The party met with King Louis XVI on May 5 or 6, 1787. The Treaty of Versailles (1787) was signed on 28 November 1787. Prince Canh created a sensation at the court of Louis XVI, leading the famous hairdresser Léonard to create a hairstyle in his honour "au prince de Cochinchine". His portrait was made in France by Maupérin, and is now on display at the Séminaire des Missions Étrangères in Paris. Prince Canh dazzled the Court and even played with the son of Louis XVI, Louis-Joseph, Dauphin of France.
Prince Canh became highly favourable to Christianity. He strongly desired to be baptized, but Pigneau de Behaine refrained doing so in order to avoid a negative reaction at the Vietnamese court.
In 1793 Nguyen Phuc Canh became "Crown Prince of the Eastern Palace". From 1794 he participated to all the military expeditions, and his father Nguyen Anh insisted that he be accompanied everytime by Father Pigneau de Behaine. He was besieged by the Tay Son with Pigneau de Behaine in the citadel of Duyen Khanh in 1794.
After Pigneau de Behaine died at the Siege of Quy Nhon in 1799, Prince Canh made a funerary oration to his former master:
Prince Canh seems to have been baptized secretely towards the end of his life. According to Vietnamese annals:
He died in 1801 of smallpox. Missionaries claimed however that he was poisoned. As Nguyen Phuc Canh was the presumptive heir to Gia Long, Canh's eldest son Mỹ Đường was next in line for the succession.
Gia Long however changed the primogeniture rule of succession to include "testamental measures" (gia thien ha), and ultimately changed his successor to the fourth son of one of his concubines, who became emperor Minh Mang.
The 1833-1835 Le Van Khoi revolt attempted to reestablish Prince Canh's line to the throne. This choice was designed to obtain the support of Catholic missionaries and Vietnamese Catholic, who had been supporting with Le Van Duyet the line of Prince Canh.
My Duong's eldest son was Le Trung, who received the title of Marquis Ứng Hòa Hầu in 1826. Le Trung's eldest son was Anh Nhu (also known as Tang Nhu), who was considered as a candidate to the throne under French rule, following the establishment of the protectorate on Annam in 1884, and once again after the death of Dong Khanh in 1889.
Anh Nhu, grand-grandson of Prince Canh, was the father of Cường Để, the eldest son of three, who became a well-known independentist and collaborator with the Japanese during World War II. Cường Để, according to the old rule of primogeniture was the heir of the Nguyen dynasty.