The French were Vietnam's colonial parent. French colonialism in Vietnam lasted more than six decades, and by the late 1880s France controlled Vietnam.
Whatever economic process Vietnam made under the French after 1900 benefited only the French and the small class of wealthy Vietnamese created by the colonial regime. The masses of the Vietnamese people were deprived of such benefits by the social policies.
The decision to invade Vietnam was made by Napoleon III in July of 1857. It was the result not only of missionary propaganda, but also, after 1850, of the upsurge of French Capitalism. This generated the need of overseas markets and the desire for a larger French share of the Asian territories conquered by the West.
The French colonized Vietnam in the mid 1800s. In 1885, France looked to take over Vietnam and in 1887 they did it. The French started to immigrate to more Western ideals, education, and religion including Christianity.