French and Spanish forces defeat the Vietnamese at Kỳ Hòa

Background. Following the capture of Saigon in February 1859, the Cochinchina campaign reached a strategic equilibrium. A small Franco-Spanish garrison faced a superior Vietnamese army besieging the city from March 1860. The French had failed to achieve decisive gains at Tourane or Saigon during 1859 and 1860, forcing them to hold only one position. The situation changed when reinforcements arrived from the China expedition, enabling a breakout from the siege.

Reinforcements. The end of the Second Opium War in 1860 allowed the French government to despatch significant reinforcements to Cochinchina. Admiral Léonard Charner arrived with 70 ships, and General Élie de Vassoigne brought 3,500 soldiers. These forces, previously diverted to support operations in China, returned to Saigon in early 1861. Their arrival overwhelmed the Vietnamese strongholds and provided the numerical superiority necessary to assault the siege lines.

Outcome. The assault on the Ky Hoa lines successfully defeated the Vietnamese defenders, breaking the siege of Saigon. This victory allowed the French to regain the initiative in the campaign. In April 1861, the city of Mỹ Tho fell to the French without a shot being fired. The military success paved the way for harsher peace terms offered to Emperor Tự Đức in March 1861, which were significantly more demanding than previous negotiations.