In Korean history, righteous armies (), sometimes translated as irregular armies or militias, mainly refers to civilian armed organizations that were spontaneously formed to fight against foreign invasions, such as the Imjin War and the Qing invasion of Joseon. The Righteous armies under the Korean Empire also followed this trend; they did not have proper weapons, but fought against Japanese imperialism.

Japanese invasions of Korea

The righteous armies were an irregular military that fought the Japanese army that twice invaded Korea during the Japanese invasions of Korea (1592–1598). Righteous armies were most active in the Jeolla Province in the southwestern area of Korea. Righteous armies included peasants, scholars, former government officials, as well as Buddhist warrior monks. Righteous armies were important during the war as a significant portion of the expected government organized resistance had been destroyed in Gyeongsang and Chungcheong Provinces by the Japanese forces at the outset. The natural defenders had been defeated and the residue had been called north to help protect the fleeing king. Many of the district officers had obtained their commissions through bribery or influence, and were essentially incompetent or cowards, evidence in their own performance and of their units in the early days of the conflict.

This kind of resistance was totally unexpected by the Japanese. In Japanese warfare, civilians would simply submit where their leaders fell. However, the Japanese were shocked upon learning that the Korean people were forming organized resistance against them. Japanese strategies were based on the premise that the people of Korea would submit to them and assist their supply line by giving their food. However, this was not the case and righteous armies continued to interrupt the Japanese supply line. People's voluntary resistance movements were one of the major reasons why Japanese invasion was not successful.

Righteous army was organized and led by seonbi, who were Confucian philosopher and mostly trained archers. Political positions, social status, and economic interests were not consistent between the righteous army commander who created the righteous army during the Japanese Invasion of Korea in 1592, but there was a factor that made them combine.

First, most of the righteous army chiefs were former civil servants among the aristocrats, but most of them were former officials. The spirit of Geunwang spread among local Confucian scholars in order to practice Confucian Taoism, which was usually learned as a local giant, and they were enraged by the incompetence and cowardice of the local leader and armed men.

Second, the creativity of the righteous army was for the defense of the local people and their relatives, and furthermore, it was the manifestation of national sentiment for Japan's barbarity. Joseon, which regarded Confucian ethics as a thorough social norm, considered the Japanese as aggressors because of the continuous looting of Japanese pirates from the end of Goryeo, and culturally despised them and called them Wae or Seom Orang-ke. When invaded by Japan, it was the creativity of the righteous army that occurred as a national resistance movement.

During the Japanese Invasion of Korea in 1592, the righteous army chiefs were at the top of society in the provinces and served as spiritual leaders, and economically, they were small and medium-sized landowners and had an organic connection with farmers through land. The Japanese invasion of the country destroyed their social and economic foundations.

On the other hand, the people wanted a well-known and reliable righteous army commander to fight under the command of an incompetent general who was forced to serve by the government. In addition, it was advantageous to go to the righteous army rather than the government army to protect parents and wives and children around the local area. Since the royal court also recognized the righteous army as a public army to urge the creativity of the righteous army, the number of participants in the righteous army of the general public continued.

In Gyeongsang province

  • Hapcheon (June 6, 1592): and Chŏng Inhong against Mōri Terumoto
  • Chogye (June 7, 1592): Son Ingap against Mōri Terumoto
  • Ucheokhyeon (July 10, 1592): Kim Myŏn and Kim Sŏngil against Kobayakawa Takakage
  • Yeongcheon (July 27, 1592): Kwŏn Ŭngsu and Pak Chin Fukushima Masanori
  • Uiryeong: Kwak Chaeu against Kobayakawa Takakage
  • Hyeonpung: Kwak Chaeu against Hashiba Hidekatsu
  • Yeongsan: Kwak Chaeu against Hashiba Hidekatsu

In Jeolla province

  • Damyang (June 25, 1592) : Ko Kyŏngmyŏng and Yang Taepak
  • Naju : Kim Ch'ŏnil
  • Gwangju : Kim Tŏngnyŏng

In Chungcheong province

  • Geumsan (July 9, 1592) : Ko Kyŏngmyŏng and against Kobayakawa Takakage
  • Okcheon : Cho Hŏn
  • Geumsan : Yeonggyu and Cho Hŏn
  • Cheongju : Yeonggyu and Cho Hŏn

In Gangwon province

In Hwanghae province

  • Yeonan : Yi Chŏngam

In Pyeongan province

  • Mountain Myohyang : Seosan

In Hamgyeong province

  • Gilju : Chŏng Munbu

Manchu invasion of Korea

During the Jeongmyo-Horan and Byeongja-Horan, righteous army rose up in each region. At this time, the motivation for the righteous army to occur was to overcome the difficulty that was difficult to solve due to the defeat of the government army. In other words, most of them were Geunwangbyeong (근왕병: Royal Provincial Army).

During the Horan period, the righteous army rose early not only in the invaded area but also in the rear area. The righteous army activity in the invaded area was to directly fight the enemy and cause losses. The creativity in the rear area was to gather the recruited righteous army in one place and go to the battlefield to overcome the helplessness of the government army.

However, overall, the activities of the righteous army during the Horan were incomparably weaker than those of the righteous army during the Imjin War. The reason was that after the Imjin War, political turmoil, economic collapse, and social unrest continued, resulting in no sense of unity between the authorities and the people centered on the dynasty.

In fact, during the invasion, the righteous army did not see much clear activity in the area where the enemy invaded. Mock activities were carried out in the rear areas of Honam and Yeongnam, but they were disbanded when Injo gave in to the Qing dynasty while heading to the northern battlefield.

For example, In Yean-hyeon, the seonbi clans of Yean-hyeon, centered on the Gwangsan Kim clan, were active in Hyanggyo. When the Jeongmyo-Horan broke out, the seonbi clans of Yean-hyeon organized and divided the righteous army around the righteous army office (兵廳廳소) by mission, and most of them focused on mobilizing the supplies rather than mobilizing the military. Therefore, the righteous army was disbanded as reinforcement was promoted with little actual military activities. The Righteous Army that rose up in this year is called the Jeongmi Righteous Army (乙巳義兵), initially led by Confucian scholars including Choe Ik-hyeon. However, when government troops suppressed them, Confucian scholars, driven by feudal ethics that prohibited drawing a sword against the king, surrendered voluntarily. Instead, unknown gentry members and local peasants became the core of the righteous armies.

After the disbandment of the Korean Empire's army due to the Japan–Korea Treaty of 1907, a significant number of soldiers joined the Righteous Army. The Righteous Army that rose up in this year is called the Jeongmi Righteous Army (丁未義兵), of which the leaders were either fallen nobles such as Sim Nam-il and Ahn Gyu-hong, or commoners such as Shin Dol-seok.

At the time, the most active area for the Righteous Army struggle was South Jeolla Province, and Japanese landowners in this region became the primary targets of the Righteous Army's activities. In 1909, at the strong request of the Mokpo Japanese Chamber of Commerce, the Japanese Empire launched the so-called Great Suppression of the Southern Insurgents Operation (南韓討伐大作戦), engaging in a decisive battle with the Righteous Army in Korea. As a result, the Righteous Army suffered a decisive blow and was forced to relocate its base to Manchuria and other places. These Righteous Army members grew into the core of the Korean Independence Army.