Gangdong 6 weeks
Gwangdong is the territory of Koryo-han-myeon, which was recognized as a sovereignty by Seo during the first invasion of Yonara in 993, when it was discussed with Soon-yong of Yonara. This place, which was geographically important point of military thought and transportation, was a place where Ryjin resided after Goryeo Dynasty and became a great obstacle to the advancement of Goryeo in the northern part of Goryeo. Goryeo occupied 6 weeks of Goryeo without intervention of Yonara after Sarah. The six provinces of Gangdong are located in the east of the Yalu River, which is the top of the Goryeo Dynasty of the Koryo Dynasty.