with little interference from the Chinese, but Herbinger set an unnecessarily punishing pace and insisted on abandoning considerable quantities of food, ammunition and equipment. When the 2nd Brigade eventually rallied at Chu, its soldiers were exhausted and demoralised. Meanwhile the Chinese general Pan Dingxin (潘鼎新), informed by sympathisers in Lang Son that the French were in full retreat, promptly turned his battered army around and reoccupied Lang Son on 30 March. The Chinese were in no condition to pursue the French to Chu, and contented themselves with a limited advance to Dong Song.

Lang Son: l'Affaire Tonkin

Herbinger's decision to abandon Lang Son, surrendering nearly all French gains made during the 1885 campaign, convinced the commander of the expeditionary corps, Louis Briere de l'Isle, that the Delta was in jeopardy. His dispatches to Paris caused a political panic. Ferry was attacked in the streets, and his political opponents called assembly meetings to denounce both Ferry and the entire colonial project.

While Ferry tried to begin secret negotiaions with the Chinese, he presented an emergency draft of some 200 million francs for a rescue force to be sent to Tonkin. With Georges Clemenceau leading the parliamentary opposition, the National Assembly balked, bringing down the Ferry government on 28 March 1885.

Within a few days, Briere de l'Isle realized the situation was less grave than it had initially appeared, but it was several weeks before the situation was clear to Paris. The new French government, still fearing their forces would be overrun, gave orders for an evacuation of French troops from the Tonkin region. although this was never carried out.

The consequences to colonial policy stretched beyond Tonkin, or even Paris. Writes one historian of French colonialism in Madagascar, "There was a general desire to have done with other colonial expeditions still in progress."

Flag of the "Black Flag Army", captured by the French Army in Tonkin in 1885. Musée de l'Armée, Paris.

Aftermath

Indochina

Despite the retreat from Lang Son, France's overall success on the ground, and above all its naval victories, led the Chinese mandarin Li Hongzhang to sign a treaty ending the war on June 9 1885, with China acknowledging the Treaty of Hué and relinquishing its suzerainty over the Empire of Annam. Annam and Tonkin were incorporated into French Indochina as protectorates soon thereafter. The controversial treaty caused heavy criticism to be levelled on Li Hongzhang and the Qing government, and created nationalistic sentiment throughout China. The war was a significant step in the decline of the Qing empire, due both to the humiliation of the loss and the destruction of the Southern fleet. It also demonstrated the flaws in the late-Qing national defense system of independent regional armies, as northern Chinese forces, both ground and naval, declined to participate in the campaign.

French reaction

The battle's principal effect in France, aside from the significant gain in imperial territory, was to bring down the long-running Ferry ministry. Within a year the government of his successor, Brisson, also fell over the Tonkin budget of November 1885. Ferry would never again serve as premier, and became a figure of popular scorn. The defeat, which the French called the "Tonkin affair", was a major political scandal for the proponents for French colonial expansion that had begun with the ascencion of Leon Gambetta. It was not until the early 1890s that French colonial party regained domestic political support.

See also

• Imperialism in Asia
• French colonial empires
• Jules Ferry