 
Part of the Sino-French War in Vietnam
The Battle of Đồng Đăng (23 February 1885) was an important French victory during the Sino-French War. It is named after the town of Đồng Đăng, then in northern Tonkin, close to the border between China and Vietnam.
Background.
The battle was fought as a pendant to the Lạng Sơn Campaign (3 to 13 February 1885), in which the French captured the Guangxi Army's base at Lạng Sơn.
On 16 February General Louis Brière de l'Isle, the commander of the Tonkin Expeditionary Corps, left Lạng Sơn with Giovanninelli's 1st Brigade to relieve the Siege of Tuyên Quang. Before his departure, he ordered General Oscar de Négrier, who would remain at Lạng Sơn 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 advanced to attack the Guangxi Army at Đồng Đăng.
French forces at Đồng Đăng.
De Négrier's 2nd Brigade numbered just under 2,900 men in February 1885. The brigade's order of battle was as follows:
De Négrier advanced on Đồng Đăng with Herbinger's three line battalions, the two Foreign Legion battalions, a company of Tonkinese riflemen and Roperh and de Saxcé's batteries. Servière's 2nd African Battalion was left to guard Lạng Sơn and the brigade's supply line back to Chu. Martin's battery also remained at Lạng Sơn.
Chinese positions.
The Chinese had established an extremely strong position, centred on a limestone plateau which rose just to the west of the Mandarin Road and ran due north from Đồng Đăng to the Gate of China and beyond into China itself. This massif overlooked Đồng Đăng and the approaches to the Gate of China, and presented a sheer cliff face towards the southeast. It could only be climbed on its western side, and the Chinese had established a sheltered artillery position on its summit, just behind Đồng Đăng, commanding the steep western slopes that an attacker would have to scale. A number of infantry camps and several other artillery emplacements had been built on the summit.
The left of the Chinese position lay along the hills directly to the east of the Mandarin Road, which were covered by the elevated infantry and artillery positions on the limestone massif. These positions were quite secure against a frontal attack as long as the massif itself remained in Chinese hands. To reach a position from which they could assault the limestone massif the French would first have to take Đồng Đăng, which lay directly in their way. The Chinese had deployed their right wing in and around Đồng Đăng. The small low-lying town was the weakest point in the Chinese position, but the Chinese had done what they could to strengthen it by building three strong forts on the hills to its west, overlooking the villages of Dong Tien and Pho Bu and the That Ke valley. These strongpoints, the ‘Western Forts’, were linked by a defensive line which contained Đồng Đăng itself. The Chinese could also rely on the Đồng Đăng stream, a fast-flowing arroyo which ran across the entire front of their line, to act as a moat for their defences and slow down any French attack.
The battle of Đồng Đăng, 23 February 1885.
The French attack column left Lạng Sơn at 8:00 am on 23 February and followed the Mandarin Road towards Đồng Đăng. The road threaded its way along the defiles separating the steep mountains, passing through a number of small, abandoned villages. To guard against a possible Chinese surprise attack, "chef de bataillon" Tonnot led the way with an unusually strong advance guard—Diguet's Legion battalion, de Saxcé's battery, the Tonkinese skirmishers and the cavalry. Herbinger followed on behind with the rest of the infantry and Roperh's battery. The 143rd Battalion was split into individual companies for the day's operations. One company marched with the main body, a second formed the rearguard, and the remaining two were detached as escorts for the two artillery batteries.
At 9:30 am the French vanguard entered the village of Tham Lon and discovered some unoccupied Chinese forts above the nearby hamlet of Ban Vinh. Shortly afterwards it was engaged by a group of Chinese skirmishers, who began firing to warn their comrades of the French approach. Their fire was not dangerous and the French continued to press on, looking for ground where they could deploy into a line of battle. Tonnot deployed a section of de Saxcé's battery to give covering fire if necessary, but the Chinese fell back and occupied a rise at a right angle to the road. They were joined by other troops, and began to fire at the head of the French column.
The French vanguard now began to deploy into the hills on both sides of the Mandarin Road to face the Chinese skirmishers. De Négrier, attracted by the sound of the firing, joined Tonnot at the head of the French column. to the north of Ban Vinh there was a tall hill which looked as though it would offer a good view of the Đồng Đăng valley, where the Chinese were presumably entrenched. This seemed to be the best position available for the French artillery, and de Négrier sent forward Bérard's Legion company to secure it. A party of Chinese skirmishers was occupying the hill, but the legionnaires drove them from it with little difficulty. De Négrier sent a galloper back to the column's main body with orders for Roperh to deploy his battery on the summit of the hill, now christened by the French 'Bérard Mound'. While Roperh struggled to get his guns up to the summit of Bérard Mound the brigade's vanguard fanned out on both sides of the Mandarin Road. Captain Geil's Tonkinese riflemen deployed just to the right of the road, linking up with Bérard's company, while the other three companies of Diguet's battalion deployed to the left.
Chinese spoiling attack.
Tonnot's vanguard had won enough space for the brigade's main body to close up and deploy in its turn. De Négrier sent half of his troops to its left and the other half to its right. Diguet's legionnaires and Geil's Tonkinese now found themselves holding the centre of the French line. De Négrier had already decided to throw his right wing forward, in order to secure Bérard Mound for his artillery, and he now decided to refuse his left wing, deploying the brigade in a diagonal line of three mutually-supporting echelons astride the Mandarin Road. But this deployment, in hilly terrain, was a necessarily slow business, and at around midday the Chinese attempted to envelop both French flanks, perhaps hoping to catch them unprepared.
The Chinese attack on the French left, where de Négrier had refused his line, had little chance of success. The French left wing was held by the 23rd Line Battalion, which was occupying a hill to the southwest of the Mandarin Road behind and to the left of Diguet's legionnaires. The attackers, who issued in large numbers from the Western Forts, attempted to advance up the valley towards Ban Vinh to engage the 23rd Battalion. They had more than to march, and before they had covered half this distance they came under fire from a section of French artillery and the three Legion companies deployed to the left of the Mandarin Road. It became clear that the attack was not going to succeed, and the Chinese fell back. The 23rd Battalion did not have to fire a shot in this action, and the Chinese made no further attempts to move against the French left.
By contrast, the Chinese attack on the right against Bérard Mound, occupied by Roperh's battery and its escorts and Bérard's Legion company, was pressed home vigorously. The Chinese infantry were in considerable strength, and on this occasion were adequately supported by their artillery, which began to engage Roperh's battery from its positions on the cliffs behind Đồng Đăng. The enemy gunners soon found the range and, uniquely during the Sino-French War, the French came under well-aimed artillery fire. Disconcerted by the speed and accuracy of the Chinese fire, Roperh's battery had to change position. De Négrier sent Commandant Schoeffer to Bérard Mound to reinforce its defenders with Lascombes and Gaucheron's companies from his own Legion battalion. Lascombes and Bérard then led their men in a counterattack against a hill overlooking the French position. Bérard was shot in the chest and seriously wounded during this counterattack, but Lieutenant de Féraudy immediately assumed command of his company and drove home the French charge. The Chinese fell back in disorder.
French attack on the Western Forts.
The French had defeated both Chinese flanking attacks. They could now consider taking the offensive themselves. De Négrier's plan was a simple and logical three-step operation. To win the battle, the French had to throw the Chinese off the limestone massif. To attack this position, they had first to take Đồng Đăng. To assault Đồng Đăng without suffering crippling casualties, they had to weaken its defences by reducing the Western Forts. The first step was therefore to capture the Western Forts.
De Négrier prepared the attack on the Western Forts with a lengthy artillery bombardment of the Chinese positions. De Saxcé and Jourdy's batteries first engaged the Chinese guns in their emplacements on the limestone massif, and by 1:00 pm had completely silenced them. The French batteries then turned their attention to the Chinese positions on the hills to the east of the Mandarin Road that ran back to the Chinese frontier. So far the French infantry on the right of de Négrier's line had shown no signs of advancing, and the Chinese defenders saw no reason to hold their ground under artillery fire. Unable to reply to the French guns, they evacuated their trenches on the forward slopes and fell back to more sheltered positions on the reverse slopes. Finally, the French guns swept the Chinese positions around the Western Forts.
Just before 3:00 pm, when he judged that the Chinese were sufficiently demoralised, de Négrier ordered Herbinger to capture the Western Forts with the 111th Line Battalion and the five closest companies of Diguet and Schoeffer's Legion battalions. The attack would be screened by Geil's Tonkinese. The Chinese did not attempt to hold the forts in the face of the French advance. Their right wing battalions abandoned their positions and began to retreat along the path to That Ke. Herbinger ordered Diguet's men to pursue the retreating Chinese for some distance and set up a blocking position astride the path. He then reorganised the rest of his troops for the next step in de Négrier's programme, the assault on Đồng Đăng.
Capture of Đồng Đăng by 111th Battalion.
Most of the houses in the southern part of the town had been set alight by the French artillery bombardment, and the position was now held only by small groups of Chinese skirmishers. Herbinger decided that the main assault on the town would be made by the 111th Battalion, screened by the Tonkinese and with Brunet and Michel's companies of Schoeffer's Legion battalion in support. The 111th had to advance across of open ground, under fire from both the Chinese on the summit of the limestone massif and from a group of Chinese skirmishers in Đồng Đăng itself. The French conscripts moved forward at a brisk trot and eventually reached the Đồng Đăng stream, from the outskirts of the town. Here they hesitated. Men began to fall to the enemy's fire. The company officers jumped into the stream to set an example, and waded through waist-high water to the other side. Once they clambered onto dry land the soldiers had only one thought: to reach the shelter of Đồng Đăng and escape from the plunging fire from the limestone massif. In complete disorder, running at full tilt to close the distance as quickly as possible, the young soldiers of the 111th Battalion charged wildly into the blazing town. The astonished company officers raced to place themselves at the front of this impromptu charge, waving their swords above their heads to spur on their men to yet greater efforts. The speed and fury of this improvised attack took the Chinese skirmishers completely by surprise. They tried to evacuate Đồng Đăng but were not fast enough. The soldiers of the 111th trapped laggards