Spatial structure and defensive strategy of Gaegyeong in the early Goryeo period

This study examines the spatial structure and defensive strategy of Gaegyeong, the capital of early Goryeo, prior to the construction of the Naseong outer wall. Following King Taejo’s relocation of the capital to Songak, Gaegyeong developed an urban structure that actively incorporated natural topography and reflected a synthesis of geomancy, Buddhism, and Confucian ideology. The Bal-eochamseong fortress was constructed in a mountain-based configuration that utilized surrounding ridges and waterways, securing substantial defensive capability without relying on artificial moats or extensive outer fortifications. In addition, the establishment of Buddhist temples under Kings Taejo, Gwangjong, and Seongjong contributed to the spatial expansion of the capital and functioned as political and ideological centers. In times of emergency, these temples also served as routes of military movement and as encampment sites. These findings demonstrate that Gaegyeong’s urban space formed a complex defensive system grounded in geography and temple networks, rather than solely in formal fortification. This study reinterprets the formative process and spatial characteristics of Gaegyeong’s early defensive strategy and offers a new perspective on the urban historical nature of the Goryeo capital.