This study aims to examine the transformations of Sŏwŏn’gyŏng and the dynamics of local society during the Late Unified Silla–Early Koryŏ period. Following the wars of the Three Kingdoms unification, Sŏwŏn’gyŏng was established in the Ch’ŏngju region, and in the late Silla period it was reorganized as Sŏwŏn-bu (西原府), modeled after the Tang dynasty’s yusobu (留守府) system. With its reorganization from sogyŏng into a bu, its status was elevated to that of an independent administrative unit separate from chu (州), and its administrative territory is presumed to have been expanded accordingly. The rebellion of Kim Hŏn-ch’ang in 822 is noted as a critical turning point in this reorganization.
In the late Silla period, successive natural disasters and the weakening of state authority over the provinces led to the collapse of the Silla polity, and autonomous forces equipped with military organizations emerged in various regions, including Ch’ŏngju. With the decline of the kolp’um system (骨品制), Sŏwŏn’gyŏng/Sŏwŏn-bu lost its meaning as a secondary capital (副都) inhabited by the ruling elite under the Silla hierarchy. When Kungye (弓裔) seized the Ch’ŏngju region, it was reorganized as Ch’ŏngju (靑州), though its character as a traditional major settlement appears to have been maintained. In the Ch’ŏngju region, numerous native surnames rooted in the region (土姓) were present, and in the early Koryŏ period the local-based forces held higher official ranks than those in other regions.
The numerous local magnate forces (豪族) of Ch’ŏngju were divided into capital-based and local-based groups when Kungye forcibly relocated the inhabitants of Ch’ŏngju to Ch’ŏrwŏn. These two groups, depending on their respective interests, adopted different stances toward the central government and often engaged in mutual checks and confrontations. After his enthronement, Wanggŏn (王建) suppressed successive rebellions or plots of rebellion and personally visited Ch’ŏngju in an effort to secure the region firmly. Among the capital-based forces of Ch’ŏngju who supported Wanggŏn, the Ch’ŏngju Kim clan exercised influence over local society by leveraging their political position and marital ties with the royal family, thereby reorganizing the local-based forces around themselves. Through the process in which the Ch’ŏngju Kim clan established dominance in local society, the Ch’ŏngju region was fully integrated into the ruling system of Koryŏ.