King Goujian of Yue vs Sansang of Goguryeo

King Goujian of Yue defeated the invading Wu army at Zuili, mortally wounding King Helu of Wu. This victory marked Yue's emergence as a rival to Wu, but also provoked a future Wu invasion that would nearly destroy Yue.

King Fuchai of Wu besieged Goujian's forces at Mount Kuaiji after defeating Yue. Goujian surrendered and became a hostage in Wu, enduring humiliation as a servant. This event began his period of hardship and eventual revenge.

After returning from captivity, Goujian slept on brushwood and hung a gall bladder to taste daily, symbolizing his determination to never forget his humiliation. This practice became a Chinese idiom for perseverance and fueled his long-term plan to conquer Wu.

Goujian launched a successful invasion of Wu, capturing its capital and forcing King Fuchai to commit suicide. This conquest ended Wu's existence and made Yue the dominant state in the region. Goujian then became a hegemon among the Spring and Autumn states.

Upon ascending the throne, Sansang married his deceased brother Gogukcheon's widow, Queen U. This marriage was controversial but helped consolidate his claim to the throne and maintain continuity with the previous reign.

The Han dynasty of China launched a major invasion of Goguryeo, capturing several border fortresses. Sansang led the defense, ultimately repelling the invasion but suffering significant territorial losses in the Liao River region.

After the Han invasion, Sansang ordered the fortification of Gungnae Fortress and other key defensive positions. He also reorganized the military command structure to better respond to future Chinese threats.