Gia Long
Nguyễn Phúc Ánh united Vietnam after a three-hundred-year division of the country. He celebrated his coronation at Huế on 1 June 1802 and proclaimed himself emperor (), with the era name Gia Long (嘉隆). Gia Long prioritized the nation's defense, and feared that it could again be divided by civil war. He replaced the feudal system with a reformist "Doctrine of the Mean", based on Confucianism. The Nguyen dynasty was founded as a tributary state of the Qing Empire, with Gia Long receiving an imperial pardon and recognition as the ruler of Vietnam from the Jiaqing Emperor for recognizing Chinese suzerainty.