Capture of Nam Định ( 1883 ) The Capture of Nam Dinh ( 27 March 1883 ) , a confrontation between the French and the Vietnamese , was one of the early engagements of the Tonkin campaign ( 1883 – 86 ) . In a brief campaign in the last week of March 1883 , Commandant Henri Rivière captured the citadel of Nam Dinh , the second - largest city in Tonkin , with a flotilla of gunboats and a battalion of marine infantry . Rivière ' s seizure of Nam Dinh marked a significant escalation of French ambitions in Tonkin , and had important consequences . China began to covertly support the Vietnamese government in its opposition to French colonization . Chinese involvement in Tonkin ultimately resulted in the nine - month Sino - French War ( August 1884 – April 1885 ) . Background . French intervention in northern Vietnam was precipitated by Commandant Henri Rivière , who was sent with a small French military force to Hanoi at the end of 1881 to investigate Vietnamese complaints against the activities of French merchants . In defiance of the instructions of his superiors , Rivière stormed the citadel of Hanoi on 25 April 1882 . Although Rivière subsequently returned the citadel to Vietnamese control , his recourse to force was greeted with alarm in both Vietnam and China . The Vietnamese government , unable to confront Rivière with its own ramshackle army , enlisted the help of Liu Yongfu , whose well - trained and seasoned Black Flag soldiers were to prove a thorn in the side of the French . The Vietnamese also bid for Chinese support . Vietnam had long been a vassal state of China , and China agreed to arm and support the Black Flags and to covertly oppose French operations in Tonkin . The Qing court also sent a strong signal to the French that China would not allow Tonkin to fall under French control . In the summer of 1882 troops of the Chinese Yunnan and Guangxi armies crossed the border into Tonkin , occupying Lang Son , Bac Ninh , Hung Hoa and other towns . The French minister to China , Frédéric Bourée , was so alarmed by the prospect of war with China that in November and December 1882 he negotiated a deal with the Chinese statesman Li Hongzhang to divide Tonkin into French and Chinese spheres of influence . Both negotiators were criticized for giving too much away , and the deal soon unravelled . It was never ratified in China , and in France Jules Ferry ' s incoming administration disavowed the agreement in March 1883 and recalled Bourée . Occupation of Hon Gai . In late February 1883 , the French forces in Hanoi were reinforced by a 500 - man battalion of marine infantry from France under the command of Lieutenant - Colonel Carreau , which more than doubled the force at Rivière ’ s disposal , was a parting gift from the bellicose Admiral Bernard Jauréguiberry , who had been replaced as navy minister on 29 January . Carreau ’ s men sailed from France aboard the transport " Corrèze " and reached Hanoi on 24 February . The instructions that accompanied the reinforcements specified that they were not to be used to extend the French occupation of Tonkin . On 8 March , Rivière learned that the Annamese government was planning to lease the coal mines at Hon Gai , a coastal town near Haiphong , to a Chinese consortium which was really a front for a British company . If the British were allowed to install themselves at Hon Gai , France could bid farewell to its dreams of colonial expansion in Tonkin . In defiance of both the letter and the spirit of his instructions , Rivière immediately decided to take the initiative . On his orders , Commandant Berthe de Villers left the following day aboard " Parseval " , raised the French tricolour in Hon Gai and established a post of 50 men there . The French met no resistance . In his report on this action to Charles Thomson , the governor of Cochinchina , Rivière explained that he had occupied Hon Gai primarily to secure his line of communications with Haiphong . But he did not hide the fact that he was also attempting to extend French control of Tonkin . With his friends , he was even franker . ' I have taken possession of the entire mining district , ' he wrote . ' We have always coveted it , but have always hesitated to act . This will force them to take forward their Tonkin Question ! ' The decision to attack Nam Dinh . Rivière also believed that , in his present situation , doing nothing was more dangerous than taking the initiative . Alarming news was coming in from both the north and the south . At Son Tay , Liu Yongfu was preparing to attack the French in Hanoi with 5 , 000 men of the Black Flag Army . In the Delta , the governor of Nam Dinh had armed the citadel , and the French gunboats were having great difficulty in preventing him from blocking the canals . Rivière was convinced that France should strike first . Now , at last , he had the means to act . ' As this indecisive government has been imprudent enough to send me 500 men , ' he wrote to a friend , ' I have decided to use them to do what it did not decide I should do . ' Rivière decided to strike at Nam Dinh , again in order to secure his communications with the coast . It was the strategy that Francis Garnier had adopted in 1873 , and it was probably the right one . But the decision aroused considerable opposition among his officers . They argued that it would result in a most undesirable division of the small French force at Hanoi . Nam Dinh would have to be garrisonned if it fell , and the French would then be too stretched to carry out further military operations . They recommended that the French should instead attack Liu Yongfu in Son Tay with all their available forces . Rivière was not convinced . He believed , probably rightly , that the French were not strong enough to take on Liu Yongfu . He overruled his officers and ordered plans to be prepared for an expedition against Nam Dinh . Eleven months after French troops had gone into action at Hanoi , Rivière once again threw down the gauntlet to the Vietnamese and Chinese courts . Nam Dinh was defended by 6 , 200 Vietnamese soldiers under the command of the " tong doc " ( governor ) Vu Truong Binh , assisted by the " de doc " Le Van Diem and the " quan an " Ho Ba On . A contingent of 600 Chinese soldiers from the Chinese garrison of Bac Ninh also fought covertly on the Vietnamese side , led by the Black Flag officer Vinh Thong Chat . As France and China were not at war , the Chinese troops wore Black Flag uniforms to disguise their participation in the battle . The Nam Dinh campaign . " Chef de bataillon " Pierre de Badens ( 1847 – 97 ) made a reconnaissance of Nam Dinh on 11 March by boat , and reported that it had been put into a good state of defence and was garrisoned by an army of 8 , 000 to 10 , 000 men . Rivière nevertheless decided to attack the city , and assembled a flotilla of junks and steam - launches to transport four and a half marine infantry companies under Colonel Carreau ’ s command and a detachment of Cochinchinese riflemen ( " tirailleurs annamites " ) — 520 men in all — down the Red River to Nam Dinh . This was a breathtakingly small attacking force , but it would be supported by several gunboats , whose firepower would enormously increase the chances of success . Rivière took personal command of the expedition , and his flotilla left Hanoi on 23 March , accompanied by the gunboats " Hache " and " Yatagan " . Berthe de Villers was left to defend Hanoi with three and a half companies of infantry and the gunboat " Léopard " . The expedition had first to run the gauntlet of the defences of Ninh Binh , whose citadel was built on a massive crag overlooking the Red River and was defended by a number of cannon which completely commanded the passage . The flotilla reached Ninh Binh on the afternoon of 24 March , to find the gunboat " Carabine " waiting . This was a critical moment . The garrison of the citadel stood to arms at the French approach , and according to Rivière ' their guns , if well handled , could have annihilated us ' . However , the governor of Ninh Binh declined to open fire , being ' one of those Asiatics who do not normally concern themselves with the misfortunes of their colleagues unless they affect them personally ' . The expedition passed Ninh Binh unharmed , and anchored that evening at the entrance to the Nam Dinh canal , where it was joined by the gunboats " Pluvier " and " Surprise " . On the morning of 25 March , the flotilla anchored off the southern wall of the citadel of Nam Dinh , where the gunboat " Fanfare " was already in position . Rivière now had five gunboats at his disposal . In the early afternoon French marine infantry went ashore and occupied the Nam Dinh naval barracks , evacuated by the city ' s defenders , without resistance . Later in the afternoon sailors from " Fanfare " went ashore and burned a number of wooden huts to obtain a clear field of fire for the gunboat ' s artillery . Several Vietnamese cannon responded to this provocation by opening fire , with little effect , on the French gunboat . " Fanfare " replied , and dismounted four artillery pieces on the city ' s ramparts . The action died down by nightfall , and did not become general . While this exchange of fire was in progress Rivière summoned the city ’ s governor Vu Truong Binh to present himself in person aboard " Pluvier " and to hand over the citadel before 8 a . m . on the following day . The governor ’ s refusal arrived in the evening . The bombardment of Nam Dinh . The walls of Nam Dinh were fifteen feet thick and solidly reveted . They could not be scaled by the attackers , as they were protected by deep ditches filled with water . Knowing that it would be impossible to breach the walls with the small - calibre cannon of the French gunboats , Rivière decided to force an entrance into Nam Dinh by destroying one of the main gates with explosives . He nevertheless ordered a preliminary bombardment of the city ' s ramparts by the gunboats , hoping to dismount as many Vietnamese artillery pieces as possible before his infantry and engineers made their assault . On the evening of 25 March the gunboats deployed along the Nam Dinh canal into a long line opposite the southeast wall of the citadel , enabling them to bring the defenders under a punishing crossfire . Rivière wanted to open fire as soon as the ultimatum expired , but it was so foggy on the morning of 26 March that action was impossible . However , the fog cleared in the early afternoon , and " Fanfare " moved up close to the southeast wall and began to bombard Nam Dinh ' s outer defences at 2 p . m . , firing slowly and accurately to dismount the guns facing the canal . To keep the defenders under cover , both " Fanfare " and " Pluvier " engaged them with their Hotchkiss " canons - revolvers " . After two hours , the fire from the southern defences slackened and " Fanfare " withdrew , having suffered only minor damage from two hits by enemy cannonballs . Many of the guns in the citadel had ignored the French gunboats , and fired instead on a nearby Roman Catholic mission . The capture of Nam Dinh . Rivière assaulted Nam Dinh the following day . He disembarked his force at 11 a . m . , after a devastating five - hour bombardment of the citadel by the gunboats . The attack force numbered just under 600 men , as Rivière supported the marine infantry and Cochinchinese riflemen with the landing companies of the gunboats " Pluvier " and " Fanfare " . The troops went ashore in a suburb beyond the city ’ s outer walls and were able to advance under cover of the buildings until they reached the main defences . In accordance with Rivière ' s plan , " capitaine du génie " Dupommier used dynamite charges to blow in the gate of the eastern demilune , then the eastern gate of the citadel . Dupommier and his party of engineers came under heavy fire from the Vietnamese defenders as they advanced to lay their charges , and had to fall back and wait for covering fire before making a second attempt . Once both gates had been blown in , the French charged into the citadel . Rivière led from the front , urging on his troops as they fought their way into the city and setting an example of personal courage . The Vietnamese resisted fiercely , but were overwhelmed by the superior firepower and morale of the French . By late afternoon the city was in French hands and its governor in flight . Sailors from " Fanfare " and " Pluvier " reached the summit of the citadel together . Unable to agree on who was first to the top , they hauled down the Annamese flag and hoisted two French flags in its place . A large Vietnamese force outside the city attempted to attack the French gunboats in the early evening , but was shelled in the open and quickly dispersed . French casualties in this operation were remarkably light : only four men wounded . However , one of the casualties was Lieutenant - Colonel Carreau , the commander of the expeditionary battalion , whose foot was smashed by a cannonball . His leg was later amputated , but his condition worsened and he died on 13 May . Vietnamese casualties are not known , but according to Rivière the defenders fought with unusual stubbornness , and when the French entered the city they found its walls piled with corpses . Aftermath . The French found 98 cannon in the citadel of Nam Dinh , including five 30 - millimetre rifled French guns ceded under the 1874 treaty . As the citadel was smaller than Hanoi ’ s and remained defensible despite the bombardment it had just suffered , Rivière decided to occupy it . He appointed " chef de bataillon " Badens " commandant supérieur " of Nam Dinh , giving him a garrison of 440 men and two gunboats . Badens quickly restored order in the town and reconstituted its municipal government , appointing new magistrates on the advice of the head of the local Catholic mission . By 31 March , when Rivière returned to Hanoi , the shops had reopened and many of the inhabitants had returned . Rivière praised the conduct of the marine infantry who had made the assault , some of whom had also taken part in the capture of Hanoi citadel on 25 April 1882 , in the following order of the day : Vous venez de montrer , à la prise de la citadelle de Nam - Dinh , le même entrain , la même valeur , le même dévouement qu ’ à la prise de la citadelle d ’ Hanoï . Je vous confonds les uns et les autres , les anciens comme les nouveaux , dans cet éloge , que notre brave colonel blessé à votre tête vous décerne comme moi . La Patrie , qui vous suit de cœur dans les pays lointains où nous sommes , tressaillera bientôt d ’ émotion et d ’ orgueil en apprenant ce que vous avez fait . Vive la France ! ( You have just shown , at the capture of the citadel of Nam Dinh , the same enthusiasm , the same valour and the same devotion as at the capture of the citadel of Hanoi . I congratulate you all , making no distinction between those there then and those here now , between old hands and newcomers ; and our brave colonel who was wounded at your head sees you as I do . Our country , whose heart has followed you into these far - off regions , will soon thrill with emotion and pride when it learns what you have done . Long live France ! )