Based on the popular novel by Jin Yong Kam Yung (aka Louis Cha). He also wrote Legend of the Condor Heroes and Return of the Condor Heroes. The Heavenly Sword and Dragon Sabre takes place during 14th Century China during the Mongolian Yuan Dynasty, roughly 100 years after the events of Return of the Condor Heroes. After decades of struggles, famine, and bitterness which the Chinese citizens blamed on the Yuan Dynasty's misgovernment, the Martial Arts sects have begun to rebel. Prince Ruyong asks Cheng Kun, a Shaolin monk with an ulterior motive, for a plan on how to deal with the rebels.
"The wielder of Heavenly Sword and/or Dragon Sabre rules the world."
This well known legend in the Martial Arts community is the impetus for the tale of Zhang Wuji. The story begins with how his parents met (episodes 1-3), then tells his trials as an adolescent (episodes 4-8), proceeds to relate his rise to prominence (episodes 9-23) and reveals the secret behind Heavenly Sword and Dragon Sabre (episode 23), and ends with the confluence of Wuji's love life, the Martial Arts sects' long standing grudges, and cruel fate.