Francis Garnier Marie Joseph François ( Francis ) Garnier ( ; 25 July 1839 - 21 December 1873 ) was a French officer and explorer known for his exploration of the Mekong River in Southeast Asia . Early career . He was born on July 25 , 1839 at Saint - Étienne , Loire , and entered the French Navy , and after voyaging in Brazilian waters and the Pacific , he obtained a post on the staff of Admiral Léonard Victor Charner , who from February 1860 to November 1861 was campaigning in Cochinchina . After some time spent in France , Garnier returned to the East , and in 1862 , he was appointed inspector of native affairs in Cochinchina , and entrusted with the administration of Cholon , a suburb of Saigon . Exploration of the Mekong and Yangtze rivers . It was at his suggestion that the marquis de Chasseloup - Laubat determined to send a mission to explore the valley of the Mekong River , but as Garnier was not considered old enough to be put in command , the chief authority was entrusted to Captain Ernest Doudard de Lagrée . In the course of the expedition - to quote the words of Sir Roderick Murchison addressed to the youthful traveller when , in 1870 , he was presented with the Victoria Medal of the Royal Geographical Society of London - " from Kratie in Cambodia to Shanghai 5392 miles were traversed , and of these , 3625 miles , chiefly of country unknown to European geography , were surveyed with care , and the positions fixed by astronomical observations , nearly the whole of the observations being taken by Garnier himself " . Volunteering to lead a detachment to Dali , the capital of Sultan Suleiman , the sovereign of the Muslim rebels in Yunnan , Garnier successfully carried out the more - than - adventurous enterprise . When shortly afterwards Lagrée died , Garnier naturally assumed the command of the expedition , and he conducted it in safety to the Yangtze River , and thus to the Chinese coast . On his return to France , he was received with enthusiasm . The preparation of his narrative was interrupted by the Franco - Prussian War , and during the siege of Paris , Garnier served as principal staff officer to the admiral in command of the eighth sector . His experiences during the siege were published anonymously in the " feuilleton " of " Le Temps " , and appeared separately as " Le Siège de Paris , journal d ' un officier de marine " ( 1871 ) . Returning to Cochinchina , he found the political circumstances of the country unfavourable to further exploration , so accordingly , he went to China , and in 1873 followed the upper course of the Yangtze River to the waterfall s . Intervention in Tonkin . Garnier met his death in controversial circumstances . In late 1873 he was sent by Admiral Dupré , the governor of Cochinchina , to Tonkin , to resolve a dispute between the Vietnamese authorities and the French entrepreneur Jean Dupuis . Persuaded that the time was ripe for a French conquest of Tonkin , Garnier captured Hanoi , the capital of Tonkin , 20 November 1873 . In the next few weeks a small French force under Garnier ' s command captured most of the citadels of the Red River Delta . The Vietnamese authorities , despairing of meeting the French with their own forces , appealed to the notorious Chinese soldier of fortune Liu Yongfu to come to their aid with his Black Flag Army . Defeat and death . On 21 December 1873 Liu Yongfu and around 600 Black Flags ( ) , marching beneath an enormous black banner , approached the west gate of Hanoi . A large Vietnamese army followed in their wake . Garnier began shelling the Black Flags with a field piece mounted above the gate , and when they began to fall back led a party of 18 French marine infantrymen out of the city to chase them away . The attack failed . Garnier , leading three men uphill in a bayonet attack on a party of Black Flags , was stabbed and hacked to death by several Black Flag soldiers after stumbling in a watercourse . The youthful " enseigne de vaisseau " Adrien - Paul Balny d ’ Avricourt led an equally small column out of the citadel to support Garnier , but was also killed at the head of his men . Three French soldiers were also killed in these sorties , and the others fled back to the citadel after their officers fell . Colonel Thomazi , the historian of French Indochina , gave the following detailed description of Garnier ' s last moments : At midday on 21 December he was in conference with the ambassadors when an interpreter ran up , announcing that bands of Black Flags were attacking the town by the western gate . He immediately hurried to the spot , but some of his men had got there before him , and their fire had sufficed to force the bandits to retreat behind the bamboo hedges . A 40 - millimetre gun arrived at this moment . Garnier rallied a dozen men , three of whom dragged this small cannon , and left the town at a run to pursue the enemy . As the gun could not move quickly enough across the fields , he left it behind with its gunners . He then divided the nine men who remained with him into three groups . The first two groups moved off to the left and the right , to rejoin one another further on , while he marched in the middle , followed only by two men . One and a half kilometres from the town he found himself in front of a dyke , and slipped and fell while trying to cross it . Some Black Flags hidden behind the dyke ran out , while others opened fire . At this moment the two men who were accompanying Garnier were 100 metres behind him . One of them was killed by a bullet and the other wounded . Garnier cried , ' To me , brave boys , and we ' ll give them a thrashing ! ' He then fired the six rounds from his revolver in an attempt to rescue himself , but the bandits surrounded him , pierced him with thrusts of sabres and lances , cut off his head , odiously mutilated his corpse , and ran away . The two other groups , rushing up to the sound of the shooting , were only able to recover his bloodied corpse and bring it back to Hanoi . Garnier ' s death effectively ended the first French adventure in Tonkin . The French government disavowed Garnier ' s adventure and hastened to conclude a peace settlement with the Vietnamese , abandoning most of its claims in Tonkin . Achievement . Garnier ' s chief fame rests on the fact that he originated the idea of exploring the Mekong , and carried out the larger portion of the work . During the French colonial period he was also honoured for his feats of arms in Tonkin , which paved the way for the eventual French conquest of Tonkin in the 1880s . Commemoration . In 1883 , nine years after Francis Garnier ' s death , the French naval officer Henri Rivière was also killed by the Black Flags in Tonkin , in remarkably similar circumstances . Garnier and Rivière were honoured during the French colonial period as the two pre - eminent French martyrs of the conquest of Tonkin . In 1884 , during the Sino - French War , two gunboats of the Tonkin Flotilla were named after the two men . During the siege of Tuyen Quang ( November 1884 – March 1885 ) , Liu Yung - fu ' s Black Flags , who formed part of the besieging Chinese army , taunted the men of the French garrison by chanting the names of their two most famous victims : ' Garnier ! Rivière ! Garnier ! Rivière ! ' In 1943 , French Indochina issued a postage stamp commemorating Garnier .