Capture of Mỹ Tho The Capture of My Tho ( ) on 12 April 1861 was an important allied victory in the Cochinchina campaign ( 1858 – 62 ) . This campaign , fought between the French and the Spanish on the one side and the Vietnamese on the other , began as a limited punitive expedition and ended as a French war of conquest . The war concluded with the establishment of the French colony of Cochinchina , a development that inaugurated nearly a century of French colonial dominance in Vietnam . Background . After early French and Spanish victories at Tourane ( Da Nang ) and Saigon , the Cochinchina campaign reached a point of equilibrium in 1860 . In March 1860 the allies were forced to evacuate Tourane . At the same time they were besieged in Saigon , which had been captured by a Franco - Spanish expedition under the command of Admiral Charles Rigault de Genouilly on 17 February 1859 . The arrival of massive reinforcements from the French expeditionary corps in China in 1860 allowed the French to regain the initiative . In early 1861 Admiral Léonard Charner broke the Siege of Saigon by defeating the Vietnamese besieging army at the Battle of Ky Hoa ( 25 February 1861 ) . This victory gave Charner the opportunity to take the offensive against the Vietnamese , and he decided to strike first at My Tho and next at Bien Hoa . The My Tho expedition . The expedition against My Tho was initially led by " capitaine de frégate " Bourdais , captain of the aviso " Monge " . Besides " Monge " , the other warships at his disposal were the first - class gunboats " Alarme " and " Mitraille " and the small gunboats Nos . 18 and 31 , commanded respectively by " lieutenants de vaisseau " Sauze , Duval , Peyron and de Mauduit . The flotilla carried a landing force of 200 French sailors , 30 Spanish soldiers and one mountain mortar . Bourdais was ordered to advance on My Tho from the north , along a creek known to the French as the Arroyo de la Poste . On 1 and 2 April he bombarded and captured two forts at the entrance to the creek , and went on to destroy a series of stockades erected by the Vietnamese to bar access . On 4 April the expedition received important reinforcements from Saigon : 200 chasseurs , 100 sailors , two companies of marine infantry , two 40 - millimetre mountain guns and two mortars . These reinforcements arrived aboard the aviso " Echo " . Command of the expedition was now given to Charner ' s aide de camp " capitaine de vaisseau " Le Couriault du Quilio , assisted by " capitaine de frégate " Allizé de Montignicourt as chief of staff . A further reinforcement of 100 sailors arrived on 6 April , under the command of " capitaine de frégate " Desvaux . Between 6 and 11 April Le Couriault du Quilio ' s expedition fought its way along the Arroyo de la Poste , against Vietnamese resistance of varying intensity . On 8 April the expedition was reinforced with three more gunboats ( Nos . 16 , 20 and 22 ) , commanded respectively by " lieutenants de vaisseau " Gougeard , Béhic and Salmon . On the evening of 9 April the Vietnamese launched two fireships against the French gunboats . " Enseignes de vaisseau " Joucla and Besnard took both vessels under tow and ran them aground in a tributary creek , where they burned themselves out . On 10 April a French scouting party led by Captain du Chaffault advanced up to the walls of My Tho and exchanged shots with the defenders before returning to make its report . Le Couriault du Quilio pressed forward with his gunboats , which were towing several sloops carrying 300 soldiers and sailors . " Capitaine de frégate " Bourdais , the original expedition commander , led an attack on Fort No . 5 with Gunboat No . 18 ( see map ) , but was killed by a cannonball in the first exchange of fire . The French gunboats soon beat down the fire of the fort , and its defenders abandoned it before it was assaulted . The capture of this fort , renamed Fort Bourdais by the French , opened the route to My Tho . On 11 April the expedition closed up on My Tho , and prepared to assault the town on the following day . In the event , the assault was not necessary . A flotilla of warships under the command of Admiral François Page , who had been sent by Charner to sail up the Mekong river to attack My Tho by sea , presented itself before the town on 12 April . My Tho was occupied by the French on the same day without a shot being fired .