A joint Franco-Spanish expedition under the command of Admiral Charles Rigault de Genouilly captured Tourane (modern Da Nang) in September 1858, but was then besieged in the city by the Vietnamese and forced eventually to evacuate it in March 1860.

France and Britain had just dispatched a joint military expedition to the Qing Empire as part of the Second Opium War, and the French had troops to hand with which to intervene in Vietnam.

In November 1857, the French emperor Napoleon III authorized Admiral Charles Rigault de Genouilly to launch a punitive expedition to teach the Vietnamese a long overdue lesson.

In the following September, a joint French and Spanish expedition landed at Tourane, whose fine, sheltered harbor would make it a good base of operations for a campaign against Annam.

He was accompanied by the screw-powered 12-gun corvettes Primauguet and Phlégéton, the steam-gunboats Alarme, Avalanche, Dragonne, Fusée and Mitraille, and the steam transports Durance, Saône, Gironde, Dordogne and Meurthe.

[Note 1] The transports carried a landing force of two overstrength battalions of French marine infantry (1,000 men), a marine artillery battery and 1,000 troops drawn from the Spanish garrison of the Philippines (550 Spanish troops and 450 Filipino light infantry, mostly Tagalogs and Visayans, known to the French as chasseurs Tagals).

The Vietnamese had built five major forts along the sheltered western side of the peninsula, covering the approaches to the town (see map).

The cannons, of large and medium caliber, were mounted upon modern gun-carriages, the powder came from Britain, and the infantry was armed with good rifles, made in Belgium or France.

Their arms, in the hands of trained soldiers, would be capable of sinking the entire naval division, and we were expecting the defenders at the very least to put up a serious resistance to it.

[12] Most of the Vietnamese made their escape from the Tiên Sa Peninsula, but the defenders of Observatory Fort were unable to evacuate their positions in time.

[14] Admiral Rigault de Genouilly left Da Nang with the bulk of his forces on 2 February 1859, to launch an attack on Saigon.

The French left only a small garrison of soldiers and sailors at Tourane, under the command of capitaine de vaisseau Thoyon, and two gunboats.

The Vietnamese adopted a scorched earth policy, laying waste the countryside around Tourane in the hope of starving the French and Spanish out.

[15] In April 1859, in the wake of his Siege of Saigon on 17 February, Rigault de Genouilly returned to Tourane with the bulk of his forces to reinforce Thoyon's hard-pressed garrison.

Ditches filled with water had been dug in front of the trenches, and the defenses were crowned with bamboo stakes filed to sharp points.

[19] In the autumn of 1859, Rigault de Genouilly, whose conduct of the war had come under criticism, was repatriated to France and replaced in command of the allied expedition by Rear Admiral François Page.

Page disembarked in Tourane on 19 October, and immediately after his arrival offered peace terms to the Vietnamese: an end to the persecution of Christians, the installation of French consuls in Vietnam and certain commercial privileges.

On 18 November 1859, Némésis and Phlégéton (towed respectively by Prégent and Norzagaray, a dispatch vessel recently bought at Manila), the gunboats Avalanche and Alarme, the transport Marne and the Spanish dispatch vessel Jorgo Juan (which had replaced El Caño) anchored off the Kien Chan forts and opened a devastating bombardment.