Toyotomi Hideyoshi's Korean Invasions: the Bunroku Campaign (1592-93)

The greatest war that Korea experienced before modern ages was Japan's invasions carried out by Toyotomi Hideyoshi. Hideyoshi, who made his way from a mere peasant to the rank of the chancellor by his wit, is one of the most popular historical characters in Japan. To Koreans, however, he is known as Pungsinsugil and is nothing but an archenemy.
When, in 1587, the lord of Tsushima came to pledge allegiance to Hideyoshi at Hakata, Kyushu, Hideyoshi charged him with the task of persuading the Korean King to pay tribute to Hideyoshi. Hideyoshi, then on his campaign to conquer Kyushu, was already boasting that he would invade Korea and China. To him, Korea was nothing but a foothold on his way to conquer China.
To Tsushima, which was in the strait between Japan and Korea and did not abound in resources, the only way to survive was mediate trade between Japan and Korea. Pressed by Hideyoshi, however, its lord, So Yoshitoshi, visited Korea himself and won its agreement to send an envoy in 1590.
Prior to the despatch of the envoys, gifts were exchanged between the two countries, in which Japan sent Korea an arquebus. Firearms, first brought to Japan by a Portuguese vessel in 1543, had been much improved in the age of the warring states and transformed the battlefield tactics in Japan. The arquebus, however, drew no attention in Korea, which had been in time of peace for centuries.
In 1590, the Korean envoys arrived in Japan. Hideyoshi returned to Kyoto after successfully ending the siege of Odawara. The envoys, who had been kept waiting for three months, were received with a simple feast. Moreover, after the ceremonial greetings, Hideyoshi left the room and came in with an infant (his heir Tsurumatsu) in his arms. When the baby wet his clothes, Hideyoshi handed the boy to the nurse with an unscrupulous laughter, showing his complete lack of respect to the envoys.
As was expected, the letter from the Korean King was not one of homage. Seeing that, Hideyoshi would not give a reply. After much trouble the envoys obtained a reply. But it was full of insults to the Koreans and boasted of Hideyoshi's intention of conquering China, in which he expected Korea's cooperation as if it were a matter of course.
When the ambassadors returned, a council was held in the presence of King Sonjo to discuss the course to take. In the political circles of Korea, however, strife between the Eastern Faction and the Western Faction affected everything. When the senior ambassador warned that Japan's invasion was a certainty, his deputy contradicted him. In the end, the council concluded that Japan would not launch an invasion for the time being.
Meanwhile, Hideyoshi's publicized intention of invading Korea, in turn, stunned the lords and generals. But nobody dared to raise an objection and when the two most powerful daimyo Tokugawa Ieyasu and Maeda Toshiie expressed their approval, the matter was fixed. It seems significant that neither Tokugawa nor Maeda was required to send troops to the expedition.
In the end of 1591, Hideyoshi built in only two month Nagoya Castle in Northern Kyushu to be used as a base of the expedition. From this place, Pusan at the southern end of the Korean Peninsula is only a day's voyage via Tsushima.
In the morning of April 12th, 1592, when a Japanese fleet was sighted, Won Kyun, the Right Naval Commander of Kyongsang, took it for a convoy on a trade mission. Towards the evening, a further report came of a great fleet and Won Kyun at last realized that something very serious was happening. His colleague, the Lef Naval Commander of Kyongsang, fled after scuttling his fleet and destroying all the armaments and provisions. Won Kyun in his turn sought saftey with only four ships. Thus the Japanese armada successfully disembarked its army on the Korean Peninsula without resistance.
In the early morning of April 13th (lunar calendar), 1592, the Japanese began its attack on Pusan. In no time Pusan fell and Tongnae behind it (the headquarters of the region) followed it.
The Japanese army led by Konishi Yukinaga marched north toward the capital Seoul (then called Hansong). They beat the meager defenders at Sangju and at Ch'ungju, little reduced from its original strength of 18,000, faced the 8,000-strong Koreans. Korean cavalry was put to rout by the volleys of the Japanese arquebus. The second army under Kato Kiyomasa burnt Kyongju.
The report reached the capital and the King left Seoul on April 30th for Pyongyang. When the Japanese army drew near, the defenders of the capital fled. On May 3rd, the Japanese seized Seoul.
Nothing seemed to stop the advance of the Japanese. They marched north and soon approached Pyongyang. The King fled further north toward the border with Ming and on June 15 the Japanese occupied Pyongyang.
But, naturally, Korean volunteers rose everywhere and to suppress it the Japanese burnt the villages. The Japanese administration of the occupied land stood on a very precarious basis.

The Japanese swept over the Korean Peninsula in a short time but Cholla (southwestern part of the Korean Peninsula) was not in her control. After the Kyongsang navy fled without fighting, the Cholla navy was preparing for a campaign under the Left Naval Commander of the Cholla Province, Yi Sun-shin.
On May 4, the day after the Japanese occupation of Seoul, Yi Sun-shing sailed at last eastward seeking the sight of the Japanese fleet. On May 7, he found the enemy at Okp'o (on the east coast of Koje Island) ordered to attack.
Superior as the Japanese were on land because of the sophisticated arquebus, they still relied on old tactics of boarding enemy vessels in sea battles. They were no match for the Korean fleet's gunfire from a distance. In the two-day battle, Yi Sun-shing sank many Japanese vessels.
Then, on May 29, Yi Sun-shin led a fleet including a newly constructed turtle ships and beat the Japanese fleet lured out of Sach'on Bay. The Korean fleet under him won further victories at the Battles of Tangp'o (June 2) and Tanghangp'o (June 5).
The Japanese were determined to deal with Yi Sun-shin in earnest. Yi Sun-shin, on his part, sought battle with the Japanese fleet in order to frustrate the Japanese advance on land into the Cholla Province.
On July 7, receiving reports from the local residents about the position of the Japanese vessels, Yi Sun-shin lured the enemy fleet in the strait of Kyonnaeryang into open sea. In the ensuing Battle off Hansando, he employed a crane's-wing formation and destroyed the Japanese thoroughly. Two days later, he beat the Japanese reinforcement at the Battle of Angolp'o.
While in the north Pyongyang was held by the Japanese since June 15, the command of the sea in the south waters was secure for the Koreans.

It was about this time that the great power Ming China entered the scene. Hideyoshi's intention of conquering China had reached the Ming court earlier and the news of the Japanese occupation of Seoul on May 3 arrived there on 19. The Ming army from Liaodong, crossing the Yalu and entering Korea in middle June in answering the plea of the Korean King, started operations in middle July and attempted to recaputre Pyongyang on July 16. But they were repulsed without difficulty.
Meanwhile, another Japanese army under Kato Kiyomasa detached to Hamgyong Province in the north-eastern part of the Peninsula took the two Korean princes prisoner with the cooperation of Korean dissidents (July 23). In early September, he even made a short-duration invasion into part of China (for once the Koreans were cooperative because they had been harrassed by the raids of the Jurchens).
But no sooner than Kiyomasa returned to Hamhung (September 7), the country just conquered turned back into a rebellion. The Japanese could hold a series of forts but could not control the Korean people.
Even in the south, critically important to the Japanese supply line, Admiral Yi's supremacy in the sea pushed back the Japanese control into a small area around Pusan. To break the situation, 20,000 Japanese army marched west and on October 4 arrived before the critical stronghold of Chinju. However, the garrison of only 3,800 gave a determined resistance and pushed back the Japanese. The defense commander Kim Shi-min who achieved this greatest Korean victory in the whole campaign was killed in the fierce battle. (By the way, the Koreans had 170 arquebuses of quality comparable to Japanese ones and put them into use for the first time.)
Winter was approaching. Considering the situation, the commander Konishi Yukinaga agreed to the Chinese proposal for negotiating peace brought by a mediator . At one time, negatiation might have led to partition of Korea between China and Japan but the demand of the Japanese were too much for the Chinese. In Novermber, the Chinese hardened his attitude and demanded the withdrawal of the Japanese troops and the return of the two captive princes.
The negotiations were broken off and in January, 1593, a huge Ming army of more than forty thousand attacked the Japanese in Pyongyang. It was not only the matter of the numbers. The heavy firepower of the Chinese cannon inflicted a severe damage to the Japanese. The Japanese were forced to withdraw in the snow-covered country all the way to Seoul.
The pursuing Ming army approached Seoul and the desperate Japanese countered this force. In the Battle of Pyokje lodging [Pyokje-yek, Byokchekwan] on January 26, the Ming cavalry without firearm suffered a crushing defeat and was forced to retreat.
The Japanese tried to retake Haengju, north to Seoul, which had been recaptured by the Koreans shortly before the Battle of Pyokje. On February 12, the 30,000-strong Japanese army attacked Haengju but the mere 4,000-strong garrison repulsed the attack with a desperate resistance. The defense of Haengju is regarded as one of the three great victories for the Koreans, with the naval Battle of Hansando and the defense of Chinju as the other two.
Truce was negotiated and it was decided that the Japanese would evacuate Seoul and retreat to Pusan. On April 18, the Japanese left Seoul and in early June they withdrew to the area around Pusan.
The Japanese fortified such places around Pusan as Tongnae, Kimhae, Ungch'on, Koje Island and Kadok Island in view of a prolonged war. The Ming army watched them from such stations as Sach'on or Kyongju.
The Japanese set on a campaign to capture Chinju, a gateway to the Cholla province, with intentions of securing the south. The capture of Chinju, in which they failed the previous year, was an absolute imperative from Hideyoshi, who had grudgingly admitted the evacuation of Seoul. The Japanese committed a total of 90,000 in this campaign, an unparalleld number throughout the entire war. Starting the siege on June 22, they took the town. Long harassed by the guerrilla war of the Korean volunteers, the Japanese took this occasion to massacre 60,000 soldiers and civilians. There was no relief from the Ming army except for some vanguards.
Despite this victory, it was obvious now that there was not a faintest hope for Hideyoshi's great desire to conquer the great Ming. Hideyoshi left Nagoya in August and returned to Kyoto. By the end of the year, the Japanese army returned home leaving garrisons in a series of coastal castles.

上垣外憲一(1989, 2002): 文禄・慶長の役 空虚なる御陣
Turnbull, Stephen (2002): Samurai Invasion Japan's Korean War 1592-1598