Background
He was the third son of the eighth king Sindae and the younger brother of the ninth king Gogukcheon, who died without an heir.
He was the third son of the eighth king Sindae and the younger brother of the ninth king Gogukcheon, who died without an heir.
Upon Gogukcheon"s death, his queen Lady U supported Sansang"s claim and had him placed on the throne. She then became Sansang"s queen. This indicates that the custom of Levirate marriage was still practiced in Goguryeo, but also demonstrated Lady U"s power in court.
Balgi, older brother to Sansang, led a rebel force attacking the capital, gaining military support of Chinese faction.
Sansang"s Goguryeo was later attacked by Han Dynasty China and forced to submit to the Han Dynasty. In 209, the capital was moved to Jian by warlord Gongsun Kang of the Han Dynasty.
In 217, he granted refuge to a thousand families from the Liaodong region. In the eleventh lunar month of 208, the king chased a sacrificial boar to the village of Jutongchon, where he met a young woman and spent the day with her.
The queen heard of this and sent royal forces, failing to kill her owing to her assertion that she conceived.
The woman gave birth to a son and became a royal concubine. The son was made crown prince in 213 and later became King Dongcheon. Sansang died during 227, the 31st year of his reign, and was buried in Sansang-neung.