In 1884, the French transformed the region into a protectorate called Annam Empire. The most important city was Huế, as well as Đà Nẵng and Vinh. The Empire had a dual system of French and Vietnamese administration. The Nguyen Dynasty still ruled Annam nominally. A doll emperor lived in Huế.

In 1882 there were armed conflicts between China and France around the Annam region. With the Peace of Tientsin in 1885, the Chinese finally left Annam to the French as a protectorate.

During the Second World War until August 1945 Vietnam was administered by Japan. However, this happened until the spring of 1945 in collaboration with the French colonial administration. As a result, the discontent of the Vietnamese increased. Because an increasing demand of the occupiers for more and more food led to a catastrophic famine in 1945, which killed an estimated two million people. After the end of World War II Annam or rather Vietnam was briefly achieved political independence. But it was not until the decisions of the Indochina Conference in 1954 that the French withdrew from Annam and from all over Vietnam.

After that happends came the partition of Vietnam, after the fight of Viet Minh against the French occupation forces. While China supported the insurgents with weapons after 1949, the US intervened on the French side. Nevertheless, the French troops were subject to the Viet Minh in March 1954 at the Battle of Dien Bien Phu. At the subsequent Geneva Indo-China conference, the country was divided at the 17th degree of latitude into communist North Vietnam and western-oriented South Vietnam.