King Anwon’s name is Boyeon, and he was the younger brother of King Anjang, the 22nd monarch of Goguryeo. Boyeon was loved by the king, who frequently called his younger brother into the royal court. The king had no son, and he regarded Boyeon as his successor. When the king died without an heir in 531, Boyeon took power to become King Anwon. It is said that he was very tall and generous.
When the Chinese dynasty of Northern Wei was divided into two states, namely, Eastern Wei and Western Wei, in 534, King Anwon displayed multilateral diplomacy and engaged both Eastern Wei and another Chinese state of the Liang Dynasty in order to maintain stability. In the southern part of the Korean Peninsula, the two Korean kingdoms of Baekje and Silla formed a military alliance and strengthened national power to confront Goguryeo. Based on balanced peace, King Anwon ruled over a relatively peaceful period, at least diplomatically. The only military conflict during the king’s reign occurred in 540, when Baekje attacked the Usan Castle. As the Baekje forces surrounded the castle, the Goguryeo fortress was put in a defensive corner. The king quickly sent 5,000 troops, which carried out a surprise attack against the enemy from behind, to save the castle on the verge of collapse. Goguryeo managed to fend off the enemy forces, but it couldn’t afford to counterattack due to many problems within the nation.
Domestically, the kingdom suffered from various natural disasters such as floods, earthquakes, thunderstorms, a severe drought, famine, infectious diseases and even a large swarm of locusts. It also experienced abnormal weather conditions, like hail in summer, for many years. These problems plagued the kingdom throughout the king’s reign.
Worse yet, a power struggle began in the later years of the king’s life. As the king’s first queen had no children, the second and third queens fiercely competed to make their own son the crown prince. The noble class was split into two forces, with each faction supporting its favored prince. The bitter aristocratic factionalism developed into violent armed clashes that claimed thousands of lives and resulted in social unrest. It is assumed that King Anwon was killed during the chaotic battles between the opposing aristocrats. The king died in 545, ending his 14-year rule.
The political turmoil and internal division before and after the king’s death significantly weakened royal power. From this period, Goguryeo started on the downward path.