In the 15th century, the Nguyen lords unified Vietnam for the first time since ancient history. Emperor Gia Long selected Hue as his capital because the pine hills on its three sides and the shallow Perfume River made the location easily defendable. The Nguyen Dynasty and Hue's golden age lasted for 13 kings, for over 150 years, until the Japanese invaded in WW II.

By the mid 1960's, Hue became a center of protest against the Thieu regime in Saigon (Ho Chi Minh City), and later a stronghold of the North Vietnamese Army. Throughout January and February 1968, during the Tet Offensive, American artillery and later the South Vietnamese Airforce flattened the city and its architectural wonders.

Surviving to this day, and the most impressive sight in Hue is the Citadel - a fortress city within many layers of towering walls. Each layer inward introduces a more sacred place than the last.