Gongju was geographical key position surrounded by Charyeong Mountain Range and Geumgang river. However, Gongju of early Joseon period was not focused as military key position although defense facility of border area of the North and the coast of the South. But, geographical and socio-economic condition of Gongju was focused during the Japanese invasion of Korea, mountain fortress was established and then, it became defense mountain fortress, the base of Chungcheong-do. This thesis concentrated on the investigation of actual status of military organization and mountain fortress management of Ssangsu mountain fortress in late Joseon period from a military angle.
Gong mountain fortress abolished in early Joseon period was established in the 36th year of Seonjo(1603). In the year, government transferred gamyeong in Gong mountain fortress and audit-centered administrative system and military system were unified. In the process, auditor 柳根 extensively established Gong mountain fortress which was the base defense facility during the Japanese invasion of Korea. The position of Gong mountain fortress was enhanced while its name was changed to Ssangsu mountain fortress rightly after the utilization of refuge place of Injo during the rebellion of 李适. And, in the 24th year of Injo(1646), it was reestablished due to the rebellion of 安益信.
Ssangsu mountain fortress became gwanbang of Chungcheong-do from military function after 100 years of the establishment, the 29th year of Sookjong(1703). In the period, regional defense system was much strengthened with appearance of 海防論as foreign situation was unstable.
In the situation, 3,000 sokogun soldiers under Chungcheong military were arranged in Ssangsu mountain fortress and based on the military strength, military organization of Ssangsu mountain fortress was prepared based on Soko law. In addition, for the director of the military strength, 巡營中軍 who was dangsang of jeong3pum was nominated.
Through the process to secure military strength of Chungcheong gamyoung in the 17th century, about 8,000 people were arranged to Ssangsu mountain fortress. But, while foreign situation was stable after the 18th century, government arranged military soldiers to the center and from them, collected some financial sources. In addition, most of the soldiers belonged to the regional military institution were becoming 納布軍化. In the stream of military policy, most of the military strength of Ssangsu mountain fortress became nappogunhwa.