Thành Thái
Duy Tân (at the time, known by his birth name, Prince Nguyễn Phúc Vĩnh San) was son of the Thành Thái emperor. Because of his opposition to French rule and his erratic, depraved actions (which some speculate were feigned to shield his opposition from the French) Thành Thái was declared insane and exiled to Vũng Tàu in 1907. The French decided to pass the throne to his son Nguyễn Phúc Vĩnh San, despite the fact that he was only seven years old. The French hoped that someone so young would be easily influenced and controlled, and thus raised to be pro-French.