The 1728 Musin-ran and the Reorganization of the Defense System at Pukhansansŏng: Reflections of a Crisis Experience

Following Chosŏn’s defeat in the Pyŏngja Horan (Manchu Invasion of 1636) in the early 17th century, Qing interference limited military reorganization from the northwestern frontier to the capital city of Hanyang. As a result, until the late 17th century, Chosŏn’s capital defense strategy primarily relied on retreating to designated sanctuaries such as Kanghwa-do and Namhansansŏng in times of crisis. However, with changes in both internal and external conditions around the turn of the 18th century, a gradual restructuring of this sanctuary-based system became increasingly necessary.In response, during the latter part of King Sukchong’s reign, new sanctuaries—Pukhansansŏng and T’angchundaesŏng—were constructed in the Pukhansan area, which lay near the capital and at the terminus of the Ŭiju route connecting the capital to the northwestern frontier. Under the command of the Kyŏngnich’ŏng’s Kwansŏngso (Construction Office), a defense strategy was established in which the Samgunmun and the Ch’ongyungch’ŏng were tasked with guarding these fortifications. At the same time, military supplies were stockpiled, effectively completing the initial stage of the regional defense system.The defense system established in the Pukhansan area during the latter part of King Sukchong’s reign was later tested in actual combat. During the Musin-ran rebellion of 1728 (the 4th year of King Yŏngjo), when the rebel forces attempted to invade the capital, troops from the Kwansŏngso, the Samgunmun, and the Ch’ongyungch’ŏng were mobilized to T’angchundaesŏng and Pukhansansŏng. Pukhansansŏng served as a key military base, providing both troop deployment and a supply center for gunpowder, bullets, and other munitions, thereby playing a critical role in establishing the outer line of defense for the capital. The fortress’s strategic role as an outer defense stronghold—rather than merely a sanctuary—was reaffirmed. However, this episode also revealed serious limitations of the existing defense system, including confusion in the chain of command, insufficient fortress infrastructure, and a lack of military supplies.After the Musin-ran, the defense of the capital was strengthened, and during King Yŏngjo’s reign, the Ch’ongyungch’ŏng was placed at the center of a unified military structure in the Pukhansan area. Throughout the late 18th century, continued efforts were made to reinforce the region’s defense system. During this period, the management and operation of military resources—including grain reserves, gunpowder, and firearms—were reorganized, and the reconstruction of T’angchundaesŏng was carried out. The organization and deployment of Ch’ongyungch’ŏng troops were also improved. As a result, the outer defense of the capital, centered on the Pukhansan region, became more robust and stable.