Cochinchina Campaign - Background

Background

The French had few pretexts to justify their imperial ambitions in Indochina. In the early years of the 19th century some Frenchmen believed that the Vietnamese emperor Gia Long owed the French a favour for the help French troops had given him in 1802 against his Tây Sơn enemies, but it soon became clear that the Gia Long felt no more bound to France than he did to China, which had also provided help. Gia Long felt that as the French government did not honour their agreement to assist him in the civil war—the Frenchmen who helped him were volunteers and adventurers not government units—he was not obliged to give them favours. Certainly, he and his successor Minh Mạng flirted with the French. Although the Vietnamese soon learned to reproduce the elaborate Vaubanesque fortresses that had been built at the end of the 18th century by French engineers, and no longer needed French technical assistance in the art of fortification, they were still interested in buying French cannon and rifles. But this limited contact with the French counted for little. Neither Gia Long nor Minh Mạng had any intention of coming under French influence.

But the French were not prepared to be brushed off quite so easily. As so often during the era of European colonial expansion, religion offered an excuse for intervention. French missionaries had been active in Vietnam since the 17th century, and by the middle of the 19th century there were perhaps 300,000 Roman Catholic converts in Annam and Tonkin. Most of their bishops and priests were either French or Spanish. Most Vietnamese disliked and suspected this sizeable Christian community and its foreign leaders. The French, conversely, began to feel responsible for their safety. Harassment of the Christians eventually provided France with a respectable pretext for attacking Vietnam. The tension built up gradually. During the 1840s, persecution or harassment of Catholic missionaries in Vietnam by the Vietnamese emperors Minh Mạng and Thieu Tri evoked only sporadic and unofficial French reprisals. The decisive step towards the establishment of a French colonial empire in Indochina was not taken until 1858.

In 1857, the Vietnamese emperor Tu Duc (r. 1848–83) executed two Spanish Catholic missionaries. This was neither the first nor the last such incident, and on previous occasions the French government had overlooked such provocations. But this time, Tu Duc's timing was inopportune, as it coincided with the Second Opium War. France and Britain had just despatched a joint military expedition to the Far East to chastise China, with the result that the French had troops on hand with which to intervene in Annam. In November 1857, Napoleon III of France authorised Admiral Charles Rigault de Genouilly to send a punitive expedition to Vietnam. In September 1858, a joint French and Spanish expedition landed at Tourane (Da Nang) and captured the town.