Battle of Thuận An The Battle of Thuan An ( 20 August 1883 ) was a clash between the French and the Vietnamese during the period of early hostilities of the Tonkin Campaign ( 1883 to 1886 ) . During the battle a French landing force under the command of Admiral Amédée Courbet stormed the coastal forts that guarded the river approaches to the Vietnamese capital Huế , enabling the French to dictate a treaty to the Vietnamese that recognised a French protectorate over Tonkin . The French strike against the Vietnamese in August 1883 , sanctioned by Jules Ferry ' s administration in Paris , did more than anything else to make a war between France and China inevitable , and sowed the seeds of the Vietnamese Can Vuong national uprising in July 1885 . Background . On 30 July 1883 , Admiral Courbet , General Bouët and Jules Harmand , the French civil commissioner - general for Tonkin , held a council of war at Haiphong . The meeting noted that the Court of Huế was covertly aiding and abetting Liu Yongfu ' s Black Flag Army , and that the Vietnamese commander - in - chief Prince Hoang Ke Viem was openly in arms against the French at Nam Định . The three men agreed that Bouët should launch an offensive against the Black Flag Army in its positions around Phu Hoai on the Day River as soon as possible . They also decided , largely on Harmand ' s urging , to recommend to the French government a strike against the Vietnamese defences of Huế , followed by an ultimatum requiring the Vietnamese to accept a French protectorate over Tonkin or face immediate attack . Jules Ferry ' s government was initially reluctant to sanction an attack on Huế , fearing that it might provoke a response from China , but the French minister to China , Arthur Tricou , convinced the French government that China would acquiesce in a French ' act of virility ' . On 11 August the navy minister Charles Brun approved Harmand and Courbet ' s proposal for a naval descent on Huế to coerce the Vietnamese court . The aim of the expedition was to put a landing force ashore to capture the Thuan An forts , which guarded the entrance to the River of Perfumes , after a preliminary bombardment by the warships of Courbet ' s Tonkin Coasts naval division . As the Tonkin Expeditionary Corps would be fully committed to Bouët ' s projected attack on the Black Flag Army , it was agreed that the landing near Huế would be made by troops from the French garrisons in Cochinchina . On 16 August Courbet left Along Bay aboard his flagship " Bayard " , and on 16 August anchored at the entrance to the Perfume River and scouted the Thuan An fortifications . Meanwhile a strong flotilla of the Tonkin Coasts naval division had concentrated in Tourane Bay . Courbet ' s naval force for the descent on Huế consisted of the ironclads " Bayard " and " Atalante " , the cruiser " Châteaurenault " , the gunboats " Lynx " and " Vipère " and the transport " Drac " . This force was joined by the troopship " Annamite " , which sailed up from Saigon with a landing force of 600 marine infantry and 100 Cochinchinese riflemen and a marine artillery battery . The naval bombardment . Courbet returned to Tourane Bay with " Bayard " on the evening of 16 August and issued his orders for an attack on the Thuan An forts on 18 August . On 17 August the French rehearsed their plans for the attack . The French naval division left Tourane at 8 a . m . on 18 August , in order of battle with " Bayard " at its head , and anchored off the entrance to the Huế River around 2 p . m . The ships took up positions for the impending attack . " Bayard " took station at the entrance to the river , to be able to fire both upon the southern forts and on the large northern fort , 2 , 000 metres away . " Châteaurenault " was a little to the east , and was charged with attacking the southern forts only . " Atalante " , to the west of " Bayard " , was tasked with attacking the large northern fort , and " Drac " , anchored on the western flank of the French line , was to take on the small forts at the end of the enemy positions . The gunboats " Lynx " and " Vipère " , placed between " Atalante " and " Drac " , were to move in close and protect the landing . " Annamite " remained in the rear . An attempt to negotiate was made by the Vietnamese , and discussions took up much of the afternoon . Courbet finally demanded that the Thuan An forts should be handed over to the French within two hours . This ultimatum was delivered by the Vietnamese envoys to the fort commanders , who declined to reply . At 5 . 40 p . m . on 18 August the ships of the naval division hoisted a French flag at each masthead , " Bayard " opened fire , and the entire division immediately followed suit . The light frigate " Alouette " from Cochinchina joined the division shortly before hostilities commenced , and Courbet ascertained that she had no new orders for him before opening fire . The Vietnamese defenders replied , although outgunned , but the French ships were out of range of their antiquated cannon . The bombardment lasted for just over an hour , until it became too dark to fire effectively . The guns stopped firing at 7 p . m . , and the French ships turned on their powerful electric searchlights to illuminate the forts , the Thuan An pass and the sea around their anchorage , in case of an enemy night attack . Orders were given for a landing at dawn on 19 August . The men turned in early , and when the drums beat to quarters at 4 a . m . the officers and sailors of the landing companies prepared to man the boats . But shortly before dawn Courbet changed his mind and cancelled the landing . The sea was very rough , and he may also have considered that the previous day ' s bombardment had not done enough damage . At dawn the French resumed their bombardment . To their surprise the Vietnamese replied with a well - aimed salvo of shells which whistled overhead and fell in the sea close around the French ships . They had taken advantage of the darkness to bring up rifled guns with a longer range . Although the French naval division was soon able to silence these guns , they scored a number of minor hits . " Vipère " and the ironclad " Bayard " were struck several times during these exchanges of fire , but were not seriously damaged . The attack on the Thuan An forts . The sun rose on 20 August on a completely calm sea . At 5 . 30 a . m . Courbet decided to proceed immediately with the landing . Just over a thousand men ( the two marine infantry companies , the Cochinchinese riflemen and the landing companies of " Bayard " , " Atalante " and " Châteaurenault " ) would go ashore under the command of Captain Parrayon of " Bayard " and seize the Northern Fort . The landing was made in two stages . At 5 . 45 a . m . an advance guard under Parrayon ' s personal command , consisting of the three ships ’ landing companies and two sections of marine infantry , climbed into the launches and made slowly for the shore . Half an hour later this detachment struggled ashore in the sand dunes in front of the Vietnamese defences . The Vietnamese , snug in their trenches overlooking the beach , began to hurl firecrackers at the attackers . " Lynx " and " Vipère " , anchored just offshore , responded with cannon and rifle fire , while the crews of the French launches fired their Hotchkiss " canons - revolvers " . Under this covering fire , the landing companies were able to move slowly forward from the beach . A spearhead led by " enseigne de vaisseau " Olivieri crossed the beach defences and fought a brief action with a party of Vietnamese who left their entrenchments to confront the invaders . The Vietnamese were quickly routed . At the same time the landing company of " Atalante " came up in support , under the command of " lieutenant de vaisseau " Poidloue , and captured a battery of cannon commanding a stretch of the river . This feat enabled Parrayon to attack the village and the Northern Fort , which he carried without firing a shot . Meanwhile the French had , with some difficulty , landed the 65 - millimetre guns of Luce ' s battery on the dunes , and these also supported the French attack . The Vietnamese gradually gave way and eventually retreated , burning the village as they went . The ships of the naval division continued to fire throughout the action , laying down a barrage ahead of the landing force that paved the way for its advance . At 8 a . m . Captain Sorin landed with the bulk of the marine infantry and linked up with the first detachment in front of the principal fort . After about an hour ' s fighting Captain Parrayon , Ensign Olivieri and " lieutenant de vaisseau " Palma Gourdon ( who would later win fame in the Battle of Shipu ) were among the first French soldiers to enter the fort . Shortly after 9 a . m . the French flag was hoisted on the citadel ' s flagpole , to the cheers of all the men of the naval division . During the morning battle the French had captured the Northern Fort . But the Southern Fort still remained in Vietnamese hands . In the afternoon , in order to prepare the way for an attack on the Southern Fort , the gunboats " Lynx " and " Vipère " boldly crossed the river barrage . The fort ' s guns engaged them gamely , and the two gunboats fired back . Out at sea , " Bayard " and " Châteaurenault " added the weight of their own fire to the contest . The French had the better of this artillery duel . The fire from the fort slackened . On the morning of 21 August the division ' s launches landed a strong French column on the beach opposite the Southern Fort , ready to attack it if necessary . But there was no need . The fort and the neighbouring villages were completely empty . The Annamese had evacuated their last defences , and there was now nothing to stop the French from sailing up the River of Perfumes to Huế . Vietnamese losses during the bombardment and subsequent landing had been heavy , perhaps 2 , 500 men killed or wounded . French casualties , by contrast had been derisory , only a dozen men wounded . On the following day Courbet congratulated his troops on their success , singling out the officers and crew of " Lynx " and " Vipère " for special commendation . The Treaty of Huế . The French capture of the Thuan An forts , which exposed Huế to immediate attack , overawed the Vietnamese court . An armistice was quickly agreed with the French . Harmand threatened the Vietnamese with annihilation unless they immediately accepted a French protectorate over both Annam and Tonkin . On 25 August 1883 , cowed by the French appeal to force , the Vietnamese signed the Treaty of Huế . The Treaty of Huế ( 1883 ) gave France everything it wanted from Vietnam . The Vietnamese recognised the legitimacy of the French occupation of Cochinchina , accepted a French protectorate both for Annam and Tonkin and promised to withdraw their troops from Tonkin . Vietnam , its royal house and its court survived , but under French direction . France was granted the privilege of stationing a resident - general at Huế , who would work to the civil commissioner - general in Tonkin and could require a personal audience with the Vietnamese king ( a concession that the Vietnamese had never before been prepared to make ) . To ensure there were no second thoughts , a permanent French garrison would occupy the Thuan An forts . Large swathes of territory were also transferred from Annam to Cochinchina and Tonkin . The French cancelled the country ' s debts , but required in return the cession of the southern province of Bình Thuận , which was annexed to the French colony of Cochinchina . At the same time the northern provinces of Nghệ An , Thanh Hóa and Hà Tĩnh were transferred to Tonkin , where they would come under direct French oversight . In return the French undertook to drive out the Black Flags from Tonkin and to guarantee freedom of commerce on the Red River . These were hardly concessions , since they were planning to do both anyway . Order of the day . Courbet issued the following order of the day to his sailors and soldiers to commemorate the victory at Thuan An : Vous avez vaillamment combattu . Vous avez montré une fois de plus ce que la France peut attendre de votre patriotisme . Le roi d ' Annam a demandé une suspension d ' armes , le commissaire général civil est a Hué pour traiter . En quelques jours , vous avez donné un nouveau prestige au nom français dans l ' Extrême - Orient . Voilà les premiers résultats de vos succès . La France entière y applaudira ! ( You have fought valiantly . You have shown once again what France can expect from your patriotism . The king of Annam has asked for an armistice , and the civil commissioner - general has gone to Huế to negotiate . In a few days you have given a new prestige to the name of France in the Far East . Here are the first fruits of your victories . All France will applaud them ! ) Pierre Loti and the battle of Thuan An . " Enseigne de vaisseau " Louis - Marie - Julien Viaud ( 1850 – 1923 ) , who served in Courbet ' s Tonkin Coasts naval division aboard the ironclad " Atalante " , described his campaigning experiences in a number of popular articles published under the pen name Pierre Loti . He wrote a detailed account of the battle of Thuan An entitled " Trois journées de guerre en Annam " , which was published in three parts in Le Figaro on 28 September and 13 and 17 October 1883 . Viaud ' s brutally realistic description of the fighting at Thuan An , his account of French atrocities ( the bayoneting of wounded Vietnamese soldiers by French marine infantrymen after the battle ) and the obvious pleasure he took in the slaughter of the outclassed Vietnamese , caused great offence in France , and he was recalled by the navy ministry and suspended from duty .