Nine northeastern provinces of Yun Guan are the starting point for the dispute over the Kando Islands.

 윤Yoon Kwan's nine northeastern provinces are the starting point for the Gando dispute.˝ 1107 (the second year of King Yejong's reign in Goryeo) was the year when the territory of the Korean people expanded to Manchuria, north of the Tumen River, after the fall of Balhae. King Yejong of Goryeo ordered Yungwan to defeat the aftershocks in Northeast-myeon and install nine castles. This shows that Goryeo, which claimed to be a descendant of Goguryeo, actively expanded its territory to realize the national anthem. After the conquest of the aftershocks, Yungwan erected a monument commemorating the expansion of Goryeo's territory in Seonchunryeong, 700-ri north of the Tumen River. This monument was called Seonchunryeongbi because it was built in Yungwanbi or Seonchunryeong.   According to Goryeo Temple, after the conquest of the aftershocks, Goryeo organized the area into its own administrative systems, such as establishing a defense office in Yeongju-Bokju-Woongju-Gilju and Gongyeomjin. Among them, Gongjeomsin was established in the north of the Tumen River and occupied an important position in the territorial dispute between the end of Goryeo and the beginning of Joseon. However, only a year and five months later, in July 1109, Goryeo withdrew from the nine provinces. Kim Gu-jin, a professor of history education at Hongik University, said, "If you look at the records of the pioneering nine northeastern provinces, you can see that aftershocks refer to Goryeo as the "country of parents." It is explained that Goryeo's return of nine stars is a decision with various political implications. At this time, the nine castles that Goryeo returned to Yeojin are different from the nine castles first installed as Gilju-Youngju-Bokju-Hamju-Woongju and Sungnyeong-Tongtae-Jinyang-Sunhwajin. Professor Kim added, "Based on the records that the northernmost Gongjejin was missing and the Gongjejin was reduced to a fortress two years later in King Yejong's sixth year, Goryeo's territory is still north of the Tumen River even after the concession of the northeastern 9-star." After the Ming Dynasty was founded, China's claim for sovereignty over the north of the Tumen River began in earnest. After the fall of the Yuan Dynasty, the former Gongheompjin area was in the sphere of influence of King Taejo Lee Seong-gye, who was a great land lake as a residence of the Yeojin people, and there was no significant change in influence even after the founding of Joseon. In 1403, the third year of King Taejong of the Joseon Dynasty, the Yeongnakje of the Ming Dynasty sent Wang Ga-in to Yeojin in Manchuria. The intention was to incorporate the area by establishing a building surrounding the area and directly controlling the aftershocks. A serious incident occurred between Joseon and Ming Dynasty in which territorial disputes arose. Accordingly, Taejong ordered Haryun of Yeongchun Chugwansa Temple and Kwon Geun of Jichun Chugwansa Temple to investigate Yungwan's aftershocks and erected the monument (Seonchunryeong) on the border in Goryeo's Annals of King Yejong. In addition, while writing maps according to historical records, Kim Cheom, a kyepyeomsa, was sent to the Ming Dynasty to claim that the Yeojin people south of Gongheompjin were under the jurisdiction of Joseon. Eventually, in October of the 4th year of King Taejong's reign, the area south of Gongheompjin is recognized as Joseon territory. This is an event that revealed the sense of territory in the early Joseon Dynasty to inherit the old territory of Goryeo. The perception that the public experiment team is the boundary of our territory reaches its peak during the reign of King Sejong. If you look at the Annals of the Joseon Dynasty, you can see Sejong's interest in the nine northeastern provinces of Yungwan. If you look at Hamgil-do's episode of Sejong Silokjiriji, 준Junryeong rises and falls from Baekdusan Mountain to Cheolryeong in the south, so I am positive about 1,000 ri. The north was along the land of the barbarians, and the northeast boundary of Joseon is not the Tumen River by describing it as about 1,700 rida from Cheolryeong in the south and Gongheomjin in the north." Sejong orders Kim Jong-seo, a provincial governor of Hamgil-do, to check the location of the experiment team and report it. 그Can anyone find the inscription? How is the rain now? If the road is blocked and it is not easy to detect, think of a way to detect it without harm, and tell them, "What castle is it now, and which side of the camp is it, and how many commercials are there?"˝ This sense of territory of King Sejong was faithfully reflected in the map made at the time. If you look at the Dongguk Map completed in the 9th year of King Sejong's order, the public officials and Seonchunryeong are clearly marked north of the Tumen River (see photo). Dongguk Map is Korea's first practical map. Therefore, it can be seen that the producers of "Dongguk Map" directly checked the location of the public experience team and Seonchunryeong Pass. In this regard, our historical description, which follows the theory of the location of Hamheung Plain in the northeast nine provinces by some Japanese scholars, should be reviewed. However, Sejong and Kim Jong-seo, who were trying to restore their territory with the aim of the public experiment team pioneered by Yun Gwan, did not cross the Tumen River and stopped. And the nine northeastern provinces of Goryeo and the monument to Seonchunryeong become a forgotten history. #I often think that we were a pretty good country until the early Joseon Dynasty (16th century).