The Pukkwan campaign () was a series of military engagement between Joseon and Japanese forces in Hamgyong Province from the 16th day, 9th month of 1592 to 28th day, 1st month of 1593. During this campaign, the "Righteous army," a civilian militia led by Chà Âng Munbu, executed local collaborators and successfully repelled the Japanese invasion.
In the wake of the Japanese capture of Hanyang on 3rd day, 5th month of 1592, the invasion of Korea intensified under the strategic leadership of Konishi Yukinaga and Katà  Kiyomasa. While Konishi advanced into Pyongan Province, Katà  spearheaded operations in the northeastern region, swiftly penetrating Hamgyong Province.
At the time, residents of Hamgyong faced systemic discrimination by the central Joseon government, leading to widespread resentment. The discontent intensified when Prince Imhae and Sunhwa, dispatched to recruit royal soldiers, engaged in lootin and exploitation of local resources such as clothes, foods, and other necessities. The civilians in Hamgyeong at times surrendered to the Japanese and either killed or captured officials of the Joseon government, subsequently handing them over to the Japanese army.
When Katà Â's forces advanced to Hoeryong, Kuk Kyà Ângin, based in Hoeryeong, initiated a revolt and defected to the Japanese side, along with Chà Âng Malsu of Myongchon and Kuk Sep'il of Kyongsong. On 23rd day, 7th month of 1592, Kuk Kyà Ângin handed over to Katà Â's forces the two royal princes who had sought refuge in Hoeryong, along with their servants and family members. In return, Katà  granted Kuk Kyà Ângin the authority to govern Hoeryong and conferred control over Kyongsong upon Kuk Sep'il. Following these appointments, Katà  withdrew his main force and established a military presence in Anbyon.
Seeking to consolidate direct control over the region southern corridor of Kilju, Katà  stationed eight commandersâÂÂamong them Katà  Umanojà  and Katà  SeibeiâÂÂin Kilju. He further deployed troops across critical locations along the route from Kilju to Anbyon, thereby reinforcing Japanese strategic dominance in the region.
Civil unrest intensified as Japanese forces expanded their exploitation of local residents and abuse of official authority. Recognizing the shifting tide of public sentiment, local figures Yi Pungsu, Chi Tarwà Ân, Ch'oe Paech'à Ân, and Kang Munu resolved to form a Righteous Army. They extended an invitation to Chà Âng Munbu, who had been in hiding, urging him to assume command of the army. Chà Âng accepted their request and proceeded to organize a militia. In response, several hundred local soldiers and strongmen rallied to his cause.
On 16th day, 9th month of 1592, the righteous army led by Chà Âng Munbu successfully captured and secured Kyongsong, where Kuk Sep'il had been stationed. Following the occupation, Chà Âng issued a proclamation urging the populace to join the resistance. In response, individuals such as Chà Âng Hyà Âllyong, O à ¬ngt'ae, and numerous other soldiers enlisted in the growing force. Alarmed by the fall of Kyà Ângsà Âng, Katà  Umanojà  dispatched a detachment of 100 scouts to assess the situation. However, the reconnaissance unit was promptly repelled by Kang Munu and his cavalry.
Prior to the planned recapture of Kilju, Chà Âng Munbu, responding to the requests of his subordinates, resolved to execute collaborators who had defected to the Japanese. He issued a public notice announcing the formation of the Righteous Army and declaring the intent to punish key rebels, including Kuk Kyà Ângin and Chà Âng Malsu.
In Hoeryà Âng, during 10th month of 1592, a Confucian student, O Yunjà Âk, upon reading Chà Âng Munbu's proclamation, devised a plot to assassinate Kuk Kyà Ângin. Anticipating the attempt, Kuk had O apprehended by his subordinates under cover of night. Although Kuk planned to execute O the following day, another Confucian student, Sin Sejun, mobilized a group of armed men, surrounded Kuk's residence, set it ablaze, and killed him in the ensuing attack.
Meanwhile, in Myà Ângch'à Ân, local peasants rose in revolt against Chà Âng Malsu, though their uprising was suppressed by rebel forces. In response, Chà Âng Munbu dispatched Ku Hwang and Kang Munu to the region. They crushed the rebels and killed Chà Âng Malsu. Subsequently, upon retaking Kyongsong, Munbu ordered the execution of Kuk Sep'il and the remaining collaborators. With these actions, the rebellion in Hamgyong Province was decisively quelled.
Chà Âng Munbu organized his forces into three divisionsâÂÂthe central corps, the left wing, and the right wingâÂÂplacing them under the respective command of Chà Âng Hyà Âllyong, Han Inje, and Yu Kyà Ângch'à Ân. In addition, he deployed smaller ambush units under O à ¬ngt'ae and Wà Ân Ch'ungsà Â, strategically positioning them in concealed locations to carry out surprise attacks.
On 30th day, 10th month of 1592, Wà Ân Ch'ungsà  ambushed a Japanese detachment returning from a raid on a town in Myà Ângch'à Ân, where they had massacred the local population. The ambush forced the Japanese to retreat toward mountain Changdà Âksan, located approximately two kilometers east of Kilju Fortress. The righteous army secured the summit before the Japanese could reach it and launched a concentrated offensive. The Japanese forces withdrew into a nearby valley, only to be surrounded from all sides. That night, heavy snowfall began, and the Japanese troops, unable to withstand the freezing conditions, became militarily incapacitated.
The Japanese forces in Kilju sealed the fortress and reinforced their defensive positions. Joseon troops encircled the stronghold, cutting off access to firewood and other essential supplies. In 11th month of 1592, Chà Âng Hyà Âllyong, Yu Kyà Ângch'à Ân, and O à ¬ngt'ae, led an estimated 3,000 troops in a direct assault on the fortress. However, the siege failed to breach the Japanese defenses due to their determined resistance.
In response, Chà Âng Munbu adopted a strategy of operational isolation, aiming to sever Japanese lines of communication by targeting Ch'aeksà ÂngâÂÂa key junction connecting Tanchon and Kilju. During this maneuver, Joseon forces encountered a Japanese unit engaged in looting a village in Immyong and engaged them in battle at Ssangp'o. The engagement culminated in a Joseon victory on 19th day, 11th month of 1592.
In Tanch'à Ân, a force of 900 soldiers under the command of Katà  Yozaemon was stationed. Kang Ch'an, the magistrate of Tanch'à Ân, sought military assistance from Chà Âng Munbu. In response, on 22nd day, 1st month of 1593, Chà Âng dispatched approximately 200 troops under the command of four officers, including Ku Hwang, and positioned them in ambush at Mach'à Âllyà Âng. To initiate the engagement, around 20 government troops staged a feigned retreat, successfully luring the Japanese forces into the ambush site. The ensuing surprise attack resulted in the deaths of approximately 170 Japanese soldiers, while the Joseon forces sustained no casualties.
As the tide of war began to shiftâÂÂwith the arrival of Ming reinforcements and the defeat of Konishi's forces at the Siege of PyongyangâÂÂKatà  Kiyomasa sought to avoid isolation in Hamgyong Province by retreating toward Hanyang. However, in an effort to relieve the Japanese garrison besieged in Kilju by the righteous army, he mobilized over 20,000 troops and marched toward Kilju.
In response, Chà Âng Munbu withdrew his forces from Tanchon after Katà  crossed Mach'à Âllyà Âng. On 28th day, 1st month of 1593, Joseon forces intercepted Katà Â's army north of Immyong at Paekt'apkyo, inflicting significant casualties. However, the Joseon forces also suffered considerable losses and subsequently withdrew to Myà Ângch'à Ân to regroup and reorganize. That night, Katà  reached the encircled Japanese detachment and immediately retreated with them to Anbyon.
After rescuing the isolated units, Katà  Kiyomasa regrouped his forces in Hamhung on 20 February and then retreated to Anbyon. By 29th day, 2nd month of 1593, he arrived in Hanyang, where it was confirmed that his army had suffered 8,864 casualties out of a total of 22,000 troops. Following this realization, Katà  initiated a full withdrawal.
In the aftermath of the Japanese retreat, the Righteous Army was disbanded, and command was transferred to Yun T'agyà Ân. Tensions soon arose between Chà Âng Munbu and Yun, as the latter was perceived to have claimed disproportionate credit for the campaign's success. As a result, Chà Âng Munbu's role was officially recognized only for his actions in executing rebel collaborators, rather than for his military leadership in the broader conflict.