Imjin War

Japan and Korea before the war

Both Ming China and Joseon Korea emerged during the 14th century after the fall of the Yuan dynasty, embraced Confucian social ideals, and faced similar threats – Jurchen people, who raided along the northern borders, and the wokou, who pillaged coastal villages and trade ships.^[41][42] Both had competing internal political factions, which would influence decisions made before and during the war.^[43][44]

In 1392, General Yi Sŏnggye led a coup to take power in Korea, and he ruled as Taejo of Joseon.^[45] The new regime received recognition from, and integration into, the tributary system of China.^[46][47] Within this tributary system, China assumed the role of a "big brother", while Korea maintained the highest position among the tributary states.^[48][49] Through this tributary relationship, Joseon and Ming shared a security alliance.^[50]

The system also included countries such as the Ryukyu Kingdom, Lan Xang, Đại Việt, and the Ayutthaya Kingdom,^[51][52] who likewise acted as "younger brother[s]" of China.^[53] In 1404, Ashikaga Yoshimitsu, recognized as "King of Japan" by China, had Japan enter the Chinese tributary system. His successor, Ashikaga Yoshimochi, left it in 1408.^[54] Membership in the tributary system was a prerequisite for any economic exchange with China; by exiting, Japan relinquished its trade relationship with China.^{[55][56][n 2]}

Hideyoshi's preparations

By the last decade of the 16th century, Toyotomi Hideyoshi had unified Japan. He rallied support in Japan as a man of relatively humble origins who owed his position to his military might.^[58] He sought military power to legitimize his rule and decrease his dependence on the imperial family.^[59] It is also suggested that Hideyoshi planned an invasion of China to fulfill the dreams of his late lord, Oda Nobunaga,^[60] and to keep his newly formed state united against a common enemy, mitigating the possible threat of civil disorder or rebellion posed by the large number of now-idle samurai and soldiers, and by ambitious daimyos who might have sought to usurp him.^[61]

As early as 1578, Hideyoshi, then fighting under Oda Nobunaga against Mōri Terumoto for control of the Chūgoku region, informed Terumoto of Nobunaga's plan to invade China.^[62] In 1585, Hideyoshi told the Portuguese Jesuit Father Gaspar Coelho of his wish to conquer all of East Asia. Hideyoshi asked Coelho to send a message to King Philip II of Spain, who was also King Philip I of Portugal, asking that he make his navy available to help Japan. However, Philip refused Hideyoshi, preferring not to upset China.^[63] Japan's legal tribute missions to China, and hence their right to trade with China, had ceased by the mid-16th century and was replaced by Sino-Japanese smuggler-pirates known as the wokou.^[63] Hideyoshi spoke not only of his desire to "slash his way" into Korea to invade China, but also the Philippines, and India.^[63]

Japan may have begun the construction of as many as 2,000 ships for an attack as early as 1586.^[64] To estimate the strength of the Korean military, Hideyoshi sent an assault force of 26 ships to the southern coast of Korea in 1587.^[65] On the diplomatic front, Hideyoshi helped to police trade routes against the wokou.^[66] Beginning in March 1591, the Kyushu daimyos and their labor forces constructed Nagoya Castle in modern-day Karatsu, Saga, as the center for the mobilization of the invasion forces.^[67]

Land forces

Japan

The samurai were at the core of the Japanese military.^[90] The standard samurai weapon by 1592 was the yari, a spear meant to stab, often with a cross-blade that allowed a samurai to pull his opponent from his horse.^[90] If a samurai wished to cut his opponent rather than stab, the weapons were the ōdachi, an extremely long sword with a huge handle, or the naginata, a polearm with very sharp curved blade.^[90] The most famous of all the samurai weapons was the katana, a sword described by British military historian Stephen Turnbull as "...the finest edged weapon in the history of warfare".^[90] Samurai never carried shields, and in lieu of them, the katana was used to deflect blows.^[90] By 1592, the armor of the samurai was lamellae made from iron or leather scales tied together which had been modified to include solid plate to help protect the samurai from bullets.^[90] Samurai on horseback would often dismount when engaged in action, acting as mounted infantry. While specialized firearms were used on horseback, most cavalrymen preferred the yari,^[91] but its use was limited by the increasing use of firearms by the Koreans and Chinese.^[70] Samurai engaged in psychological warfare by wearing iron masks into battle with a mustache made of horsehair and a "sinister grin" illustrated.^[92]

Most of the Japanese troops in Korea were ashigaru light infantry, usually conscripted peasants armed with either yari, tanegashima or bows called yumi.^[92] Unlike the samurai, ashigaru wore cheap suits of iron armour around their chests.^[92] Japanese arquebusiers fought in the European style. Men trained to fire their guns in formation to create a volley of fire, then to go down on their knees to reload, while the men behind them fired, and the cycle repeated.^[92]

Hideyoshi mobilized his army at Nagoya Castle, newly built for the sole purpose of housing the invasion forces and the reserves. None of the original structures remain, but the castle's ruined foundations survive in the formerly separate town of Chinzei, now part of the city of Karatsu in Saga Prefecture. 158,800 soldiers, laborers, and transport troops spread across nine divisions were prepared to take part in the invasion.^[93] Roughly a third of the force consisted of armed fighting units, while the remaining two thirds filled supporting roles. Another two divisions, with 21,500 between them, were held in reserve on Tsushima Island and Iki Island.^[94] The Japanese used a total of 320,000 troops throughout the war.^[95]

One daimyo whose military service quota has been preserved in a written record is Shimazu Yoshihiro, whose contribution consisted of:^[96]

• 600 samurai
• 300 flag bearers
• 1,500 arquebusier ashigaru
• 1,500 archer ashigaru
• 300 spearmen ashigaru
• 6,400 laborers and boatmen

Firearms

Since its introduction by Portuguese traders on the island of Tanegashima in 1543, the arquebus had become widely used in Japan.^[111] From the 1560s, tanegashima guns were produced on a scale of at least several thousand a year.^[112] By the late sixteenth century, Japan may have had more muskets than any other nation in the world, though bows were still used alongside them.^[113][114] In contrast, though both Korea and China had also been introduced to firearms similar to the Portuguese arquebus, most were older models. Korean soldiers would sometimes use hand cannons with a simple mechanism and either a gunstock or wooden shaft attached.^{[citation needed]}

While tanegashima were superior to Korean bows in terms of penetration and range, they had a lower rate of fire.^[115] Accounts from the Annals of Joseon, essays, and diaries of Korean officials express that muskets alone could not ensure victory. Charges of Japanese troops with spears and swords were often more decisive than musketry. The Koreans were poorly trained in close combat, and lacked battlefield experience and discipline. The following words from a Korean military official named Yi Siŏn [ko] to the Korean king discusses this weakness:

The King asked him [Yi Siŏn], "You have already told me about the low accuracy of Japanese muskets. Why, then, are Korean armies having great problem with defeating them?"

[Yi Siŏn] then answered, "The Korean soldiers cower before the enemy and flee for their lives even before they have engaged the enemy. As for the commanders, they seldom leave their positions because they fear that they might be executed for deserting. However, there is a limit to executing deserting soldiers since there are so many of them. Truly, the Japanese aren't good musketeers, but they advance so rapidly that they appear right in front of the Koreans in the time Koreans can shoot only two arrows. It is said that Koreans are good archers, but they seldom hit the targets when the enemy is too far away, and are too scared to shoot when the enemy is near because they fear Japanese swords. Archery often becomes useless because Koreans, fearing the Japanese arme blanche, can barely shoot. The Japanese are reputed to be good swordsmen, but it is possible for Koreans to draw swords and hold their ground. However, the Koreans seldom do this and merely run for their lives."^[116]

However, another Korean official, Yu Sŏngnyong, claims that the Japanese arquebusiers had undeniable superiority over long distances, which (along with low discipline and combat experience of the Korean army) was the main cause of defeats:

In the 1592 invasion, everything was swept away. Within a fortnight or a month the cities and fortresses were lost, and everything in the eight directions had crumbled. Although it was [partly] due to there having been a century of peace and the people not being familiar with warfare that this happened, it was really because the Japanese had the use of muskets that could reach beyond several hundred paces, that always pierced what they struck, that came like the wind and the hail, and with which bows and arrows could not compare.^[117]

Today, the Japanese exclusively use muskets to attack fortifications. They can reach [the target] from several hundred paces away. Our country's bows and arrows cannot reach them. At any flat spot outside the walls, the Japanese will build earthen mounds and "flying towers." They look down into the fortifications and fire their bullets so that the people inside the fortifications cannot conceal themselves. In the end the fortifications are taken. One cannot blame [the defenders] for their situation.^[118]

The Japanese also saw arquebuses as crucial. A Japanese commander wrote home in 1592:

Please arrange to send us guns and ammunition. There is absolutely no use for spears. It is vital that you arrange somehow to obtain a number of guns. Furthermore, you should certainly see to it that those person departing [for Korea] understand this situation. The arrangements for guns should receive your closest attention.^[119]

The Japanese commander Asano Yoshinaga wrote home to his father:

When the troops come [to Korea] from the province of Kai, have them bring as many guns as possible, for no other equipment is needed. Give strict orders that all men, even the samurai, carry guns.^[120]

Artillery

Further information: Korean cannon

Korean mainly used artillery in siege action and for defending castles.^[121] In a few instances, some irregular Korean units with government-supplied weapons fired explosive shells from mortars.^[121] The Koreans also made use of hwacha, two-wheeled carts carrying hole-filled boards fitted to carry either 100 steel-tipped rockets or 200 singijeon (rocket arrows) to be fired all at once. They were especially effective against dense formations of troops.^[122]

According to Turnbull, Chinese field artillery and siege cannon were the finest in the region.^[110] Chinese artillery was made from cast iron, and were divided into several types, the most important being the "great general cannon", large breech-loading cannon atop two-wheeled carts, shooting iron balls weighing about 10 kilograms, and the folang zhi (佛朗支), which was also breech-loading.^[110] The Chinese also employed the hu dun pao bombard, which was noted for being decisive in retaking Pyongyang.^[123]

The Japanese employed field artillery only where strategically advantageous in both siege and field warfare situations, often using captured pieces where available.^{[citation needed]}

Naval forces

Compared to Japanese ships, Korean ones were faster, more maneuverable, more heavily built, with thick wooden hulls impervious to musket fire, and were equipped with large cannons.^[124] The standard Korean ship was the panokseon, similar in appearance to standard Japanese warships, but larger and with heavy cannons; most Japanese ships had no cannons at all at the start of the war.^[125] The famous heavily armored and armed "turtle ships" were a minority of the Korean navy's ships.^[125] Korean and Japanese accounts both talk much of the "turtle ships", but no such ship has survived, and historians still debate about what turtle ships looked like, though most now agree that they were, in fact, turtle-shaped.^[125]

The centralized structure of the Korean navy was also a factor in its successes. With Hideyoshi unable to directly command the Japanese naval effort, each daimyo was left to himself to work out how best to face the Korean threat, according to his own interests. Personal motivations greatly hindered the Japanese in facing the unified fleet of Yi Sun-sin, eventually made supreme commander of the whole Korean navy, a role the Japanese had no counterpart to.^[124]

The Japanese, who almost totally lacked naval artillery as they relied on anti-personnel naval techniques such as naval boarding and small arms fire,^[124][84] could be outranged and bombarded with impunity by Korean ships outside the range of Japanese muskets, arrows, and catapults.^[84] When the Japanese attempted to rerofit cannons to their ships,^[126] their lightweight ship design ^[84][127] precluded the use of more than a few per vessel, and they usually lacked the range or firepower of their Korean counterparts.^[128] In order to bolster their fleet, the Japanese considered employing two Portuguese galleons in the invasion.^{[129][clarification needed]}

Command

Japan

The Japanese army had no central command system with a hierarchy of government-appointed officers; rather, it consisted of armies raised, maintained, and led by daimyos, feudal lords subordinate to the shogun who owned most of the land in Japan. This decentralized structure allowed armies to operate fully independently of one another.^[130] Hideyoshi himself never left Japan, remaining near Kyoto; however, the idea of conquering China was his obsession, and throughout the war, he refused to accept defeat, treating the war as simply a matter of willpower. Turnbull writes: "In a tactical sense, therefore, Hideyoshi cannot be considered as one of the commanders, but, as his will drove the whole project along until he died, his political influence cannot be underestimated".^[131]

The commander of the Japanese First Division and overall commander of the invasion force was Konishi Yukinaga, daimyo of Uto in Higo Province of Kyushu. He was chosen as commander of the invasion force more because of his diplomatic skills than military skills, as Toyotomi Hideyoshi did not expect the Koreans to resist.^[132] Konishi had converted to Catholicism in 1583, and was known to the Spanish and Portuguese as Dom Agostinho.^[133] Katō Kiyomasa, who led the Second Division into Korea, was known in Japan as Toranosuke ("the young tiger") and to the Koreans as the "devil general", on account of his ferocity.^[133] Katō was a devoted follower of Nichiren Buddhism, a type of Buddhism closely associated with militarism and ultra-nationalism in Japan, and his relations with the Catholic Konishi were extremely unfriendly, to the extent that the two men almost never met during the campaign in Korea.^[134] Katō's battle standard was a white pennant which carried a message alleged to have been written by Nichiren himself reading Namu Myōhō Renge Kyō ("Hail to the Lotus of the Divine Law").^[134] Wakisaka Yasuharu was one of Hideyoshi's leading naval commanders who had been named daimyo of the island of Awaji in the Seto Inland Sea in 1585, where he learned much about seafaring as the island is located close to whirlpools which are notoriously dangerous for sailors.^[134]

Joseon

Officers in the Joseon Army and Navy also came exclusively from the aristocracy, but unlike the militarist Japanese aristocrats trained from their youth, for the Joseon aristocracy, scholarship was valued and war was disparaged as something unworthy of a Confucian gentleman-scholar.^[135] The quality of Korean generalship was quite variable; some Korean officers were able and others were men who had not devoted much time to the study of war.^[108] One standout was admiral Yi Sun-sin. He began the war as a provincial naval commander associated with Jeolla Province,^{[n 4]} and later became the commander of the Korean navy. He was described by Turnbull as "Korea's greatest hero" and "one of the outstanding naval commanders in the entire history of the world".^[134]

Initial attacks

Landing of the First Division

Main articles: Siege of Busan, Battle of Dadaejin, and Siege of Dongnae

On 23 May 1592, 7,000 Japanese soldiers of the First Division, led by Konishi Yukinaga,^[141] departed from Tsushima Island in the morning, arriving outside the Korean port city of Busan in the evening.^[142] Korean naval intelligence had detected the Japanese fleet, but Wŏn Kyun, the Right Naval Commander of Gyeongsang Province, misidentified the fleet as trading vessels on a mission.^[143] A later report of the arrival of an additional 100 Japanese vessels raised his suspicions, but he did nothing about it.^[143] Sō Yoshitoshi landed alone on the Busan shore to ask the Koreans for safe passage to China. The Koreans refused, and Sō Yoshitoshi laid siege to the city. Konishi Yukinaga attacked the nearby fort of Dadaejin the next morning.^[142] Japanese accounts claim that the battles resulted in the annihilation of Korean forces, while a Korean account claims that the Japanese themselves took significant losses before sacking the city of Busan.^[144] Chŏng Pal, the Korean commander at Busan, was killed, and with his death, Korean morale collapsed.^[145] In the meantime, Konishi took the fort of Dadaejin.^[146] Konishi ordered that no prisoners be taken, and the entire garrison was massacred.^[146] Konishi and the First Division then turned north, marching to take Hanseong.^[146]

First Division attack

On the morning of 25 May 1592, the Japanese First Division arrived at the Dongnae Fortress.^[144] Konishi sent a message to Song Sang-hyeon, the commander of the fortress, explaining to him that his objective was the conquest of China and if the Koreans would just submit, their lives would be spared. Song replied, "It is easy for me to die, but difficult to let you pass", which led Konishi to order that no prisoners be taken to punish Song for his defiance.^[146] The resulting siege of Dongnae lasted twelve hours, killed 3,000, and resulted in a Japanese victory.^[147] The Japanese took no prisoners and killed everyone at Dongnae, including civilians and even cats and dogs.^[146] Konishi's sought to terrify the Koreans, but he instead stimulated Korean resistance, as ordinary Koreans were enraged.^[146]

After taking Dongnae, Konishi took the castle of Miryang, which he followed up by taking Daegu, which surrendered without opposition.^[148] After crossing the Nakdong River, Konishi learned that the Koreans were concentrating their troops at Sangju.^[148] In the meantime, Korean envoys had been sent to the China to ask the Wanli Emperor to protect his tributaries in Korea by sending an army to drive out the Japanese.^[148] The Chinese assured the Koreans that an army would be sent, but they were engaged in a major war in Ningxia, and the Koreans would have to wait for the arrival of their assistance.^[148]

Capture of Hanseong

The Second Division, led by Katō Kiyomasa, arrived at Chungju, with the Third Division camped not far behind.^[157] There, Katō expressed his anger against Konishi Yukinaga for not waiting at Busan as planned, and attempting to take all of the glory; Nabeshima Naoshige proposed a compromise of dividing the Japanese troops into two groups to follow different routes to Hanseong, and allowing Katō Kiyomasa to choose the route that the Second Division would take to reach Hanseong.^[157] The division of the Japanese forces was mainly due to the rivalry between Katō and Konishi, but there was a certain "strategic merit" in dividing their forces in that Katō's advance would protect the Japanese from any attempt by the Jurchen leader Nurhaci to attack their flank.^[148] However, the division of the Japanese forces also meant that Konishi would have to take on the Chinese alone when their army arrived.^[148]

The two divisions raced to capture Hanseong from 8 June; Katō took the shorter route across the Han River while Konishi went further upstream for calmer waters.^[157] Konishi arrived at Hanseong first, on 10 June, while the Second Division was halted at the river with no boats with which to cross.^[157] The First Division found the castle undefended with its gates locked, as King Seonjo had fled the day before.^[158] The Japanese broke into a floodgate, located in the castle wall, and opened the city's gate from within.^[158] Katō's Second Division arrived at the capital the next day after taking the same route as the First Division, and the Third and Fourth Divisions arrived the day after.^[158] Meanwhile, the Fifth, Sixth, Seventh, and Eighth Divisions had landed on Busan, with the Ninth Division kept in reserve on the island of Iki.^[158]

Parts of Hanseong had already been looted and torched, including bureaus holding slave records and weapons, and they were already abandoned.^[158] Korean general Kim Myŏngwŏn, in charge of the defenses along the Han River, had retreated.^[159] The king's subjects stole the animals in the royal stables and fled before him, leaving their king to rely on farm animals.^[159] In every village, the king's party was met by inhabitants, lined up by the road, grieving that their king was abandoning them, and neglecting their duty of paying homage.^[159] Parts of the southern shore of the Imjin River were burnt to deprive the Japanese troops of materials with which to make their crossing, and General Kim Myŏngwŏn deployed 12,000 troops along the river.^[159]

Japanese campaigns in the north

Naval campaigns of 1592

After securing Pyongyang, the Japanese planned to cross the Yalu River into Jurchen territory and use the waters west of the Korean peninsula to supply the invasion.^[180] However, Yi Sun-sin, who, a provincial-level naval commander, destroyed the Japanese ships transporting troops and supplies.^[180] Japan, lacking enough arms and troops to carry on the invasion of China, changed the objective of the war to the occupation of Korea.^[180]

When the Japanese landed at Busan, Pak Hong, another provincial-level naval commander, destroyed his entire fleet, his base of operations, and all armaments and provisions, then fled.^[143] Provincial-level naval commander Wŏn Kyun, acted similarly, and fled to Konyang with only four ships.^[143] As a result, there was no Korean naval activity around Gyeongsang Province.^[143] The surviving two fleets were active only on the western side of Korea.^[143] Wŏn Kyun later sent a message to Yi Sun-sin that he had fled to Konyang after being overwhelmed by the Japanese in a fight.^[181] However, Yi Sun-sin's battles steadily affected the war and put significant strain on the sea lanes along the western Korean Peninsula that supported the Japanese advance.^[182]

The Korean navy relied on a network of local fishermen and scouting boats to receive intelligence of the enemy movements.^[182] On the dawn of 21 July 1592, Yi Sun-sin and Yi Ŏkki set sail with 24 panokseon, 15 small warships, and 46 fishing boats, and arrived at Gyeongsang Province.^[182] The Japanese had been sailing up and down the Korean coast, looting and burning seaside villages, and did not expect opposition from the Korean navy.^[183]

A combined Korean flotilla of 91 ships including elements associated with Wŏn Kyun and Yi Sun-sin began circumnavigating Geojedo, bound for Gadeokdo from 23 July, but scouting vessels detected 50 Japanese vessels at Okpo.^[187][182] Upon sighting the approaching Korean fleet, some of the Japanese who had been busying themselves with plundering got back to their ships, and began to flee.^[182] The Korean fleet encircled the Japanese ships and finished them with artillery bombardments.^[188] The Japanese fired with their arrows and arquebuses, but the Koreans kept a good distance from them, rendering the Japanese fire ineffective.^[183]

The Koreans spotted five more Japanese vessels that night, and destroyed four.^[188] After one day's fighting, Yi Sun-sin's fleet had destroyed 26 Japanese ships.^[189] The next day, the Koreans approached 13 Japanese ships at Jeokjinpo.^[188] In the same manner as the previous success at Okpo, the Korean fleet destroyed 11 Japanese ships—completing the Battle of Okpo without the loss of a single ship.^[188] The Japanese generals were shocked to hear of the Battle of Okpo, as it threatened to cut them off from Japan.^[189] After his victory, Yi Sun-sin found the burnt remains of countless coastal villages, where the Japanese had enslaved the women and killed the men.^[189]

About three weeks after the Battle of Okpo, Yi Sun-sin and Wŏn Kyun sailed with 26 ships toward the Bay of Sacheon after receiving an intelligence report of Japanese presence there.^[190][191] Yi Sun-sin had left behind his fishing vessels that made up most of his fleet in favor of his newly completed turtle ship.^[190] At Sacheon, the Japanese ships were anchored in the bay below a promontory where the Japanese had set up a command base.^[189]

On 8 July 1592, the fleet arrived at the bay of Sacheon, where the outgoing tide prevented the Korean fleet from entering.^[190] Therefore, Yi Sun-sin ordered the fleet to feign withdrawal, which the Japanese commander, Wakisaka Yasuharu, observed.^[192] The Japanese gave chase, embarked their 12 ships, and pursued the Koreans.^[190] The Korean navy counterattacked, with the turtle ship in the front, and successfully destroyed all 12 ships in the Battle of Sacheon.^[190][193] The superior firepower and armor of the turtle ships proved effective.^[193] Admiral Yi was badly wounded when he was shot in the shoulder by a Japanese sniper.^[193]

At the Battle of Dangpo, 21 Japanese ships commanded by Kurushima Michiyuki were in the process of sacking a Korean seaside village, when the Korean fleet appeared to offer a challenge.^[194] Yi Sun-sin once again feigned retreat to elicit Japanese pursuit, and then ambushed the Japanese on the open sea and killed Kurushima.^[195]

Yi Sun-sin spent the next days searching for Japanese ships, which he found at Danghangpo.^[195] Yi formed his ships in a circle while a turtle ship rammed the Japanese flagship, resulting in a melee battle.^[196] Yi wanted to annihilate the Japanese, and fearing that the Japanese might land their ships in order to escape, feigned retreat to bring the battle out to the open sea.^[196] The feigned retreat worked, and the Japanese followed the Koreans to the open sea. Yi then surrounded the Japanese ships from both flanks, resulting in all but one of the Japanese ships being taken or sunk.^[196] Yi Sun-sin sent King Seonjo the salted heads of 43 samurai officers.^[196] The next day, the one Japanese ship that had escaped was confronted by a Korean ship sent to capture it, leading to a fight when the Koreans boarded the Japanese ship.^[196] All 88 sailors of the Japanese ship were killed, and Yi had their ears cut off to be "salted and packed in a box for shipment to the court".^[197]

Battle of Hansan Island

Main article: Battle of Hansan Island

In response to the Korean navy's success, Toyotomi Hideyoshi recalled three commanders from land-based activities: Wakisaka Yasuharu, Katō Yoshiaki, and Kuki Yoshitaka.^[198] Hideyoshi understood that if the Koreans won command of the sea, it would mean the end of the invasion, and ordered the destruction of the Korean fleet and for Yi Sun-sin's head to be brought to him.^[197] However, the commanders arrived in Busan nine days before Hideyoshi's order was actually issued, and assembled a squadron to counter the Korean navy.^[198] Eventually, Wakisaka completed his preparations, and his eagerness to win military honor pushed him to launch an attack against the Koreans without waiting for the other commanders.^[199]

Following this, the combined Korean navy of 53 ships,^[200] under the commands of Yi Sun-sin and Yi Ŏkki, carried out a search-and-destroy operation because the Japanese troops on land were advancing into Jeolla Province.^[201] Jeolla Province was the only Korean territory to be untouched by major military action, and served as home for the three commanders and the only active Korean naval force.^[201] The Korean navy considered it best to destroy naval support for the Japanese to reduce the effectiveness of the enemy ground troops.^[201]

On 13 August 1592, the Korean fleet, sailing from Miruk Island, received intelligence that a large Japanese fleet was nearby.^[201] The Korean fleet anchored off Dangpo, where they learned that the Japanese fleet had just entered the narrow strait of Gyeonnaeryang that divided Koje Island.^[201][202] The following morning, the Korean fleet spotted the Japanese fleet of 82 vessels anchored in the straits of Gyeonnaeryang.^[201] Due to the narrowness of the strait and the hazard posed by the underwater rocks, Yi Sun-sin sent six ships as bait to lure out 63 Japanese vessels.^[200] The Japanese fleet pursued and, once in open water, was surrounded by the Koreans.^[203] At least three turtle ships spearheaded the fight against the Japanese, and the Korean vessels fired cannon volleys into the Japanese.^[203] The Korean ships then engaged in a free-for-all battle with the Japanese, maintaining enough distance to prevent the Japanese from boarding; Yi Sun-sin permitted melee combats only against severely damaged Japanese ships.^[203] During the battle, the Korean navy made use of a metal-cased fire bomb that caused substantial damage to Japanese deck crews, and caused fierce fires on board their ships.^[204][205]

The battle ended in a Korean victory, with Japanese losses of 59 ships—47 destroyed and 12 captured.^[206] Not a single Korean ship was lost during the battle. Several Korean prisoners of war were rescued by the Korean soldiers throughout the fight. Wakisaka Yasuharu escaped due to the speed of his flagship.^[206] When the news of the defeat at the Battle of Hansan Island reached Toyotomi Hideyoshi, he ordered the Japanese invasion forces to cease all further naval operations.^[207]

Korean militias

From the beginning of the war, Koreans organized militias that they called "righteous armies" to resist the Japanese invasion.^[218] These militias were raised throughout the country and participated in battles, guerilla raids, sieges, and the transportation and construction of wartime necessities.^[219]

There were three main types of Korean "righteous army" militias during the war: the surviving and leaderless Korean regular soldiers, yangbans and commoners, and Buddhist monks.^[219] By the summer of 1592, there were about 22,200 Korean guerrillas serving the Righteous Army, who tied up much of the Japanese force.^[220]

During the first invasion, Jeolla Province remained the only untouched area on the Korean peninsula.^[219] In addition to the successful patrols of the sea by Yi Sun-sin, the activities of volunteer forces pressured the Japanese troops to avoid the province in favour of other priorities.^[219]

Siege of Jinju

Jinju was a strategic stronghold that defended Gyeongsang Province. The Japanese knew that control of Jinju would mean access to the ricebelts of Jeolla Province. Accordingly, an army under Hosokawa Tadaoki approached Jinju. Jinju was defended by Kim Simin, commanding a Korean garrison of 3,000 men.^[229] Kim had recently acquired about 170 new arquebuses.^[229] Kim 's men dropped heavy stones and bombs while firing their arquebuses, and they stopped the Japanase assault.^[229]

Hosokawa ordered a new assault with the samurai advancing this time under bamboo shields with covering fire from their arquebuses, which allowed them to place ladders across the walls of Jinju.^[230] A scene of carnage occurred, with the Koreans dumping rocks and delayed action bombs down on the Japanese.^[230]

For three days, the Japanese attacked Jinju with the moats becoming full of their dead.^[231] On 11 November 1592, a force of Korean guerrillas led by Kwak Chaeu arrived as the relief force, and to fool the Japanese into thinking his force was much larger than it was, Kwak ordered his men to light fires at night on the hills while blowing their conch shells.^[231] On 12 November, Hosokawa Tadaoki ordered a final attempt to storm Jinju, with heavy fighting on the northern gates, with General Kim being killed when a Japanese bullet went through his head, but the Korean arquebus fire drove off the Japanese.^[232] At that time, another Korean relief force bringing badly needed ammunition arrived up the Nam River, causing Hosokawa to break off the siege, who argued that with the Japanese deep in enemy territory and no reserves to cover his rear that it was too dangerous to continue the siege.^[231] Toyotomi Hideyoshi was enraged when he heard of the defeat, saying the Japanese should never be defeated by Koreans, and vowed vengeance.^[231] With the help of arquebuses, cannon, and mortars, the Koreans were able to drive the Japanese from Jeolla Province. The result of the battle at Jinju prevented the Japanese from entering Jeolla Province.

Intervention of Ming China

Unable to repel the invasion, Korea ultimately had to rely on the intervention of Ming China to halt the Japanese advance, despite the various logistical and organizational difficulties suffered by the Japanese.^[233] Korean Court historian and politician Yu Sŏngnyong stated that the Korean naval victory stalled the entire strategy of the invaders, isolating Konishi Yukinaga's army at Pyongyang and securing Chinese waters from the feared Japanese attack, such that "the Celestial Army could come by land to the assistance" of Korea.^[197][233] Viewing the crisis in Joseon, the Wanli Emperor and the Ming court were initially confused as to how their tributary could have been overrun so quickly.^[234]

The Korean court was initially hesitant to call for help from the Ming, and began a withdrawal to Pyongyang.^[234] After repeated requests by King Seonjo, and after the Japanese army had already reached Korea's border with China, China finally came to the aid of Korea.^[29] China was also obligated to assist Korea because Korea was a tributary state of China, and the Ming dynasty did not tolerate the possibility of a Japanese invasion of China.^[235][236] The governor of Liaodong eventually acted upon King Seonjo's request for aid following the capture of Pyongyang by sending a small force of 5,000 soldiers led by Zu Chengxun.^[237] Zu, a general who had fought against the Mongols and the Jurchens, held the Japanese in contempt.^[232] This cavalry force advanced almost unhindered and entered Pyongyang, but was decisively defeated by the Japanese troops in the city. On 23 August 1592, the Chinese attacked under the cover of a heavy rainstorm, taking the Japanese by surprise.^[238] Once the Japanese realized that they outnumbered the Chinese by six to one, they allowed the Chinese cavalry to spread out over the streets of Pyongyang and counter-attacked, using their superior numbers to annihilate the Chinese.^[238] As the Chinese retreated into the muddy fields outside of Pyongyang, the samurai cut them down in the hundreds.^[238] One of their leading generals, Shi Ru, was killed in this engagement. The Japanese were elated at defeating a Chinese army, the foremost power in East Asia, but Konishi Yukinaga grew despondent during the fall of 1592 as it became clear that no reinforcements would arrive from Japan.^[238]

The fleet of Admiral Yi Sun-sin prevented Japanese ships from landing, while the Righteous Army guerrillas left the Japanese forces in northern Korea largely cut off from the forces in southern Korea.^[238] At conference in Hanseong, Konishi told Ukita Hideie that he was not certain if Pyongyang could be held if the Chinese were to attack again with greater numbers.^[238] During the later half of 1592, the Ming sent investigation teams into Pyongyang to clarify the situation.^[234] Following Chinese victory in Ningxia, the Chinese had the forces available to send to Korea. In January 1593, Ming Emperor dispatched a larger force under Song Yingchang and Li Rusong, the general who crushed the Ningxia revolt to Korea.^[238]

According to the collection of letters left by Song Yingchang, the strength of the Ming army was around 40,000,^{[n 6]} composed mostly of garrisons from the north, including around 3,000 men with experience against Japanese pirates under Qi Jiguang. Li wanted a winter campaign as the frozen ground would allow his artillery train to move more easily than it would under the roads turned into mud by the fall rains.^[239] On 5 January 1593, Wu Weizhong led an advance force of 3,000 men across the Yalu River into Korea, followed by two battalions of 2,000 men each later the same day.^[238] At Uiju, King Seonjo and the Korean court formally welcomed Li and the other Chinese generals to Korea, where strategy was discussed.^[240]

Thailand, a longtime faithful tributary state of the Chinese,^[241][242] offered to directly attack Japan to intervene in Toyotomi Hideyoshi's plans, but Ming did not accept, instead ordering it to attack Burma.^[243]

Siege of Pyongyang

On 5 February 1593, the Ming army arrived outside Pyongyang accompanied by a group of Korean soldiers. Ming general Li Rusong was appointed the commander of all armies in Korea. After initial attempts to negotiate with the Japanese defenders broke down, the two sides began skirmishing on the outskirts of the city.^[26] Li Rusong attempted to dislodge a Japanese garrison on the hills north of the city while Konishi Yukinaga attempted a night raid on the Ming camp.^[26] The Japanese night attack was beaten back by the Chinese archers, and Li ordered a feigned retreat, leading the over-confident samurai to fall into a trap, resulting in their annihilation.^[240] The Sino-Korean force consisted of 43,000 Chinese, 10,000 Koreans, Righteous Army guerrillas, and about 5,000 warrior monks.^[244] Li admitted that the Japanese infantry were better equipped with guns, but assured his officers: "Japanese weapons have a range of a few hundred paces, while my great cannon have a range of five to six li [2.4 km]. How can we not be victorious?"^[240] The city of Pyongyang was one of the most powerful fortresses in Korea, and to take it, Li's plans called for surrounding the city on all four sides, starting a bombardment under which his infantry would advance.^[245]

The Korean warrior monks, led by Abbot Hyujeong, attacked the headquarters of Konishi Yuninaga on Moranbong, coming under heavy Japanese arquebus fire, taking hundreds of dead, but they persevered.^[230] Later that same day, the Chinese under Wu Weizhong joined the attack, and with a real danger that Konishi would be cut off from the rest of his army, So Yoshitoshi led a counterattack that rescued the Japanese forces from Moranbong.^[245] After the fall of Moranbong after two days fighting, Li Rusong ordered his cannons to open fire while fire arrows and incendiary bombs set much of the city on fire.^[245] On the morning of 6 February, Li ordered an all-out assault on three sides of the city. The Chinese took heavy losses, but Li, whose horse was killed, was able to bring up the siege ladders.^[246] Li had offered 5,000 ounces of silver for the first man to get over the wall, an honor that was claimed by an infantryman from Zhejiang Province named Luo Shangzhi, who got up unto the wall while using his halberd to great effect.^[246]

Japanese defenders were forced off the walls fairly quickly, and retreated to the citadel they built on the eastern portions of the city. Chinese officers initially scoffed at the earth walls of the Japanese citadel, but after coming under fire from the Japanese arquebuses, soon learned to respect the defense.^[246] The Koreans and Chinese were unwilling to commit to a direct assault on the heavily defended fortification during the day. Instead, they left an opening for the Japanese to rally while making preparations for a fire assault on their position at night. Japanese forces sallied out of the undefended eastern walls and made a run for Hanseong, and they were hit with additional ambushes on the way back south and took heavy casualties.^[26][247]

The fortress of Pungsan, held by Otomo Yoshimune of the Third Division, had been abandoned and burned down by him, before Konishi's force reached it, adding to the misery of the retreat.^[248] Otomo ruined his reputation by retreating without being attacked, and as a result, the Otomo clan, one of the oldest and most respected daimyo families on Kyushu, were disgraced for his apparent cowardice.^[248] Song Yingchang's letters on 1 March 1593, described the battle in full to the Ming court. After their defeat, the Japanese shifted their strategy to hit-and-run tactics and ambushes. The use of gunpowder technology and street fighting contributed to the victory, which would permanently deter the invasion.^[249]

Battle of Byeokjegwan

Soon after retaking Pyongyang, Li Rusong also succeeded in retaking the major city of Kaesong on 19 January 1593,^[26] and met only minor resistance from the Japanese defenders. Overconfident with his recent success and possibly misled by false reports,^[26] Li Rusong advanced towards the capital city of Hanseong with his allied army of 20,000^[250] on 21 January 1593. On 26 January, the force ran into an unexpected confrontation at Byeokjegwan with a large Japanese formation of about 30,000.

Initially, the scouting party of the group under Zha Dashou and a Korean general confronted a small band of Japanese numbering no more than 600 men. The party overran them successfully but soon ran into a much larger host under Tachibana Muneshige, and retreated to a nearby hill to defend themselves. Upon hearing of his scouting party's plight, Li decided to rush forward with the rest of his small host. He met up with his scouting party around noon, but by that time even more Japanese forces were converging on the area.

The Ming forces gradually retreated north while fighting off several waves of attacks. Li Rusong and many other generals personally fought in the brawl, and they sustained heavy casualties before they met up with the rest of their army toward the later portion of the day. At that point, the Japanese gave up further attacks and both sides pulled back. Because the Ming suffered heavy casualties among their elite retinues, Li became reluctant to move aggressively for the remainder of the war.^[26]

Battle of Haengju

The Japanese invasion of Jeolla Province was pushed back by General Kwŏn Yul at the hills of Ichiryeong, where outnumbered Koreans fought Japanese troops in the Battle of Byeokjegwan and gained a victory. Kwŏn Yul quickly advanced northwards, retaking Suwon and then swung north toward the fortress of Haengjusanseong, a wooden stockade on a cliff over the Han River, where he would wait for Chinese reinforcements. After he was informed that the Ming army under Li Rusong was pushed back at Byeokje, Kwŏn Yul fortified Haengju.^[251] Kwon's force of 2,300 men was a mixture of regulars, warrior monks, and Righteous Army guerrillas.^[251]

Bolstered by the victory at Byeokjegwan, Katō Kiyomasa and his army of 30,000 advanced to the south of Hanseong to attack Haengjusanseong, an impressive mountain fortress that overlooked the surrounding area.^[251] An army of a few thousand led by Kwŏn Yul was garrisoned at the fortress, waiting for the Japanese. Katō believed his army would destroy the Koreans and therefore ordered the Japanese soldiers to simply advance upon the steep slopes of Haengju with little planning at about 6 am.^[251] Kwŏn Yul responded to the Japanese advance with fierce fire from the fortification using hwachas, rocks, handguns, and bows.^[251] Kwŏn had trained his men to fire their hwach'as all at once, and as the Japanese were packed closely together, the volley from the "fire wagons" inflicted heavy losses.^[252] The women of Hanseong joined their menfolk, bringing up rocks in their skirts.^[252] In the course of nine assaults, the Japanese pushed the Koreans back to their second line, but could advance no further. Korean sources estimate up to 10,000 Japanese may have been killed or wounded in the process.^{[252][n 7]} Facing unexpected resistance and mounting casualties, Katō Kiyomasa burned his dead and pulled his troops back.

The Battle of Haengju was an important victory for the Koreans, as it greatly improved the morale of the Korean army. By this time, the Japanese invasion force of about 150,000 men were down to about 53,000 men, with Chinese reinforcements arriving every day.^[252] Most of the Japanese were suffering from hunger, frostbite, and snow-blindness and some Japanese soldiers were so weakened by hunger that they were unable to defend themselves from tigers in the mountains.^[252] With the situation untenable, the Japanese retreated to the coast.^[251]

Stalemate

After the Battle of Byeokjegwan, the Ming army took a cautious approach and moved on Hanseong again later in February after the successful Korean defense in the Battle of Haengju.^[255] The two sides remained at a stalemate between the Kaesong to Hanseong line for the next couple of months.

Ming officials noted the supply issues in Korea. The records by Qian Shizhen noted that even after the Siege of Pyongyang, the Ming forces were already stalled for nearly a week due to the lack of supplies, before moving on to Kaesong.^[256] As time went on, the situation only become more serious. When the weather warmed, the road conditions in Korea worsened, as numerous letters from Song Yingchang and other Ming officers attest, which made resupplying from China itself also a tedious process.^[257]

By mid April 1593, faced with ever-greater logistical pressure from a Korean naval blockade of Yi Sun-sin, in addition to a Ming operation that managed to burn down a very significant portion of the Japanese grain storage,^[26] the Japanese broke off talks and pulled out of Hanseong.

Second siege of Jinju

Toyotomi Hideyoshi was especially determined to take Jinju and ordered that the previous Japanese failure to take the city be avenged.^[258] Ukita Hideie led 90,000 Japanese troops to take Jinju, making it the largest mobilization of Japanese forces for a single operation in the entire war.^[258] The Koreans, not knowing where the Japanese were going, divided their forces, with Kim Ch'ŏnil commanding the garrison of 4,000 soldiers at Jinju, who were joined by volunteers, guerrillas, a small Chinese force, and a large number of civilians including women and children, making for a total of about 60,000.^[259] On 20 July 1593, the Japanese began to construct wooden shields to allow them to advance against the walls.^[260] To the west were Konishi Yukinaga with 26,000 men, and to the north were Kato Kiyomasa with 25,000, while Ukita Hideie commanded the reserve of 17,000.^[260] On 21 July 1593, the Japanese attacked, breaking the dyke that filled the moat around Jinju, while the samurai advanced under their wooden shields, to be stopped by Korean fire arrows, cannonballs, and arquebuses.^[258] On 23 July, the Japanese attacked with wooden siege towers, which were knocked down by Korean cannon fire.^[160] On 25 July, under a flag of truce, Ukita sent a messenger to Kim, telling him that the Japanese would slaughter 10,000 Korean peasants whom they had taken prisoner if Jinju did not surrender at once, but Kim refused, and so 10,000 Korean peasants were beheaded.^[261]

The Japanese attacked with armored carts called "tortoise shell wagons", which allowed the Japanese to advance up to the walls, where the sappers would pull out the stones. But as a Japanese account complained: "They tried to attack, but from inside the castle, pine torches were thrown that set the grass alight. The soldiers inside the tortoise wagons were also burned and retreated".^[258] On 27 July, the Japanese again attacked with the "tortoise shell wagons", but this time, there was a heavy thunderstorm that prevented Korean attempts to incinerate the Japanese by dropping torches soaked in fat.^[161] The Japanese sappers broke down a section of the wall and a great rush broke out with the samurai pushed each other down as it was a great honor to be the first samurai to enter a fortress.^[161] The Korean garrison was out of ammunition and were short of swords, so many Koreans fought with wooden sticks against the onrush of samurai armed with katanas.^[161]

As usual, the Japanese took no prisoners, killing almost everyone, both military and civilian, and the Nam River ran red with blood as thousands attempted to swim across it, only to be cut down by the samurai waiting on the other side.^[161] Korean accounts mention that almost all of the 60,000 soldiers in Jinju were killed while Japanese accounts mention the samurai sent 20,000 heads back to Japan after their victory.^[161] Jinju was taken only for symbolic purposes, and instead of advancing, the Japanese force at Jinju retreated back to Busan as there was a larger Chinese force to the north.^[262]

Negotiations and truce between China and Japan (1594–1596)

There were two factors that triggered the Japanese to withdraw: first, a Chinese commando penetrated Hanseong and burned storehouses at Yongsan, destroying most of what was left of the Japanese troops' depleted stock of food. Secondly, Shen Weijing made another appearance to conduct negotiations, and threatened the Japanese with an attack by 400,000 Chinese. The Japanese under Konishi Yukinaga and Katō Kiyomasa, aware of their weak situation, agreed to withdraw to the Busan area while the Chinese would withdraw back to China. A ceasefire was imposed, and a Ming emissary was sent to Japan to discuss peace terms.^[263] For the next three years, there was little fighting as the Japanese retained control of a few coastal fortresses, with the rest of Korea being controlled by the Koreans.^[264]

By 18 May 1594, all the Japanese soldiers had retreated to the area around Busan and many began to make their way back to Japan. The Ming government withdrew most of its expeditionary force, but kept 16,000 men on the Korean peninsula to guard the truce.

Once peace negotiations between China and Japan finally got underway, Chinese negotiators gave the Ming emperor the mistaken impression that he was about to deal with a minor state that had been subdued by war. Furthermore, they conveyed the idea that the Japanese regent, Toyotomi Hideyoshi, was prepared to become his vassal. Under such conditions, the Chinese sought to resolve the issue in their favor by including Japan in their tributary system of foreign relations. They would establish Hideyoshi as king of Japan and grant him the privilege of formal tribute trade relations with the Ming dynasty.

In Japan, Hideyoshi's negotiators apparently led him to believe that China was suing for peace and was ready to accept him as their emperor. Thus, Hideyoshi issued the demands of a victor; first, a daughter of the Ming emperor must be sent to become the wife of the Japanese emperor; second, the southern provinces of Joseon must be ceded to Japan; third, normal trade relations between China and Japan must be restored; and fourth, a Joseon prince and several high-ranking government officials must be sent to Japan as hostages.

Bargaining from such fundamentally different perspectives, there was no prospect whatsoever for success in the talks. Early in 1597, both sides resumed hostilities.^[70]

Problems with Joseon defense policies

Korean scholar-official Yu Sŏngnyong observed, "not one in a hundred [Korean generals] knew the methods of drilling soldiers";^[265] rising in rank depended far more on social connections than military knowledge.^[266] Korean soldiers were disorganized, ill-trained, and ill-equipped,^[266] and they had been used mostly in construction projects such as building castle walls.^[70]

Local officers were forbidden from responding to enemy activity outside of their jurisdiction.^[267] They were required to wait for the arrival of a higher-ranking and centrally-appointed general with a newly mobilized army to take command, hindering flexibility.^[267] The appointed general often came from an outside region, and was likely unfamiliar with the natural environment, the available technology, and manpower of the region in question.^[267]

The Korean court managed to carry out some reforms, but they remained problematic. For example, the military training center established in 1589 in Gyeongsang Province recruited mostly men either too young or too old to be good soldiers, augmented by some adventure-seeking aristocrats and slaves buying their freedom, because able-bodied men of the right age, targeted by the policy, had higher priorities such as farming and other economic activities.^[267]

The dominant form of Korean fortress was the sanseong ("mountain fortress"),^[268] which consisted of a stone wall that continued around a mountain in a serpentine fashion.^[87] These walls were poorly designed with little use of towers and cross-fire positions and were typically of a diminutive height.^[87] It was wartime policy for these fortresses to serve as refuge castles and for civilians to evacuate to one.^[87] Those who failed to do so were assumed to be collaborators.^[87] The policy was largely ineffective because the fortresses were out of reach for most refugees.^[87]

Military Training Agency

Originally, the military system in Joseon was the Yangin Gaebyeongje (양인개병제). Able-bodied men worked in agriculture during the summer and trained for defense in the winter. Joseon divided these Yangin soldiers into five guards called Owi (오위, 五衛). However, as time went by, instead of receiving military training, the Yangin soldiers started paying money to avoid military service, and by the end of the 16th century, the actual number of soldiers that could be fielded was greatly reduced.^[269] During the early Joseon period, the Naegeumwi (금군인 내금위), Gyeomsabok (겸사복), and Urimwi (우림위) were responsible for the protection of the king.^[269]

As the number of Royal Guards decreased throughout the 16th century, the Training Command was established during the Imjin War. Its members were professional soldiers who received salaries and were entrusted with the task of protecting the king.^[269] Eventually, to overcome the war, a new military camp was established, and that was the Military Training Agency (훈련도감). The Training Command was also known as "Yeonhachinbyeong" (연하친병), which means a unit that directly guards the king under his supervision. They initially guarded the temporary residence of King Seonjo in Jeongneung-dong, but later protected the king in the palace itself.^[269]

In July 1593, Luo Shangzhi (駱尚志) was entrusted with the training of Huap'o cannons (화포, cannons). Luo was a skilled general of the Ming Dynasty, and focused on developing artillery forces (Pogun, 포군). The Training Headquarters was established in August, and a conscription system (Mobyeongje, 모병제) was implemented to operate it as a reserve army. They also acquired the book Jixiao Xinshu written by the Ming general Qi Jiguang to establish a training method based on the Samsubyeong (삼수병) system. The Samsubyeong system divided soldiers into three categories: Salsu (살수), who primarily used swords, Sashu (사수), who primarily used bows, and Posu (포수), who primarily used firearms. Among them, the Posu soldiers were the largest in number and played a major role.^[269]

When the existing military system (군제, 軍制) collapsed during the war, the Training Headquarters was established as a policy to address the situation. At that time, based on the suggestions of military commanders such as Ryu Seong-ryong, who held military command as the Three Provinces Military Inspector, the Training Manual was established with a focus on relieving the hungry and cultivating elite soldiers, providing a monthly salary of 9 dou and organizing them as specialized troops in artillery, combat, and marksmanship according to the Zhejiang Military Strategy in the military treatise "Gihyo Sinseo." Therefore, the Training Manual Army was organized as a specialized unit of the Three Provinces troops, with a focus on the principles of "treating many as treating few" and emphasizing "clear responsibilities and disciplined squads" based on the fundamental spirit of "Gihyo Sinseo." However, although it was organized as a specialized unit of the three types of soldiers, it was primarily organized around artillery for overcoming the Imjin War. Therefore, the Military Training Agency was initially established as artillery and later incorporated the Volunteer Corps as assassins and included gatekeepers and archers, and the organization as a three-type soldier was achieved after June of the 27th year of King Seonjo's reign.^[270]

The Military Training Agency was a temporary military camp that divided the national army into three types and trained them professionally to overcome the Imjin War. However, it gradually became a permanent military camp for the defense of the capital after the restoration.^[270]

Initial offensive

Initially, the Japanese found limited success, being largely confined to Gyeongsang Province and only launching numerous raids to harass and weaken the Korean defenders. In the early autumn of 1597, the Japanese began a more focused and sustained advance. The Japanese planned to attack Jeolla Province in the southwestern part of the peninsula and eventually occupy Jeonju, the provincial capital. Korean success in the first siege of Jinju in 1592 had mostly saved this area from devastation during the first invasion. Two Japanese armies, under Mōri Hidemoto and Ukita Hideie, began the assault in Busan and marched towards Jeonju, taking Sacheon and Changpyeong along the way.

Siege of Ulsan

Main article: Siege of Ulsan

By 29 January 1598, the Joseon and Ming allied forces achieved victory in Jiksan and pushed the Japanese further south. After the news of the loss at Myeongnyang, Katō Kiyomasa and his retreating army looted Gyeongju, the former capital of Unified Silla. The Japanese forces sacked the city and many artifacts and temples were destroyed, most prominently, the Bulguksa, a Buddhist temple. Ming and Joseon forces continued to harass the Japanese, who then withdrew further south to Ulsan.^[290]

Yi Sun-sin's control of the areas around the coast of Jeolla permitted no supply ships to reach the western side of the Korean Peninsula, into which many extensive river tributaries merge. Without provisions and reinforcements, the Japanese forces were constrained to the coastal fortresses, known as wajō, that they still controlled. The advancing Ming forces attempted to take advantage of this situation by attacking Ulsan. This siege was the first major offensive from the Ming forces in the second phase of the war.

The effort of the roughly 7,000-man Japanese garrison of Ulsan was largely dedicated to fortification in preparation for the expected attack. Katō Kiyomasa assigned command and defense of the base to Katō Yasumasa, Kuki Hirotaka, Asano Nagayoshi, and others before proceeding to Sosaengpo near Ulsan.^[291] The Ming army's first assault on 29 January 1598, caught the Japanese army unaware, still encamped, and largely outside Ulsan's unfinished walls.^[292]

A total of around 36,000 troops with the help of singijeons and hwachas nearly succeeded in sacking the fortress, but reinforcements under the overall command of Mōri Hidemoto came across the river to aid the besieged fortress.^[293] Although the Japanese garrison was short of supplies, the Ming commander, Ma Gui, judged the situation to be going against them, because more and more Japanese forces began to arrive from the surrounding area and the allied forces were quickly becoming outnumbered.^[294] Ma Gui ordered a retreat, but confusion set in, and matters were further complicated by heavy rainfall and harassing attacks by the Japanese. The Chief Superintendent Yang Hao panicked and left hastily for Hanseong ahead of the army.^{[295][26][294]} The general retreat turned into a chaotic rout, of which the Japanese took quick advantage by attacking the retreating Ming and Joseon forces.^[294] The retreating Ming and Joseon forces suffered 20,000 losses.^[35]

Final allied offensive of 1598

After the siege at Ulsan, the two sides remained in a stalemate for the next several months. Xing Jie decided that they would require further reinforcements to launch a final large offensive to permanently remove the Japanese presence on the Korean Peninsula.^{[citation needed]}

Reinforcements from China began to pour in through most of mid-1598, with Chen Lin and Deng Zilong and their navy arriving in May. By September 1598, the Ming presence in Korea had swelled to 75,000 overall, the largest at any point in the war.^{[citation needed]}

Xing Jie divided his forces into four groups, with Ma Gui leading the offensive against Ulsan yet again, Li Rumei leading the offensive against Sacheon, Chen Lin commanding the navy, and Liu Ting and Yi Sun-sin coordinating a land-sea effort against Suncheon. Just before they set out, however, news came that Li Rusong was killed by Mongolian tribesmen in Liaodong. Xing Jie decided then to remove his emotionally weakened brother, Li Rumei, in favor of Dong Yiyuan.^{[citation needed]}

In June 1598, after Commander Konishi Yukinaga raised concerns about the supply situation and limited prospects for further territorial gains in the peninsula, 70,000 troops were withdrawn back to Japan, with only 60,000 left behind to guard the territory still under Japanese control. These forces were mostly Satsuma soldiers of the Shimazu clan under commanders Shimazu Yoshihiro and his son, Tadatsune.^[296] Kato Kiyomasa remained in command of the defenses of Ulsan while Konishi Yukinaga himself commanded the defenses at Suncheon. The forces at Sacheon and Ulsan continued to be engaged in a military deadlock in the months that followed.^{[citation needed]}

At Ulsan, Kato Kiyomasa defended the castle with 10,000 Japanese soldiers.^[297] In September 1598, 29,500 Ming and Joseon troops tried again to capture Ulsan Castle, but all their attempts were repulsed by the Japanese. The Ming and Joseon forces withdrew with heavy losses.^[34]

Death of Hideyoshi

In the fall of 1598, following the successful Japanese defense at the battles of Sacheon, Ulsan, and Suncheon, the Ming, Joseon, and Japanese forces were locked in a military stalemate in the south of the peninsula.^[34] After the death of Toyotomi Hideyoshi, the Council of Five Elders, in late October, issued orders for the withdrawal of all forces from Korea. Hideyoshi's death was kept a secret by the council to preserve the morale of the army.

Battle of Noryang

The Battle of Noryang was the final, largest, and bloodiest battle in the war.^[301] A Japanese fleet of approximately 500 ships, under Shimazu Yoshihiro, was assembled.^[24] It prepared to link up with the blockaded fleet under Konishi Yukinaga, and together withdraw via Busan back to Japan.^[24]

The Korean navy under Yi Sun-sin discovered the Shimazu fleet anchored in the narrow strait of Noryang. Noting the narrow geography of the area, Ming general Chen Lin, who led Deng Zilong and Yi Sun-sin,^[35] made a surprise attack against the Japanese fleet, under the cover of darkness on 16 December 1598, using cannon and fire arrows.^{[citation needed][dubious – discuss]}

By dawn, more than half of the Japanese fleet was scattered and destroyed. During the pursuit of the remaining Japanese ships, both Yi Sun-sin and Deng Zilong were killed.^[302] Despite suffering high casualties,^{[citation needed][dubious – discuss]} the battle was a great victory for the Ming and Joseon forces and a crushing defeat for the Japanese,^[4][6] who lost about half of their navy,^[303] and suffered the deaths of thousands of their men.^[304]

Strategically, the Japanese attained their objective by allowing Konishi Yukinaga, who was earlier blockaded by the Ming and Korean forces, to leave his fortress on 16 December with his men and withdraw unopposed by sailing through the southern end of the island Namhaedo, bypassing both the Noryang Strait and the battle, at the cost of betraying fellow Japanese generals. Konishi Yukinaga, Shimazu Yoshihiro, Katō Kiyomasa, and other Japanese generals of the Left Army, congregated in Busan and withdrew to Japan on 21 December. The last ships damaged sailed to Japan on 24 December, bringing an end to six years of war.^{[citation needed][dubious – discuss]}

Losses and gains

Contrary to Hideyoshi's goals, the Japanese invasions of Korea significantly weakened the Toyotomi clan's power in Japan. After Hideyoshi's death, his young son Toyotomi Hideyori became head of the Toyotomi clan. Additionally, as the western-based daimyos of Kyushu and western Honshu contributed the majority of the forces used during the Korean conflict, the conflict bolstered the relative strength of the mostly eastern-backed forces of Tokugawa Ieyasu. Tokugawa would go on to unify Japan and establish himself as shogun in 1603, following the decisive Battle of Sekigahara.^[311]

Ming China was also left with a heavy financial burden. Falling tax revenues, troop desertions, a flow of foreign silver which brought unexpected problems to the Chinese economy, poor granary supervision and harsh weather eventually culminated in the collapse of the Ming dynasty.^[312] The Manchus established their rule over China as the Qing dynasty in 1644.^[313] However, the sinocentric tributary system that the Ming had defended continued to be maintained by the Qing, and ultimately, the war resulted in a maintenance of the status quo—with the re-establishment of trade and the normalization of relations between all three parties.^[314]

Given that the conflict was fought in Korea, Korea suffered the most damage of the three participants.^[315] It lost much of its military strength and civilian population, had numerous cultural heritage sites damaged or destroyed, and many of its technological advancements pillaged.^[31] In many ways the invasions proved to be more devastating than any other event in the nation's history.^[314] The peninsula suffered a reduction of arable land to 66% of the prewar total,^[316] greatly hurting Korea's mainly agricultural economy;^[70] in the years that followed, famine, disease, and rebellions were widespread throughout Korea.^[315] In Gyeongsang Province alone 90% of the land under cultivation was destroyed.^[317] Significant losses of historical archives, cultural and scientific artifacts (such as the Ja-gyuk-roo water clock^[318]), and skilled artisans resulted in a waning of Korean science.^[319] The Korean royal palaces of Gyeongbokgung, Changdeokgung, and Changgyeonggung were burned down, and Deoksugung was used as a temporary palace. The Baekjeong took advantage of the lack of internal security brought on by the invasions, and set fire to changnye – Korean government offices – in which census ledgers had been kept.^[320] The destruction of land and census registers made fiscal recovery difficult since taxation and corvée labour were based on them. The government was forced to trade rank and titles in order to obtain grain, using a practice called napsok pogwan^[317] – appointment through grain contributions – and the yangban elite, which was exempt from household taxes, exploited the occasion to increase its landholdings, thereby further depriving the central government of taxes raised on property.^[321]

George H. Jones, estimated that total casualties – both military and civilian – were one million,^[322] and combat casualties were estimated at between 250,000 and 300,000.^[323] A total of over 100,000 Japanese,^[8][23] 185,000 Korean and over 29,000 Chinese troops were killed, and an estimated 50,000 to 60,000 captives were taken by the Japanese throughout the war.^[21] Among those captured, a total of 7,500 were later returned to Korea through diplomatic means at the conclusion of the conflict.^[324] A large portion of the remaining captives were sold to European traders—mainly Portuguese in Macau, who then resold them throughout Southeast Asia.^[325][326]

Although Korea suffered the most of the three combatants, there were some significant technological and cultural transfers that resulted from the war. Japanese swords, which were sometimes collected in the battlefield from dead Japanese soldiers, would inspire some of the basic designs of later Korean swords such as the hwando. Arquebuses, which the Joseon court had initially dismissed as ineffective and useless due to their low rate of fire, were rapidly adopted during and after the war by the Joseon military and domestic production began as early as 1593.^[327] Some scholars believe that the reason the Joseon-Ming Army was not easily defeated in 1597 was in part due to the widespread adoption of arquebuses in the Joseon military.^[328]

In Korea, many of the first converts to Catholicism were Korean captives in Japan, and records indicate more than 7,000 Korean captives converted from 1594 to 1598.^[329] Spanish missionary Gregorio de Céspedes was a prominent driver of this missionary work, and was also the first recorded Westerner to arrive in Korea and the only European eyewitness to the war.^[329]

Chili peppers, one of the most important ingredients in modern Korean cuisine, were also introduced to Korea during the war.^[329] At the time, they were known as "Japanese mustard", "southern barbarian herb" and "Japanese herb."^[329]

The captives brought to Japan, provided Japan with many cultural and technological innovations.^[21] In the years that followed, Japanese pottery and art advanced and developed a significant similarity to their Korean counterparts.^[182] Japanese typography advanced with the adoption of Chinese fonts.^[330] Because Korean pottery was highly prized in Japan, many Japanese lords established pottery-producing kilns with captured Korean potters in Kyushu and other parts of Japan.^[331] The production of Arita porcelain in Japan began in 1616 at the town of Imari with the aid of Korean potters who had been enticed to relocate there after the war.^[331]

Furthermore, Neo-Confucianism, which had originated in China and spread to Korea, was introduced to Japan because of the invasions. Many Korean scholars who were captured during the war by the Japanese would later become tutors of prominent Japanese daimyo.^[332] Furthermore, many classical Confucian texts were captured during the early stages of the war and taken back to Japan.^[333]

War atrocities

In the second invasion, Hideyoshi's orders were:

Mow down everyone universally, without discriminating between young and old, men and women, clergy and the laity—high ranking soldiers on the battlefield, that goes without saying, but also the hill folk, down to the poorest and meanest—and send the heads to Japan.^[334]

Scorched earth policies were often employed: over 60% of farmland was destroyed and burned, and farm animals were slaughtered to prevent their use by Joseon or Ming forces.^[144] Outside of the main battles, raids to acquire food and supplies from civilians were common.^[335] Captured prisoners were often mistreated or worked to near-death by starvation and neglect.^[336] The Japanese collected the ears and noses of dead soldiers as proof of their exploits on the battlefield and as a record of casualty counts.^[337] The high casualty rate of the Joseon and Ming forces, and the large number of ears collected during the campaign was enough to build a large mound near Toyotomi Hideyoshi's Great Buddha, called the Mimizuka ("Mound of Ears").^[338]

Korean armies were also known to forcefully acquire food and supplies from civilians, both on an individual and organized level.^[151] Korean bandits and highwaymen also took advantage of the chaos during the war to form raiding parties and rob other Koreans.^[339]

According to Stephen Turnbull, the Ming forces were often no better than the Japanese in the amount of destruction they caused and the degree of the crimes they committed.^[305] After the immediate Japanese military threat was neutralized, Turnbull states that the Joseon desire for the Ming armies to quickly withdraw from Korean territory was a contributing factor to the pace of the eventual peace resolution.^[305]

Rape was common during the war, and Korean women were indiscriminately assaulted and brutalized by Japanese, Chinese and Korean soldiers throughout the conflict.^[340] Records from the war indicate that Japanese soldiers "frequently decapitated all the young men of a locale and carried off all the attractive women—along with the goods they had stolen—on the backs of horses and oxen" and descriptions claim that the priorities of Japanese soldiers during the conflict were "granaries, understanding local geography, and beautiful women."^[341] Meanwhile, Joseon soldiers, such as those led by Kim Myŏn, captured not only Japanese soldiers but also many Korean women who had "been taken prisoner by the enemy."^[341] Records also indicate that Ming Chinese and Joseon Korean forces committed rape against the civilian populace during the conflict.^[340]

Legacy

The invasions are seen as the first Japanese attempt to become a global power.^[314] The partial occupation of Korea developed the Japanese concept that Korea belonged within Japan's sphere of influence, and the Japanese leaders of the late 19th and the early 20th centuries used the 1592–1597 invasions to reinforce the justification for their 20th-century annexation of Korea.^[342] Yi Sun-sin also served as an inspiration for Imperial Japanese admirals during the 19th and 20th centuries, as they often stressed the importance of studying and utilizing his battle tactics to further strengthen their own navy.^[343]

In China, the war was used politically to inspire nationalistic resistance against Japanese imperialism during the 20th century.^[314] In Chinese academia, historians list the war as one of the Wanli Emperor's "Three Great Punitive Campaigns".^[314] Contemporary Chinese historians often use the campaigns as an example of the friendship that China and Korea shared.^{[citation needed]}

Korea gained several national heroes during the conflict, including Yi Sun-sin and Chen Lin.^[314] The widespread guerilla warfare fought by various righteous armies, which spearheaded the Korean civilian resistance against the Japanese invasion, had a significant impact on the common Korean populace's conceptions of nationhood and identity. The invasions and subsequent efforts by the local gentry to rally the commoners had a critical impact on perceptions of national identity in Korea, as the gentry were recorded to have sent many letters and declarations against the Japanese invaders and called upon shared Korean history, culture and beliefs to unite the Korean people.^[344]

On 12 October 2025, descendants of Joseon and Japanese commanders who participated in the Imjin War gathered for the first time in Korea, where the descendants of Japanese commanders apologized for their ancestors' brutality against Joseon citizens.^[345]