King Jinheung’s Expansion
King Jinheung took the Han River basin, conquered Daegaya and pushed north-east into Hamgyeong, marking his conquests with steles.

Ethan Doyle White · CC BY-SA 4.0 · Source
Jinheung joined Baekje in retaking the Han River from Goguryeo (551), then seized Baekje’s share of the lower river (553). The Han basin was rich in people and farmland and, through Danghangseong, gave Silla its own sea route to China. The alliance with Baekje collapsed and King Seong was killed at Gwansan Fortress (554).
In 562 he conquered Daegaya, taking the whole Nakdong basin, and raised steles at Bukhansan, Changnyeong, Hwangchoryeong and Maunryeong. At home he made the hwarang a state institution, had Geochilbu compile the history Guksa (545) and built Hwangnyongsa.