Construction of Hue’s imperial capital began under Emperor Gia Long in 1803 and continued under Emperor Minh Mang, with the main Imperial City completed in 1832. Its layout reflects traditional Vietnamese court planning and East Asian cosmological principles, combined with elements of European military fortification. Surrounded by defensive walls and a moat, the wider citadel contains successive enclosures that separated administrative functions, royal ceremonies and the private life of the imperial family.

The Imperial City, known in Vietnamese as Hoang Thanh, served as the centre of royal government and ceremonial life. Its principal entrance, Ngo Mon Gate, leads towards Thai Hoa Palace, where emperors held important court ceremonies. Within the surrounding courtyards are temples dedicated to the Nguyen emperors and their ancestors, royal residences, landscaped gardens and other structures that reflect the dynasty’s political authority, spiritual traditions and artistic achievements.

At the heart of the complex lies the Forbidden Purple City, or Tu Cam Thanh, once reserved for the emperor and members of the royal household. It originally contained residential quarters, private palaces and supporting facilities, many of which were severely damaged during 20th-century conflicts. Surviving structures, archaeological remains and ongoing restoration work reveal both the scale of the former royal residence and the challenges of preserving this historic heritage. Together, the Imperial City and Forbidden Purple City offer an important insight into the court culture, architecture and history of Vietnam’s last royal dynasty.