An Annamite ambassador

The state of Annam lay in what is now Central Vietnam, and had its capital at Hue. In 1858 France initiated a programme of military expansion in the area.

The First Treaty of Saigon, signed on 5 June 1862 between the French and the last pre-colonial emperor of Annam, Tu Duc, ceded Saigon, the island of Poulo Condor and three southern provinces of what was to become known as Cochinchina - Bien Hoa, Gia Dinh, and Dinh Tuong - to the French. The treaty was confirmed by the treaty of Hue signed on 14 April 1863. Furthermore, the treaty stipulated the opening of three Vietnamese ports to trade (Tourane, Balat and Quang Yên), freedom for missionary activity and French authority over Vietnam's foreign affairs. Also by this agreement, Saigon was declared the capital of French Indochine.