Duy Tân (at the time, known by his birth name, Prince Nguyễn Phúc Vĩnh San) was son of the Thành Thái emperor.

As he became a teenager, Emperor Duy Tân came under the influence of the mandarin Trần Cao Vân, who was very much opposed to the colonial administration.

Emperor Duy Tân began to plan a secret rebellion with Trần Cao Vân and others to overthrow the French.

In 1916, while France was preoccupied with fighting World War I, Emperor Duy Tân was smuggled out of the Forbidden City with Trần Cao Vân to call upon the people to rise up against the French.

[citation needed] When France was facing defeat by the Viet Minh, and the regime of Emperor Bảo Đại proved incapable of gaining any public support, French leader Charles de Gaulle talked to Prince Vĩnh San, who was still very popular in the Vietnamese public memory for his patriotism, about returning to Vietnam as emperor.