Before and during the Goryeo Dynasty, naval forces were unified with the army and did not have a separate command structure. However, with the establishment of the Joseon Dynasty, the naval forces were created as an independent branch of the military. When examining the background of why the Joseon government, shortly after its founding, established the naval forces as a separate military branch, one cannot ignore the threat of foreign invasions, particularly from Japanese pirates known as ‘Waegeu.’ The Korean Peninsula, surrounded by the sea on three sides due to its geographical characteristics, had always been vulnerable to external invasions via the sea. However, the nature of Japanese pirate invasions changed significantly after 1350 (the reign of King Chungjeong). After 1350, the 'Waegeu of Gyeongin' started to organize on a larger scale, and Goryeo was defenseless against their raids. In response, the Joseon Dynasty not only established the naval forces as an independent branch to counter the Waegeu threat but also focused on the construction of naval vessels.
The Joseon government made efforts to create a strategic plan for dealing with the Waegeu threat, including the establishment of naval bases and dockyards to ensure rapid deployment of naval forces.
Jeolla Province was located along the route of Japanese pirate invasions and was frequently targeted due to its abundant maritime resources. To prevent the incursions of Japanese pirates into the western sea, Jeolla Suyeong (naval command) was established in Okguhyeon (present-day Gunsan). Okgu was strategically located at the juncture of the sea and was an ideal position for naval transportation.
As Japanese pirate activities increased during the reign of King Taejong, the central government began searching for a suitable location to station military ships. Okgu's location at the northernmost part of Jeolla Province created a problem in defending the southwestern coast against pirate incursions. Therefore, Jeolla Suyeong was relocated from Okgu to Daegulpo in Muanhyeon. Muanhyeon, deep in the inland, had the advantage of being concealed and able to easily detect Japanese pirate ships entering the coastline, but it could only provide passive defense.
To address the issue of the endless expansion of naval forces and the placement of military ships in remote areas, the solution was to increase the efficiency of naval forces by enhancing the boundaries, operational range, and mobility of the naval forces. In other words, there was a shift from passive defense to an aggressive defense strategy. To implement this aggressive defense strategy, it was necessary to relocate Jeolla Suyeong, which was tasked with defending the southwestern coast. During this period, there was a trend of relocating military bases located inland to coastal areas, which was seen throughout the country. Jeolla Suyeong also moved from Daegulpo, which was located inland, to Hwangwongot in Haenam, adjacent to the coast.
Upon settling in Hwangwongot, Jeolla Suyeong was divided into Usuyeong (Right Naval Command) and Jwasuyeong(Left Naval Command) due to frequent Japanese pirate invasions such as the Saryangjin Incident and Eulmyo Incident.
The relocation and organizational changes in the naval forces were related to the nature of the Waegeu threat, and this study examined the process of change in Jeolla Usuyeong based on the movement of Waegeu.
Understanding the shifting positions of Jeolla Usuyeong allows us to explore the significance of maritime defense strategies during that time.