Northern Border Defense of Goryeo (c. 1028)

Timeline

1. 1027–1028Six Districts · Northern Korean PeninsulaUnder Hyeonjong, the Six Districts (Yukbu Bangseong) border military-administrative zone was reorganized: garrison forces were reinforced, fortresses repaired, and control over local subordinate tribes tightened, building a first line of defense against the southward advance of northern nomadic powers.
2. 1028–1029Yalu River · China–Korea borderBeacon fires, passes, and military-agricultural colony outposts were added along the line from the Yalu River to the Cheongcheon River, forming a defense-in-depth system. This both guarded against renewed Liao invasions and curbed Jurchen raids on Goryeo's border.