The competition between Silla and Baekje over the Han River basin in the mid-6th century: Focusing on the cooperation and conflict of 548-554 year
Authors:   HUFS Institute of History and Culture, Choi Sang-ki 
Published: December 2023

In the mid-6th century, various incidents occurred in the process of the three countries competing for the Han River basin. The Battle of Doksanseong(獨山城), which took place in 548, was an incident in which Silla(新羅) dispatched salvation army after Goguryeo(高句麗) attacked Baekje(百濟)'s Doksanseong. Doksanseong was located in Yesan, Chungnam. In 541, Silla and Baekje formed a friendship, so they were able to dispatch the salvation army. The Battle of Dosalseong(道薩城) and Geumhyeonseong(金峴城), which took place in 550, was an incident in which Silla took two es independently during the clash between Baekje and Goguryeo. Geumhyeonseong was originally a Baekje castle, but it was occupied by Goguryeo, so Silla rejected Baekje's request to return Geumhyeonseong based on this, and even obtained Dosalseong based on Geumhyeonseong. Baekje targeted Dosalseong to prevent Silla's expansion, but it was geographically isolated as Silla took over Geumhyeonseong. Baekje inevitably handed over the Dosalseong to Silla, which was also influenced by diplomatic considerations to attract Silla to Goguryeo's invasion of Goguryeo. In 551, Silla and Baekje invaded Goguryeo. It was Baekje that led the invasion, and both countries seem to have moved forward around March 551. Silla troops were dispatched from Chungju, and it is presumed that they moved with Baekje troops until they attacked the area downstream of the Han River. When Baekje abandoned the area downstream of the Han River in 552, Silla first took over the Hanseong(漢城) area, and in 553, the operation of Shin-ju(新州) was begun. In particular, based on the improvement of relations with Goguryeo, it dominated the entire area downstream of the Han River from the beginning. Baekje recognized the improvement of relations between Silla and Goguryeo between September 551 and May 552, and the incident that occurred in the process was the Battle of Baekhabya(百合野) between Baekje and Goguryeo. Considering the situation at that time, it should be considered that the Battle of Baekhabya was between September 551 and May 552. After successfully targeting the lower part of the Han River, Baekje proposed a further attack on Goguryeo, but had to engage with it alone as Silla rejected the offer. In the meantime, Silla, which improved its relationship with Goguryeo, threatened Sabi Castle(泗沘城) with military force in Sang-ju(上州), and Baekje had no choice but to give up the area downstream of the Han River and return Baekje troops. In 553, King Jinheung(眞興王) married the King Seong(聖王)'s daughter. King Seong proposed marriage to hide the intention of invading Silla, and King Jinheung attempted to defeat Baekje's will to invade and pass the responsibility of the war on King Seong by carrying out a mutual inviolability pledge with the King Seong. The Campaign of Gwansansung(管山城) ran from July to December 554, the first battle of which was the Battle of Jinseong(珍城) in September. Silla troops tried to prevent Gaya and Baekje troops from gathering here, but failed. The Battle of Ungcheonseong(熊川城) broke out in October, as Silla, which was on the defensive due to the defeat of the Battle of Jinseong, called on Goguryeo to attack Baekje. Be wary of Goguryeo's movement, Baekje wanted to end the Campaign of Gwansansung as soon as possible. At the time of his death, it is possible that the troops led by the King Seong were 5,000 standing soldiers stationed in Sabi Castle. King Seong wanted to confirm the victory by sending additional reservists at a time when the fighting power of the Baekje Army was reduced due to continued fighting. However, when King Seong, who was moving forward with troops, died along the way, the Campaign of Gwansansung ended with the defeat of Baekje.