The Gwansanseong Fortress War is the most widely known international war of the Three Kingdoms period. As is well known, the basic reason for the outbreak of this war is the backlash caused by Baekje's loss of the Han River basin. However, it is significant that Okcheon was the first target of Baekje's anger, which reached its peak after losing the lower reaches of the Han River due to Silla's betrayal. It is thought that Baekje wanted to attack Okcheon, which was close to the Nonsan area, which was almost like a front yard, and first eliminate the dagger that seemed to be sticking at their necks.
The Gwansanseong Fortress War was not temporary, it appears to have started in July and ended around December. In the early stages of the war, the situation was favorable to Baekje, to the extent that Gwansanseong Fortress was taken and Guttamorasae was built. It seems that the Guttamorasae built by Yeochang can be assigned to the Shimcheon-myeon or Iwon-myeon area. Afterwards, the war reached a stalemate and King Seong, who had rushed out to encourage Yeochang's army, which was in trouble, was killed on the road, and this war had a huge impact on the future of the three kingdoms. It seems that King Seong was killed in an area close to Okcheon because Yeochang's main camp retreated to the area around Gwansanseong Fortress.
Looking at the fact that Gaya was destroyed not long after the Gwansanseong Fortress War, we can guess the aftermath of this war. The Gwansanseong Fortress War not only brought about the destruction of Gaya nearby, but was also a decisive war that decided the fall of Baekje and the survival of the three kingdoms in 660, and Okcheon was an area in the center of that whirlpool. The Okcheon area is a place with a richer historical narrative than any other place, including the Gwansanseong Fortress War that decided the fate of the Three Kingdoms, the tragic death of King Seong, and the border of Jera(Baekje+Shilla), which could be called the Three Kingdoms’ version of the DMZ.