In the late 14th century, the Ming dynasty expelled the Yuan Dynasty from the central districts of China. Because of this historical event, appeared much chaos in many areas of the Yuan dynasty's territory, including the central districts of China. An...
In the late 14th century, the Ming dynasty expelled the Yuan Dynasty from the central districts of China. Because of this historical event, appeared much chaos in many areas of the Yuan dynasty's territory, including the central districts of China. And the Liaodong area that adjoins Goryeo's north border was in chaos too. In those days, Goryeo(高麗) was in the reign of King Kongmin(恭愍王), and King Kongmin entrusted reforms of Goryeo's domestic affairs to Shin-Don(辛旽) after regressed from aggressive the anti-Yuan policy that progressed in early period of his reign. But the relationship between Goryeo an Yuan was still not smoothed. And add to that, reforms of Goryeo's domestic affairs that progressed by Shin-Don who entrusted him with that task was sliding into the breaking point. In this domestic and foreign situation, the chaos brought on by changing period of Yuan and Ming was the chance which can tip the scales.
The military expedition to Dongnyongbu(東寧府) that operated at this moment was the historical event which Goryeo attacked the Ulla mountain fortress(亐羅山城/兀剌山城), the Liaoyang castle(遼陽城) and surrounding areas of them in the Liaoynag area two times at the early and late of 1370(the 19th year during the reign of King Kongmin). And it was operated under cover of a temporary political vacuum in Liaodong area which caused by changing of the domination power of the central districts of China.
Originally, Dongnyongbu had lost its essence, and just remained formally after 1290. But in changing period of Yuan and Ming, Ki-Saeintimur(奇賽因帖木兒) occupied the Liaoyang castle as his base and trying to construct his fief which the name of Dongnyongbu as its pretext, under cover of chaos at that period. As a result, Dongnyongbu became a threat to Goryeo and King Kongmin.
At first, King Kongmin claimed to stand of the anti-Yuan policy from the early time of his reign. This policy has double sides. In external side, it aimed to restore the political independence from interference of Yuan. International trend which decline of the Yuan dynasty was its opportunity. At the same time, in domestic side, it aimed to reform Goryeo's domestic affairs and to strengthen royal authority in accordance with Goryeo's golden age. In this case, anti-Yuan policy was the justification of this domestic purpose. The military expedition to Dongnyongbu was the symbolical event of the anti-Yuan policy which progressed in the late of King Kongmin's reign. And this expedition shows the characteristic of anti-Yuan policy that its double sideness. Dongnyongbu which Ki-Saeintimur ruled was regarded as pro-Yuan group. But in domestic side of Goryeo, his fief has enough potential that could become serious threat to the throne of King Kongmin. Therefore, the meaning of attacking Dongnyongbu has double side too. In external side, this expedition was an action which clarifed Goryed's anti-Yuan stand internationally. And in domestic side, it was an action for defend the throne of King Kongmin and strengthen royal authority.
Through the success of this expedition, Dongnyongbu which Ki-Saeintimur ruled was collapsed. And as a result, King Kongmin could remove threat to his throne. He also gained results following two things. First, many people defected to Goryeo and Goryeo's prestige was enhanced in Liaodong area by this success. Second, it seems to be that King Kongmin could take the initiative in the domestic political situation and also gave added momentum to his anti-Yuan policy and attempt to domestic reform, too. On the other hand, He also gained results following two things about in domestic military system. First, he installed five Manhoboo(萬戶府) in the northwest area of the national territory, and placed Ikgoon(翼軍) under the Manhoboo. As a result, he secured new military manpower which for both soldier and farmer. And he could strengthen royal sovereign power to not northwest area of the national territory but also a manpower in that area. Second, he modified the Dotongsa(都統使) system and established a permanent Dotongsa system. As a result, he could impose restrictions on tendency to reinforcing the private army. And he could strengthen his prerogative of supreme command.
In brief, the military expedition to Dongnyongbu in the reign of King Kongmin was almost triggered by serious external threat to his throne. Through the success of this expedition, King Kongmin expelled external threat effectively. On the other hand, he strengthened his domestic political leverage. And he could install the system for strengthen royal prerogative of supreme command at the same time.
But King Kongmin closed his reign by unforeseen assassination. And because, his reform was stopped in the middle of its progress. This is the one of limits in his reform policy. And it is the limit of the meaning of this expedition at the same time, too.