高句麗와 渤海의 城郭운용방식에 대한 기초적 검토 -延邊地域분포의 성곽에 대한 이해를 겸하여-

Abstract

In general, it has been believed that Koguryeo fortresses were built mostly on hills; however, in Yeonbyeon(Yanbian) there exist the remains of many Koguryeo fortresses built on flatland. Accordingly, one must study the characteristics of both types of Yeonbyeonfortresses, hill and flatland, to fully understand their functions. Most fortresses, including those in Yeonbyeon, were repeatedly rebuilt, making it difficult to determine when they were first constructed. Many Yeonbyeon fortresses are thought to have been built during Balhae, yet there is little evidence to show why Balhae should build so many. Fortress construction presumes a need to reinforce defense against hostile powers, thus Yeonbyeon fortresses at major points are not necessarily a product of flourishing construction during Balhae, but rather a reflection of Koguryeo times. To better understand the distribution and the characteristics of Koguryeo fortresses in Yeonbyeon, this paper focuses on traffic routes rather than construction periods. In particular, Chaekseong (Shancheng) was able to grow as a governing center with a route to the Guknaeseong. Along this route, other fortresses were constructed linking the tworegion and provided support in emergencies. A major road, henceforth described as ‘the route toward Okjeo,’which links the center of Koguryeo and Yeonbyeon, passes through the present Jian and Linjiang, the mountain areas of Fusong and Antu, and the coast of Buerhatonghe to the west. This finding is supported by the Abrok route used during Balhae and the present state road linking the east and west of Yeonbyeon. The site of the Dongqing fortress located in the area entering Antu from Fusong shows ‘the route toward Okjeo’was an arterial road linking the Guknae Fortress and Chaekseong, and fortresses were constructed at strategic points along the this route. Therefore, ‘the route toward Okjeo’was constructed in Yeonbyeon during Koguryeo Kingdom and had many fortresses to link and to maintain the route. This paper also examines the Yeonbyeonjangseong (Yanbianchangcheng), the largest defense facility in this area, which some argue was built by the Koguryeo Kingdomto face north. By facing north, the fortress could not have defended the area, and one must presume it faced the south and was not of Koguryeo Kingdom construction. On the other hand, the Koguryeo Kingdom’s fortresses in Yeonbyeon were confined mostly to flatland. Therefore it is reasonable to assume that Koguryeo’s fortresses in Yeonbyeonfunctioned to rule internally, while other fortresses in central area of Koguryeo were constructed for political and military purposes. This fortress style in Yeonbyeon later changed with the advent of grand hill structures for residential purposes during peaceful times. Thereby, the general operating system of fortresses during the mid and late Koguryeo Kingdom applied in Yeonbyeon, that is, the combination of hill and flatland fortresses. This paper omits examination of the circumstances and dates of these changes. Along with Undusanseong, in the Duman River’s southern basin, Jodongsanseong in the northern basin was the Koguryeo fortress constructed to link the north and south of ancient Okjeo. Such a location of Jodongsanseong and its correspondence with Undusanseong during the Koguryeo Kingdomdemonstrates the existence of a traffic route linking Yeonbyeon to the east coast of present Hamgyeong Province. Along this route, with the Duman River between, the part linking Guknae Fortress and Chaekseong was constructed first, and the part linking Chaekseong to the east coast of Hamgyeong Province via the Duman River was built later. Therefore, one can assume that Chaekseong during the Koguryeo Kingdom functioned not only as a strong point in Yeonbyeon but also as an outpost to advance toward the east coast of Hamgeyong Province. Accordingly, one should consider that Koguryeo fortresses in Yeonbyeon were aimed at securing the link to the east coast of Hamgyeong Province.