Japanese Invasion of Korea

Japanese Invasion of Korea

Japanese warlord Toyotomi Hideyoshi dreamed of conquering China and launched two invasions of Korea, in 1592 and 1597, in order to do so. Although he ultimately failed, the wars inflicted terrible devastation on Korea. Because as its overlord the Ming dynasty in China sent a large army to aid Korea, the war also considerably weakened the Ming dynasty.

In the 16th century, Japan underwent constant civil wars as the Ashikaga Shogunate weakened and various feudal lords sought supremacy; in fact this period was called the “Warring States” abad in Japanese history. Hideyoshi was an ambitious general who rose from obscurity. By 1590, he had destroyed all rival lords and unified Japan, freeing him and his large army to conquer new lands.

His target was China and to reach China he needed passage through Korea. When Korea refused his demands he led an invading army of 160,000 men, landing on the southern tip of the peninsula and advancing northward. The inferior Korean army was overwhelmed, King Sonjo abandoned his capital city Seoul and fled, and his two sons were made captives.


The Korean cause was saved from complete ruin by the emergence of Admiral Yi Sun-sin, who built a fleet of “turtle ships,” the world’s first wooden ships with steel plating, which repeatedly defeated the Japanese navy, thus disrupting their supply lines. Meanwhile, China responded with 200,000 troops, who captured Pyongyang and pursued the Japanese forces southward until they only held the southern tip of the peninsula.

Peace negotiations proved fruitless and were broken off because China demanded that Hideyoshi acknowledge Chinese overlordship while Hideyoshi demanded a part of Korea to be ceded to him, the marriage of a Ming princess to the Japanese emperor, and Korean princes as hostages.

Undaunted, Hideyoshi launched a second invasion in 1597 but proceeded no farther than Korea’s two southernmost provinces because both the Koreans and the Chinese relief army were prepared. When Hideyoshi died in 1598 his army quickly returned home. In 1606, Tokugawa Ieyasu, the new shogun of Japan and Hideyoshi’s successor, made peace with Korea.

Admiral Yi Sun-sin in his turtle ships

The two Japanese invasions inflicted terrible sufferings on the Koreans. Whole areas were devastated and depopulated and many historical sites and libraries were burned. The Yi dynasty of Korea never fully recovered its authority and the country its prosperity.

The retreating Japanese moreover took many looted treasures and took as prisoners men with skills, most notably Korean potters, who built up Japan’s ceramics industry. Hideyoshi’s dream of ruling Japan died with him because his son was too young to rule, allowing another feudal lord, Tokugawa Ieyasu, who had not participated in the Korean campaigns, to seize power.

Finally the cost of the war weakened the already declining Ming dynasty in China. Additionally, the sending of a large army to Korea denuded southern Manchuria of Ming garrisons and paved the way for the rise of the Manchus.

Defending Korea

Early Yi Dynasty

building that remain from early Yi dynasty

The Choson or Yi dynasty was founded by General Yi Songgye (1335–1408; r. 1392–1408). Yi was a successful general of the declining Koryo dynasty that had ruled Korea for about 500 years. He staged a coup against his government in 1388 and four years later, with the support of the reform-minded Confucian scholars, proclaimed himself King Taejo of a new dynasty.

With the approval of the newly established Ming dynasty in China, to whom he rendered vassalage, he chose the dynastic name Choson, which means “morning serenity,” and moved his capital from Kaesong to Hanyang (present-day Seoul).

Besides the founder, the dynasty was well served by its third king, T’aejong (r. 1400–1418), and his son, Sejong (r. 1418–50), under whom it reached its zenith. The founders of the dynasty were firmly committed to Neo-Confucianism of the Zhu Xi (Chu Hsi) school that had been adopted as official in China since the Song (Sung) dynasty, 961–1289.


Korean Neo-Confucian scholars, who were the mainstay of the dynasty, aimed to create in Korea the idealized state exemplified by China’s sage rulers of the golden age, Kings Yao, Shun, Yu, and the founders of the Shang and Zhou (Chou) dynasties.

Much was achieved in the first half century of the dynasty in many fields. Learning and scholarship were esteemed and talented men were encouraged to enter government service. A National Academy was established in Seoul and state endowed schools were established in every county.

Three levels of state-supervised examinations based on Confucian texts and according to Neo-Confucian interpretations were held nationwide and most officials were chosen from the ranks of successful candidates. As in China, the study of history was highly esteemed and the state sponsored the writing of official histories.

Because of the high cost of importing block-printed books from China, Koreans invented movable type, the first in the world. Koreans had until now no written script and had used the Chinese written form exclusively, but because the structure of the Korean language was different from that of Chinese, King Sejong instigated the invention of a Korean alphabet, which was strictly phonetic, proclaimed in 1446. It was then called Hunmin Chongun and in the 21st century Hangul.

The Yi dynasty’s commitment to Neo-Confucian principles would gradually transform Korean society and end the dominance that Buddhism had exercised over Korean life during the Koryo era.

The inadequacies of Buddhism and the mismanagement of government and society under Buddhist influence were blamed for the economic and etika decline of Koryo. As a result Buddhism suffered severe decline during the Yi dynasty. Instead leaders actively inculcated Confucian etika principles.

They emphasized the proper rites and rituals of ancestor worship, filial piety, loyalty, proper social relationships, the patrilineal line of descent, and proper relationship between men and women. The union between a husband and wife was regarded as the mainspring of a stable society.

Whereas upper-class men previously could have several wives, who were not subject to a specified ranking order, under Confucian teachings, only one woman could be wife and mother of her husband’s heir, relegating other women of the household to concubines and their children to lesser importance.

Though subject to her husband, the wife had charge of the domestic sphere, and responsibility of providing the government with loyal subjects and the family with devoted sons. The public sphere was the husband’s domain.

In science and technology this kurun saw the invention or refinement of the sundial, the automatic water-driven clock, armillary spheres (miniature representations of the Earth, Moon, and planets in the form of skeletal globes), and the rain gauge. Medical books that included new knowledge were published and made widely available.

Since Confucians honored farmers as the backbone of society, farming was encouraged. Land reform and redistribution and the introduction of new agrarian methods from China greatly increased food production. Innovations included the introduction of new manure, crop rotation instead of letting fields lie fallow, irrigation, and autumn plowing.

Commerce played a decidedly secondary role in the early Yi era. Attempts by the government to introduce paper money and copper coins proved unpopular and people preferred the old method of using a type of cloth and grain as mediums of exchange. This remained true until the early 17th century, when increased commerce led to the acceptance of metal coins.

The policies and practices instituted by the founders of the Yi dynasty established the firm foundations that led to a period characterized by brilliant cultural and technical achievements. They also explain its longevity despite later setbacks.

Silla Dynasty

Silla Dynasty Map

The Silla dynasty was a Korean kingdom with origins in the southeast of the country, in the area around modernday Pusan (Busan). It is said to have begun in about 57 b.c.e. when the Saro tribe and its allies in that region established a confederation of the tribes, led by Pak Hyeokgeose.

However many historians feel that date was the invention of 12th-century Korean historians, as found in the Samguk Sagi, written by Kim Bu-sik, to try to show that the Silla predated their main rivals. The early years of Silla saw a rotated monarchy with members of the Pak, Kim, and Sok families sharing the title of ruler, although not using the title of king until later.

As the kingdom of Koguryo was emerging as a major power in northern and central Korea, Silla was taking over tribes in the south. Originally they only targeted the Saro tribe, taking tribute to the Mahan confederation as their vassal in 19 b.c.e.


However Silla grew dramatically in prosperity and many historians have seen this as the influence of many Chinese merchants who came to settle in the area and brought with them much resultant trade.

There were also influences from Japan—the envoy that took the tribute to Mahan in 19 b.c.e. was of Japanese ancestry. In the year after this mission, the king of Mahan died and although Silla sent over a delegation for the funeral, they rapidly drew up plans to take land from Mahan and enlarge their area.

In 250 c.e. the Mahan confederacy, which had controlled much of central southern Korea, was finally absorbed, not by Silla, but by the kingdom of Paekche (Baekje), which had a common border with Silla.

Silla dynasty artifact

This was initially thought to be dangerous as it left the Korean Peninsula under the control of three kingdoms, Silla, Paekche, and Koguryo, with little in the way of buffer states that had existed beforehand. Silla and Paekche feared invasion from the emerging power of Koguryo, which had ejected the last Chinese base in 313.

To counter this threat, Kim Naemul (356–401) of Silla assumed the title of maripkan or king ensured that the succession to the throne was hereditary. The end of the rotating monarchy resulted in the ability to establish a more centralized administration, which adopted many of their methods of government, customs, and some Chinese culture.

Initially Silla sided with Koguryo to attack Paekche, which had been aiding Japanese pirates. However when Koguryo moved its capital south to Pyongyang in 427, and its focus also moved south, Koguryo and Silla had to form an alliance. Silla also built up trade ties with Japan.

King Peopheung (r. 514–540) established Buddhism as the state religion of the kingdom of Silla and embarked on military expeditions that eroded the power of the nonaligned tribes in the region.

Silla dynasty crown

His successor, King Jinheung (r. 540–576), enlarged the army and used it to help Paekche take lands around modern-day Seoul. However in 553 he decided that his forces were strong enough to seize the whole area for itself, ending the 120-year alliance of convenience between Silla and Paekche.

The war in 553–555 led to Silla’s massively enlarging its landholdings, with Paekche forced to cede over half of its territory. This was followed by a long period of peace when scholars in Silla devoted much time to Buddhism.

King Pak-jong, who ascended the throne in 576, abdicated to become a monk and his wife became a nun. A considerable part of the wealth of the country was sent in missions of tribute to China, which weakened Silla economically but bought them a firm alliance.

Sejong - Korean King

Sejong - Korean King

The fourth king of the Yi dynasty of Korea, King Sejong, ruled from 1418 until his death in 1450 was one of the most famous rulers in Korean history, and one of only two to have the title “the Great.” During his reign there was stability in Korea, and also major advances in literature and the arts, in particular the introduction of a new script.

King Sejong was born on May 6, 1397, the third son of King Taejong (r. 1400–18). When he was 10 years old, he gained the title Grand Prince Chunghyeong. He ascended the throne in 1418, at the age of 21, and his oldest brother, Prince Yangnyong Taegun, was overlooked to become king because the royal family regarded him as too headstrong and impetuous and the second brother had predeceased his father.

One of King Sejong’s first moves was to secure the southern parts of Korea against attacks by Japanese pirates who were launching raids on Korean coastal villages. He did this by sending soldiers to Tsushima, where they fended off seaborne attacks.


In the north, Sejong oversaw the building of four castles and six military posts, which were built to prevent problems with the new Ming dynasty in China. He also encouraged many people from central Korea to move to the north to help build the economy of the region and ensure continued stability.

King Sejong’s greatest legacy to Korea was his introduction of the Han’gul script. The Chiphyonjon, a royal institute that conducted research on behalf of the king, introduced this new script.

The institute compiled a long series of official histories of Korea and treatises on Confucian ideas and also organized many history talks increasing the knowledge of the royal family and the nobility in the history of Korea.

With no suitable Korean script, the Koreans had been using Chinese characters or Hanja to express their language. With Han’gul, although many Chinese words remained, it was possible to have new characters that better reflected Korean pronunciation and inflexions.

The new script was purely phonetic and is believed to have developed from Sanskrit, or even Tibetan. Sejong would have likely come across these scripts while reading religious books.

Sejong statue

The new script was a move heavily opposed by many scholars, but Sejong, a linguist and an autocrat, pushed for Han’gul to become accepted. This gained Sejong the title “the alphabet king.” A dictionary was published soon afterward.

In 1420 after only two years on the throne, Sejong had established the Jiphyeonjeon or “Hall of Worthies” in the royal palace in Seoul, where he persuaded many visiting scholars to remain. During his reign scholars compiled 20 major works on Korean agriculture, astronomy, history, geography, mathematics, military history, science, pharmacology, and philosophy.

Of particular note were encyclopedias of Chinese and Korean medicine. During the 1440s King Sejong himself wrote a number of books. Yongbi Eocheon Ga (Songs of flying dragons) was written in 1445 and followed two years later by Seokbo Sangjeol (Episodes from the life of Buddha).

In June 1447 he wrote Worin Cheon-gang Jigok (Songs of the moon shining on a thousand rivers), a series of poems praising Lord Buddha, and in September of that year helped with the compilation of Dongguk Jeong-un (Dictionary of correct Sino-Korean pronunciation).

In terms of justice Sejong started a process of codifying the laws. He massively reduced the amount of corporal punishment that could be inflicted and established two levels of courts of appeal by which people under sentence of death could have evidence in their trial tested before further judges, and available for inspection by the king, prior to sentencing and execution.

Sejong is also credited with the invention of the rain gauge, self-striking water clock, and the sundial. Critics of Sejong point out the pervasive nature of slavery during his reign and that he did little (if anything) to help slaves.

Some had been sentenced to slavery for criminal actions, but most had been born into slavery and lived their lives in terrible conditions either as domestic hands in the cities or as farm laborers in the countryside. In addition, Sejong continued the system of court eunuchs, who wielded much power in the extravagant court.

King Sejong married Sim On (1395–1446) of Cheongsong, later awarded the title Princess Consort Soheon (or Sohon Shimn). They had eight sons and two daughters—the first son, Munjong, would succeed, followed by his son, Tanjong, and then the second son, Sejo.

Sejong and his first concubine, Kim Shinbin (1406–65), had six more sons. With his second concubine, Yang Hyebin, he had three further sons. His third concubine gave him another son, and his fourth and fifth concubines, another two daughters. King Sejong died in 1450 and was buried at Yong Nung.

His son Munjong succeeded him. A street in central Seoul is named after King Sejong, as is the Sejong Center for the Performing Arts. He also appears on the South Korean 10,000 won banknote. From King Sejong’s older brother descend the family of Syngman Rhee, who became president of South Korea from 1948 until 1960.

Koryo Dynasty

Koryo Dynasty

The kingdom of Koryo (or Goryeo) in Korea was named after the dynasty that ruled from the fall of the Silla dynasty in 935 c.e. until the Yi dynasty overthrew it in 1392. The English name Korea is derived from the word Koryo. The kingdom of Koryo was an empire until it was forced to take the status of a kingdom when dealing with the Yuan dynasty (1279–1368) in China.

The kingdom of Koryo traces its origins back to the weakening of Silla during a civil war in the early 10th century. Major rebellions against the Silla rulers had been led by Kung Ye, Ki Hwon, Yang Kil, and Kyon Hwon, with Kung Ye forming the kingdom of Hugoguryo (the Later Kingdom of Koguryo) and Kyon Hwon establishing Hubaekje (the Later Kingdom of Paekche). It was the first of these, the Later Kingdom of Koguryo, that would emerge as the kingdom of Koryo.

When Kung Ye led his rebellion against Silla, he wrested from their nominal control much of central Korea and established his capital at Kaesong (Songak) in 901. Soon afterward another rebel, Wang Kon (or Wanggeon, or Wang Kien), emerged to help the rebellion.

He was from a merchant family and drew support from nobles who had watched the stagnation of the Silla with horror. Kung Ye recognized the leadership qualities of Wang Kon and appointed him the prime minister of the new government based at Kaesong.


However in 918 Wang Kon overthrew Kung Ye and placed himself at the head of the rebellion. Wang Kon obviously realized that even though the Silla were weak, he did not initially have the military force capable of defeating them. As a result it was not until 934 that Wang Kon decided to attack the Later Kingdom of Paekche at Hongson (Unju).

Wang Kon’s victory was quick because in 935, Kyon Hwon surrendered to him. The Later Paekche king had designated his fourth son as his heir and this had annoyed his eldest son, Sin-gom, who drove him from the kingdom. Wang Kon easily overcame Singom’s army and the Later Kingdom of Paekche became a part of the emerging kingdom of Koryo.

In December 936 the Silla king, Kyongsun, realizing that his forces would be unable to defeat Wang Kon in battle, also surrendered and Wang Kon became the king of the Korean Peninsula, ruling from Kaesong.

Wang Ko, better known by his posthumous title, King T’aejo, decided to be magnanimous and gave exking Kyongsun the highest position in his new government, marrying a daughter of one of the Silla rulers, which helped legitimize his rule in the minds of many nobles.

Furthermore he left most of the nobles in charge of their lands. When he died, after a reign of only seven years, his son became King Hyejong (r. 943–945), and succession was unchallenged. For many people, their connection with the court was through a Buddhist hierarchy that controlled much of the countryside.

The first external challenge faced by the new Koryo dynasty was a series of invasions by the Khitan peoples to the north and the west of Korea. They controlled many of the lands on the north of the Yalu Rover and claimed to be descendants of the original leaders of Korea.

koryo army

The Koryo tried initially to conclude an agreement with the Khitan but soon realized that this tribe actually wanted nothing less than control of most of the Korean Peninsula. In China, the new Song (Sung) dynasty was entrenching itself in power and sought an alliance with the Koryo.

Realizing that they would soon have enemies on both sides of them, the Khitan attacked in 983, 985, and 989 in a series of raids across the Yalu River. They decided to invade the Korean Peninsula before the Chinese could conclude an alliance with Koryo, and in October 993 a large Khitan army, estimated by some historians as being 800,000, led by Hsiao Sun-ning, attacked Koryo.

The Koryo king, Songjong, took command of his soldiers at Pyongyang and held up the Khitan advance. Recognizing that the Khitan would not be able to win a long and protracted war in enemy territory, the Khitan negotiated a peace agreement and withdrew.

A similar persoalan arose in 1115 with the Jurchen (Manchu) tribe in Manchuria. The Jurchen leader had occupied southern Manchuria and proclaimed himself the emperor of China. They attacked the Khitan kingdom of Liao, and with help from the Sung, managed to destroy the threat of the Khitans sacking Liao in 1125.

The Jurchen then attacked the Song, who were forced to retreat to southern China. With the Koreans uncertain who was going to win this war, and worried the Jurchen might become too strong and decide to annex Korea, the Koryo kings were more careful in not getting involved in the war in China.

In 1126 there was a major dispute over the focus of the kingdom. One group wanted to keep the capital at Kaesong and preserve the status quo. The other, led by Myo Cheong, wanted the capital moved back to Pyongyang, which would allow Korea to expand to the north.

In 1135 the Myo Cheong rebellion failed. However 35 years later Jeong Jung-bu and Yi Ui-bang launched a coup d’etat against King Injong, who was exiled, and Myongjong became the next king, reigning until 1197. For much of that time he was a puppet who served the interests of contending generals such as Kyong Taesung (r. 1177–84).

In 1197 Choi Chungheon, another general, deposed Myongjong, and replaced the king with Sinjong (r. 1197–1204). He then ousted Sinjong and put Huijong on the throne. However Choi Chungheon deposed Huijong in 1211, and a new king, Kangjong, ruled for two years. Choi found the next king, Kojong, more compliant, and he outlasted Choi, reigning until 1259.

In 1202 Genghis Khan was elected leader of the Mongols and attacked first the Jurchen and then the Chinese. Mongols chased some escaping Khitan refugees to Pyongyang and in 1279, having conquered China, established the Yuan (or Mongol) dynasty, moving the capital of China to Beijing.

The Koryo kings decided not to challenge the power of the Mongols and tried to maintain some semblance of independence but at the same time dispatched tribute to the Mongols, sending royal hostages to Beijing, and some of the kings had to marry Mongolian women.

Three of the later Koryo kings, Chungnyol, Chungson, and Chungsuk, spent most of their time at the Mongol court, leaving little time to manage their own kingdom. It was a diplomatic balancing act but did ensure that the Mongols, with their well-known bloodthirst and penchant for revenge, did not pillage Korea in the way that other areas were destroyed by them.

However when the Mongol emperor of China Kubilai Khan, wanted to attack Japan in 1274 and again in 1281, the Koreans had to provide many soldiers and use their manpower to build the Mongol navy. The first attack was launched from Happo (Masan) on the southern coast of Korea.

The fleet of 900 ships carrying 40,000 soldiers sailed to Tsushima and then onto Kyushu, where they fought the Japanese in Hakata Bay. The second invasion force, also including many Koreans, involved two fleets, one of which left from Korea—a total of 4,400 ships and 142,000 soldiers.

Tens of thousands of Koreans were killed by the Japanese during these futile attacks or died when the ships in both attacks were hit by freak typhoons With so many of the soldiers having been Korean levies, the loss struck a major blow against the Korean economy and on the Koryo dynasty, which had, in name, supported the attack.

Many of the later rulers of the Koryo dynasty were young, with six of the last nine being teenagers or younger when they became king. King Chunghye (r. 1330–32, 1339–44), and King U (r. 1374–88) spent most of their reigns chasing wild animals in hunts, being involved in drunken parties, or having affairs with countless women.

King Kongmin (r. 1351–74) was the only one of the latter Koryo kings who provided any stability to the country. However after the death of his wife, he spent much of his reign obsessed with finding an auspicious place for her to be buried, and where he could also be interred.

He eventually settled on a spot about nine miles west of Kaesong where, on a steep hill, he built two matching burial mounds, one for himself, and the other for his wife. It is said that several astrologers were killed for displeasing Kongmin in his search for an auspicious site, including those who actually found the chosen location—slain in error by royal guards after Kongmin spent so long on the mountainside that they thought he had once again been taken to a location he did not like. The tombs of Kongmin and his wife were pillaged by the Japanese during their invasion of Korea in 1592 but have since been restored.

Although the Mongols dominated the kingdom of Koryo, when their power in China declined, it was a nervous time for the Koryo rulers. In 1382 the Chinese Ming dynasty started and the remnants of the Mongols and the other tribes that had supported them fled north, with some making their way to Manchuria with Ming armies following them.

In equipping an army to hold off any moves across the Korean border, the Koryo rulers put a large armed force under the command of General Yi Song-gye. Rather than securing the border, Yi Song-gye moved on Kaesong and seized the kingdom for himself, ushering in the Yi dynasty.