[1] He became king upon Chaekgye's death in 298 when he was killed in battle during the 13th year of his reign.
The Samguk sagi records that "from his youth he was bright and intelligent, and in his performance of rites he was bold and upright.
[2][3] He continued to wage war against the Chinese Lelang commandery whose forces had killed his father.
According to the Samguk sagi, the governor of the commandery thereupon sent an assassin who killed him.
[4][3][5] Samguk sagi: With the death of Bunseo, a descendant of the 8th king Goi, the rival royal line descended from the 5th king Chogo, retook the throne, except for the brief rule of Bunseo's son Gye as the 12th king.