evidence: Yalu/Amnok River borders, but suggests some Chinese dissatisfaction about the status of the border with North Korea in the territory between the two rivers. [...] Yalu/Amnok River into the current territory of the DPRK. [...] China and Choson then made these two rivers the border between their countries is inaccurate. According to Korean sources, during the reign of King Kongmin, the Koryo government established counties and prefectures for local administration and defense structures in the Amnok (Yalu) River area so that it controlled territory south of the Amnok (Yalu) River. Later, during the reign of King Sejong in the first half of the fifteenth century, the Choson government defeated Jurchen communities and then established four counties in the Amnok (Yalu) River's upstream area and six military garrisons in the downstream area of the Tuman (Tumen) River. In this way the