When and How Goguryeo Advanced Into Chungju

In this paper, it has been understood that the value of the Chungju region was based on its location on a straight road connecting Pyongyang, Hanseong and Gyeongju. Goguryeo used Pyongyang as a base for its southern strategy during the reign of King Gwanggaeto. If Goguryeo occupied Hanseong, the importance of Chungju would increase, but if not, it would have secondary value. On the other hand, Baekje, which was in Hanseong and tried to counter Goguryeo through an alliance with Silla, would have needed Chungju, a channel to connect with Silla, and therefore would have tried to secure it. Goguryeo entered Chuncheon in the Bukhan River basin, connected to Silla through Hongcheon, Wonju-Hoengseong, and the Namhan River basin, and in some cases conducted military operations. This does not mean that Goguryeo could not enter the Chungju area or that such a fact would not have happened. Basically, such a composition was formed, and it is thought that this is consistent with the remaining archaeological materials to some extent. After the fall of Hanseong, it was Silla that exerted the most influence over Chungju. In other words, there was a temporary power vacuum until Goguryeo built Hanseong as its southern base. Goguryeo attacked Baekje in a straight line to Namseonggolsanseong Fortress in Cheongju and attacked Silla through existing traffic routes. After that, Goguryeo attacked Salsuwon, which is designated as Dalcheon basin, and Usanseong, which is designated in Chungju. It is judged that this is largely due to the active management of Hanseong and attention to the value of the Chungju region. However, it was Silla who considered the Chungju area more important than anyone else. This is because it was the most important window to advance to Baekje and Goguryeo, which occupied the Han River basin. It must have been for this reason that Silla, who had secured the Chungju area in the mid-6th century, called it Gukwon and valued it.