King Seong of Baekje

Timeline

1. 523–538Ungjin (former capital, present-day Gongju, South Chungcheong Province) · BaekjeIn 523 he succeeded his father King Mu and took the throne, facing continued southern pressure from Goguryeo. He actively reorganized domestic affairs, strengthened diplomatic ties with the Liang dynasty, and introduced advanced institutions. In 538 he moved the capital south from Ungjin (present-day Gongju) to Sabi (present-day Buyeo) and changed the state's name to 'Nambuyeo' to restore Baekje's prestige.
2. 538–551Sabi (present-day Buyeo, South Chungcheong Province) · BaekjeAfter moving the capital, he carried out administrative reforms in the new capital Sabi, establishing a five-ministry, five-region system to strengthen central authority. In 538 he sent envoys bearing Buddhist statues, scriptures, and monks to the Yamato court in Japan, formally transmitting Buddhism to Japan and leaving a profound impact on East Asian cultural history. Throughout the same period he maintained close diplomatic and cultural exchanges with the Liang dynasty.
3. 551–554Gwansanseong (near Ochang, North Chungcheong Province) · Baekje–Silla borderIn 551 he allied with Silla's King Jinheung to attack Goguryeo, recovering six commanderies along the lower Han River; however, in 553 Silla broke the alliance and seized by surprise attack the territory Baekje had newly gained. In 554 King Seong personally led reinforcements to relieve the besieged crown prince, but was ambushed by Silla forces at Gwansanseong, captured and beheaded, dying heroically for his state; Silla thereby consolidated its control over the Han River basin.