Northern Border Defense of Goryeo in the 1050s

Timeline

1. 1051–1054Northern border beyond the Yalu River · GoryeoThe Cheonri Fortress (천리장성) and the Six Cities (Six Provinces) border-defense system built under Kings Hyŏjong and Chŏngjong continued to function in the 1050s; garrison troops and local strongmen jointly bore frontier watch duties, resisting raids by Jurchen tribes moving south.
2. 1056Northeastern Jurchen border · GoryeoIn 1056 Goryeo dispatched troops to repel an Eastern Jurchen invasion and destroyed more than twenty of their village strongholds. This military action was a landmark event of King Munjong's northern defense, showing that Goryeo still possessed considerable mobilization capacity after its 1018 victory over Liao.
3. 1057–1060Northern border beyond the Yalu River · GoryeoThroughout King Munjong's reign the line of control was pushed steadily northward; by his late years Goryeo territory had expanded to the Yalu and Tumen river basins, with numerous fortresses built to guard the new frontier. The border arrangements of the late 1050s provided a forward base for further operations against the Jurchens later in the 11th century.