The history of Duc Duc's mausoleum is also complicated by internal fluctuations in the court and royal families of the Nguyen Dynasty, since Emperor Tu Duc ascended to the throne on July 19, 1883. Because Tu Duc Emperor had no children to succeed to the throne, the throne of the Nguyen court became bloody due to the manipulation to hold power between on the one hand the Grand Councilors of Ton That Thuyet, Nguyen Van Tuong, and the French Nunciature the other. That throne has been inherited by three kings, Duc Duc, Hiep Hoa and Kien Phuc, continuously for only 4 months, used to be called the "Tu Nguyet Tam Vuong", then continued to be transferred to 4 more kings within a short time: Ham Nghi, Dong Khanh, Thanh Thai and Duy Tan.
Duc Duc emperor's real name is Nguyen Phuc Ung Chan, born in 1852, when he was 2 years old, was chosen by Tu Duc emperor to be adopted and stayed in Duc Duc Duong in the Citadel. This eldest prince married the daughter of the great minister Phan Dinh Binh; in 1879, he gave birth to Buu Lan, the future King Thanh Thai. When King Tu Duc died, the 32-year-old prince ascended the throne, but after only three days was dethroned (July 23, 1883) and under supervision at the Thai Y Vien, eventually starving to death in Thua Thien prison after 7 days of no food and drink (October 6, 1883); leaving 8 wives, 11 sons and 8 daughters. The tomb is temporarily buried in Phuoc Qua, near Tuong Quang Pagoda. A few days later, the court gave the main wife, Mrs. Tu Minh, permission to visit the tomb and perform a funeral ceremony at Tuong Quang Pagoda.
After many unpredictable events, in the specific conditions of the historical context, Duc Duc's son Nguyen Phuc Buu Lan was crowned king in 1889, with the title Thanh Thai. After ascending the throne, Thanh Thai immediately built his father's tomb and named it An Mausoleum. The place of worship is Tuong Quang pagoda 200 meters away. In 1891, Thanh Thai emperor's court built a temple in Thuan Cat ward, near the right of the Imperial City to worship King Duc Duc, named Tan Mieu (In 1897, it was renamed Cung Ton Mieu). In 1892, Mrs. Tu Minh empress dowager queen - the mother of Thanh Thai Emperor gave money to mint Buddha statues and expand the monastic house of Tuong Quang Pagoda, the following year the Thanh Thai Emperor changed the name to Kim Quang Pagoda and gave the pagoda a 5-word titled "Sac Tu Kim Quang Tu".
On July, the 11th Thanh Thai (8-1899), the king built Long An palace near the tomb of Duc Duc emperor to worship his father. In this campus, there are some additional buildings such as Ta Huu Phoi Duong, Ta Huu Tong Vien for 7 wives of King Duc Duc to live and to take care of worship. In 1906, Mrs. Tu Minh died, the court re-planned the tomb area of Duc Duc emperor, made a double mausoleum, and built her tomb near his tomb in the style of "double burial", "wisdom and virtue" as in the tomb of the The To Cao Emperor and Thua Thien Cao Empress (Gia Long mausoleum). In late 1945, shortly after King Duy Tan died in a plane crash in Africa, a memorial ceremony was held at Long An Palace and also worshiped here. In 1954, when King Thanh Thai died, his body was buried at the current site in the An Lang area and worshiped at Long An Palace. In 1987, Duy Tan Emperor's remains were buried next to Thanh Thai mausoleum. Nearby the tombs of Thanh Thai and Duy Tan emperors, there are also the tombs of three wives of Thanh Thai emperor. And in 1994, the remains of Mai Thi Vang (who died in 1980), the wife of Duy Tan emperor, were buried near the tomb of the patriotic king - Duy Tan.
In addition, in the area of Duc Duc mausoleum, there are 39 tombs of princes and princesses and 121 tombs belonging to the Fourth Generation of Nguyen Lords.
Duc Duc Mausoleum before restored