-A coastal area as an effective defense against Japanese pirate raiders

The reason to move Byeongyeong to Dongang(Gangjin) next to the sea was related to the defense against Japanese pirate raiders.
To effectively defend the coastal area against Japanese pirate raiders who would raid on the southwest coast from late in the Goryeo Dynasty, Joseon needed to concentrate its military strength on the coastal area.

Despite active measures to conciliate, the damage of Japanese pirate raiders continued. King Taejong reinforced military facilities in both inland and the coast and improved the military system to actively prepare for the raids of Japanese pirates.
In this process, Jeolla Byeongyeong was moved to Gangjin next to the coast.

Gangjin also had a mountain fortress wall in Mt. Suin as the back fortress. Suin Sanseong was built in the Goryeo Dynasty and used as a shelter late in the Goryeo Dynasty when Japanese pirates severely raided the area.
Since there was a beacon on the top of Mt. Suin which could report to Byeongyeong if the enemy was found in the adjacent fields became very productive, Gagnjin was a very good place of Byeongyeong.



-The location of a county(gun)-level fortress in history
It is assumed that this area was the seat of Dogang-hyeon.
Although Dogang-hyeon was demoted to hyeon according to the reorganization of an administrative district in the Goryeo Dynasty, it was Domu-gun in the Baekje Period and Yangmu-gun in the Unified Silla Period. Since there was strategic defense facilities fortress such as Suin Sanseong since early times, an old fortress was rebuilt and maintained to be used as a new one.

The establishment of Jeolla Byeongyeong in Gangjin was closely related to the improvement of local military system in the Joseon Dynasty. The Joseon Dynasty improved the national system to bury the military remains of Goryeo. It established the Yeongjin system that two or four military camps were built in every province and Cheomjeoljesa controlled adjacent troops.

The Jeolla area established Byeongyeong in Gwangsan-hyeon(near Songjeong, Gwangju) under the Yeongjin system and had four military camps. To defend Japanese pirate raiders, naval military camps were moved to the coast and finally Jeolla Byeongyeong was also moved to Gangjin to reinforce the defense system in cooperation with the army and the naval force.

Jeolla Byeongyeong in Gangjin was built by the military commander Ma Cheon-mok.
In Eulmyowaebyeon(Japanese invasion of Korea in 1555), Byeongyeong met with crisis. Although a damaged fortress was restored by the military commander Nam Chi-geun, it was destroyed by unexpected fire.
Then, it was totally remodeled and 1,800 people(Buddhist monks accounted for 2/3) were sent out to construct a building with 96 rooms according to 『Jeolla Byeongyeong Jungchanggi』.

On the other hand, there was constant controversy concerning the irrationality of the movement of Byeongyeong to Gangjin mainly on the aspect of geographic location. But, it was not accepted due to the strong need to defend the area against Japanese pirate raiders.

Meanwhile, the local army, following the Yeongjin system, became more systematic as the Jingwan system that reinforced inland defense.
Since defense focused on the coast under the Jingwan system, there was some discussion that Byeongyeong should be moved to Gwangju, Naju, or Damyang to reinforce the inland area. Some worried that the inland may put into danger because the army as well as the naval forces were mostly concentrated guarding along the sea or the coastal area.

In reality, Byeongyeong was once moved to Jangheung in the process of improving the military system in the 32nd year of King Seonjo(1599) immediately after Imjinwaeran(Japanese invasion of Korea in 1592).
However, there was a fierce conflict of interests among the locals and it was returned to Gangjin 6 years later. Jangheung residents suffered from frequent reception and Gangjin residents wanted to had Byeongyeong again.

Occasionally, after that time, there was a discussion on the movement of Byeongyeong by some administrators who was interested in local defense such as Oh Dal-un, born in Haenam, and Dasan Jeong Yang-yong. Oh Dal-un argued that Byeongyeong should be moved toDamyang, Gwangju, or Jangseong. However, his proposal was not accepted.

Since Imjinwaeran(Japanese Invasion of Korea in 1592) and Jeongyujaeran(Japanese Invasion of Korea in 1597), Joseon had kept the peace for long without the invasion of foreign power. Rather, it tried coping with the urgent political and social changes from within, local military camps did not show active changes more than the maintenance of the old status quo. Consequently, Jeolla Byeongyeong did not leave Gangjin until it was removed during the open port period.