Founding and
Later Baekje , 951 In the late 7th century, the kingdom of
Silla unified the
Three Kingdoms of Korea and entered a period known in historiography as "
Unified Silla" or "Later Silla". Later Silla implemented a national policy of integrating
Baekje and
Goguryeo refugees called the "Unification of the
Samhan", referring to the Three Kingdoms of Korea. Silla organized a new central army called the
Ku-sŏdang () that was divided into 3 units of Silla people, 3 units of Goguryeo people, 2 units of Baekje people, and 1 unit of Mohe people. However, the Baekje and Goguryeo refugees retained their respective
collective consciousnesses and maintained a deep-seated resentment and hostility toward Silla. Later Silla was initially a period of peace, without a single foreign invasion for 200 years, and commerce, as it engaged in international trade from as distant as the Middle East and maintained maritime leadership in East Asia. Beginning in the late 8th century, Later Silla was undermined by instability because of political turbulence in the capital and class rigidity in the
bone-rank system, leading to the weakening of the central government and the rise of the "hojok" () regional lords. The military officer
Kyŏn Hwŏn revived Baekje in 892 with the descendants of the Baekje refugees, and the Buddhist monk
Kung Ye revived Goguryeo in 901 with the descendants of the Goguryeo refugees; these states are called
Later Baekje and
Later Goguryeo in historiography, and together with Later Silla form the
Later Three Kingdoms. Later Goguryeo originated in the northern regions of Later Silla, which, along with its capital located in modern-day
Kaesong, North Korea, were the strongholds of the Goguryeo refugees. Among the Goguryeo refugees was
Wang Kŏn, a member of a prominent maritime
hojok based in Kaesong, who traced his ancestry to a great clan of Goguryeo. Wang Kŏn entered military service under Kung Ye at the age of 19 in 896, before Later Goguryeo had been established, and over the years accumulated a series of victories over Later Baekje and gained the public's confidence. In particular, using his maritime abilities, he persistently attacked the coast of Later Baekje and occupied key points, including modern-day
Naju. Kung Ye was unstable and cruel: he moved the capital to
Cheorwon in 905, changed the name of his kingdom to Majin in 904 then Taebong in 911, changed his
era name multiple times, proclaimed himself the
Maitreya Buddha, claimed to read minds, and executed numerous subordinates and family members out of paranoia. In 918, Kung Ye was deposed by his own generals, and Wang Kŏn was raised to the throne. Wang Kŏn, who would posthumously be known by his
temple name of Taejo or "Grand Progenitor", changed the name of his kingdom back to "Goryeo", adopted the era name of "Heaven's Mandate", and moved the capital back to his home of Kaesong. Goryeo regarded itself as the successor to Goguryeo and laid claim to
Manchuria as its rightful legacy. One of Taejo's first decrees was to repopulate and defend the ancient Goguryeo capital of
Pyongyang, which had been in ruins for a long time; afterward, he renamed it the "Western Capital", and before he died, he placed great importance on it in his
Ten Injunctions to his descendants.
Unification In contrast to Kung Ye, who had harbored vengeful animosity toward Silla, Taejo (Wang Kŏn) was magnanimous toward the weakened kingdom. In 927, Kyŏn Hwŏn, who had vowed to avenge the
last king of Baekje when he founded Later Baekje, sacked the capital of Later Silla, forced the king to commit suicide, and installed a puppet on the throne. Taejo came to Later Silla's aid but suffered a major defeat at the hand of Kyŏn Hwŏn near modern-day
Daegu; Taejo barely escaped with his life thanks to the self-sacrifices of Generals
Sin Sung-gyŏm and Kim Nak, and, thereafter, Later Baekje became the dominant military power of the Later Three Kingdoms. However, the balance of power shifted toward Goryeo with victories over Later Baekje in 930 and 934, and the peaceful annexation of Later Silla in 935. Taejo graciously accepted the capitulation of the last king of Silla and incorporated the ruling class of Later Silla. In 935, Kyŏn Hwŏn was removed from his throne by his
eldest son over a succession dispute and imprisoned at the temple
Geumsansa, but he escaped to Goryeo three months later and was deferentially received by his former archrival. In 936, upon Kyŏn Hwŏn's request, Taejo and Kyŏn Hwŏn conquered Later Baekje with an army of 87,500 soldiers, bringing an end to the Later Three Kingdoms period. Goryeo proceeded to incorporate a major portion of the Balhae people whose links to Goguryeo were shared with Goryeo, accepting most of their royalty and nobility in their fold. Following the destruction of
Balhae by the
Khitan Liao dynasty in 927, the last crown prince of Balhae and much of the ruling class sought refuge in Goryeo, where they were warmly welcomed and given land by Taejo. In addition, Taejo included the Balhae crown prince in the Goryeo royal family, unifying the two successor states of Goguryeo and, according to Korean historians, achieving a "true national unification" of Korea. According to the
Goryeosa jeolyo, the Balhae refugees who accompanied the crown prince numbered in the tens of thousands of households. As descendants of Goguryeo, the Balhae people and the Goryeo dynasts were related. Taejo felt a strong familial kinship with Balhae, calling it his "relative country" and "married country", and protected the Balhae refugees. This was in stark contrast to Later Silla, which had endured a hostile relationship with Balhae. Taejo displayed strong animosity toward the Khitans who had destroyed Balhae. The Liao dynasty sent 30 envoys with 50 camels as a gift in 942, but Taejo exiled the envoys to an island and starved the camels under a bridge, in what is known as the "Manbu Bridge Incident". Taejo proposed to
Gaozu of
Later Jin that they attack the Khitans in retribution for Balhae, according to the
Zizhi Tongjian. Due to this constant massive influx of Balhae refugees, the Goguryeoic population in Goryeo is speculated to have become dominant in proportion compared to their Silla and Baekje counterparts that have experienced devastating war and political strife since the advent of the Later Three Kingdoms. By the end of the Later Three Kingdoms, territories populated by the original Silla people and considered that of "Silla proper" () were reduced to Gyeongju and bits of the vicinity. Later Baekje fared only little better than Later Silla before its fall in 936. Meanwhile, of the three capitals of Goryeo, two were Kaesong and Pyongyang which were initially populated by Goguryeoic settlers from the P'aesŏ Region () and Balhae. Nonetheless, Goryeo proceeded to peacefully absorbing the ruling class of both countries and incorporated them under its bureaucracy; conducting political marriages and distributing positions according to their previous status in their respective countries. In contrast to Silla's bone-rank system, these open policies implemented by Wang Kŏn enabled Goryeo to enjoy a larger pool of highly skilled bureaucrats and technicians with the addition of those coming from Silla and Baekje; later on instilling a single agenda in terms of identity amongst its people. During the time of its existence, Goryeo also accepted a large amount of skilled workers from Medieval China and
Tamna as well.
Political reformation , 10th century Although Goryeo had unified the
Korean Peninsula, the
hojok regional lords remained quasi-independent within their walled domains and posed a threat to the monarchy. To secure political alliances, Taejo married 29 women from prominent
hojok families, siring 25 sons and 9 daughters. His fourth son,
Gwangjong, came to power in 949 to become the fourth ruler of Goryeo and instituted reforms to consolidate monarchical authority. In 956, Gwangjong freed the prisoners of war and refugees who had been enslaved by the
hojok during the tumultuous Later Three Kingdoms period, in effect decreasing the power and influence of the regional nobility and increasing the population liable for taxation by the central government. In 958, advised by Shuang Ji, a naturalized Chinese official from the
Later Zhou dynasty, Gwangjong implemented the
kwagŏ civil service examinations, based primarily on the
imperial examination of the
Tang dynasty. This, too, was to consolidate monarchical authority. The
kwagŏ remained an important institution in Korea until its abolition in 1894. In contrast to Goryeo's traditional "dual royal/imperial structure under which the ruler was at once king, emperor and Son of Heaven", according to Remco E. Breuker, Gwangjong used a "full-blown imperial system". All those who opposed or resisted his reforms were summarily purged. Gwangjong's successor,
Gyeongjong, instituted the "Stipend Land Law" in 976 to support the new central government bureaucracy established on the foundation of Gwangjong's reforms. The next ruler,
Seongjong, secured centralization of government and laid the foundation for a centralized political order. Seongjong filled the bureaucracy with new bureaucrats, who as products of the
gwageo civil service examinations were educated to be loyal to the state, and dispatched centrally-appointed officials to administrate the provinces. As a result, the monarch controlled much of the decision making, and his signature was required to implement important decisions. Seongjong supported Confucianism and, upon a proposal by the Confucian scholar
Ch'oe Sŭng-no, the separation of government and religion. In addition, Seongjong laid the foundation for Goryeo's educational system: he founded the
Kukchagam national university in 992, supplementing the schools already established in Kaesong and Pyongyang by Taejo, and national libraries and archives in Kaesong and Pyongyang that contained tens of thousands of books.
Goryeo–Khitan War (blue), a wall built by Goryeo in the aftermath of the
Goryeo-Khitan War '' was begun in 1011 during the Khitan invasions to draw strength from the Buddha in defense of the kingdom. Following the "Manbu Bridge Incident" of 942, Goryeo prepared itself for a conflict with the Khitan Empire:
Jeongjong established a military reserve force of 300,000 soldiers called the "Resplendent Army" in 947, and Gwangjong built fortresses north of the
Chongchon River, expanding toward the
Yalu River. However an attempt to control the Yalu River basin in 984 failed due to conflict with the Jurchens. Negotiations began between the Goryeo commander,
Sŏ Hŭi, and the Liao commander, Xiao Sunning. In conclusion, Goryeo entered a nominal tributary relationship with Liao, severing relations with
Song, and Liao recognized Goryeo sovereignty to the land east of the Yalu River. Goryeo was left free to deal with the Jurchens south of the Yalu and in 994–996, Sŏ Hŭi led an army into the area and built forts. In 994, Goryeo proposed to Song a joint military attack on Liao, but was declined; previously, in 985, when Song had proposed a joint military attack on Liao, Goryeo had declined. For a time, Goryeo and Liao enjoyed an amicable relationship. with a promise that he would pay homage in person to the Liao emperor. The Khitans, who were sustaining attacks from previously surrendered districts and the regrouped Korean army which disrupted their supply lines, accepted and began their withdrawal. According to the
Goryeosa, due to continued attacks and heavy rain, the Khitan army was devastated and lost its weapons crossing the Yalu. They were attacked while crossing the Yalu River and many drowned. Afterward, Hyeonjong did not fulfill his promise to pay homage in person to the Liao emperor, and when demanded to cede the Six Garrison Settlements, he refused. The Liao army pushed on toward Kaesong under constant enemy harassment. After arriving within the vicinity of the well-defended capital, a contingent of 300 cavalry sent as scouts was annihilated, upon which the Liao army decided to withdraw. Beginning in 1034, merchants from Song and envoys from various Jurchen tribes and the
Tamna kingdom attended the annual
Palgwanhoe in Kaesong, the largest national celebration in Goryeo; During the reign of
Munjong, the
Heishui Mohe and Japan, among many others, attended as well. The Tamna kingdom of
Jeju Island was incorporated into Goryeo in 1105. Goryeo's golden age lasted about 100 years into the early 12th century and was a period of commercial, intellectual, and artistic achievement. The capital was a center of trade and industry, and its merchants developed one of the earliest systems of
double-entry bookkeeping in the world, called the ''sagae chi'bubŏp
, that was used until 1920. The Goryeosa
records the arrival of merchants from Arabia in 1024, 1025, and 1040, and hundreds of merchants from Song each year, beginning in the 1030s. There were developments in printing and publishing, spreading the knowledge of philosophy, literature, religion, and science. Goryeo prolifically published and imported books, and by the late 11th century, exported books to China; the Song dynasty transcribed thousands of Korean books. The first Tripitaka Koreana'', amounting to about 6,000 volumes, was completed in 1087. The () was established in 1055 by
Ch'oe Ch'ung, who is known as the "
Haedong Confucius", and soon afterward there were 12 private academies in Goryeo that rivaled the
Kukchagam national university. In response, several Goryeo rulers reformed and revitalized the national education system, producing prominent scholars such as
Kim Pusik. In 1101, the
Seojeokpo printing bureau was established at the
Kukchagam. In the early 12th century, local schools called were established. Goryeo's reverence for learning is attested to in the , or , a book by an envoy from the Song dynasty who visited Goryeo in 1123. In addition, he achieved the epitome of cultural blossoming in Goryeo. Munjong had 13 sons: the three eldest succeeded him on the throne, and the fourth was the prominent Buddhist monk
Uicheon. Goryeo was a period of great achievements in Korean art and culture, such as
Koryŏ celadon, which was highly praised in the Song dynasty, and the
Tripitaka Koreana, which was described by
UNESCO as "one of the most important and most complete corpus of Buddhist doctrinal texts in the world", with the original 81,258 engraved printing blocks still preserved at the temple
Haeinsa. In the early 13th century, Goryeo developed
movable type made of metal to print books, 200 years before
Johannes Gutenberg in Europe.
Goryeo-Jurchen War The Jurchens in the
Yalu River region were tributaries of Goryeo since the reign of
Taejo of Goryeo (r. 918–943), who called upon them during the wars of the
Later Three Kingdoms period. Taejo relied heavily on a large Jurchen cavalry force to defeat
Later Baekje. The Jurchens switched allegiances between Liao and Goryeo multiple times depending on which they deemed the most appropriate. The Liao and Goryeo competed to gain the allegiance of Jurchen settlers who effectively controlled much of the border area beyond Goryeo and Liao fortifications. These Jurchens offered tribute but expected to be rewarded richly by the Goryeo court in return. However the Jurchens who offered tribute were often the same ones who raided Goryeo's borders. In one instance, the Goryeo court discovered that a Jurchen leader who had brought tribute had been behind the recent raids on their territory. The frontier was largely outside of direct control and lavish gifts were doled out as a means of controlling the Jurchens. Sometimes Jurchens submitted to Goryeo and were given citizenship. Goryeo inhabitants were forbidden from trading with Jurchens. The tributary relations between Jurchens and Goryeo began to change under the reign of Jurchen leader
Wuyashu (r. 1103–1113) of the
Wanyan clan. The Wanyan clan was intimately aware of the Jurchens who had submitted to Goryeo and used their power to break the clans' allegiance to Goryeo, unifying the Jurchens. The resulting conflict between the two powers led to Goryeo's withdrawal from Jurchen territory and acknowledgment of Jurchen control over the contested region. As the geopolitical situation shifted, Goryeo unleashed a series of military campaigns in the early 12th century to regain control of its borderlands. Goryeo had already been in conflict with the Jurchens before. In 984, Goryeo failed to control the Yalu River basin due to conflict with the Jurchens. In 1080,
Munjong of Goryeo led a force of 30,000 to conquer ten villages. However by the rise of the Wanyan clan, the quality of Goryeo's army had degraded and it mostly consisted of infantry. There were several clashes with the Jurchens, usually resulting in Jurchen victory with their mounted cavalrymen. In 1104, the Wanyan Jurchens reached
Chongju while pursuing tribes resisting them. Goryeo sent Im Kan () to confront the Jurchens, but his untrained army was defeated, and the Jurchens took Chongju castle. Im Kan was dismissed from office and reinstated, dying as a civil servant in 1112. The war effort was taken up by
Yun Kwan, but the situation was unfavorable and he returned after making peace. Yun Kwan believed that the loss was due to their inferior cavalry and proposed to the king that an elite force known as the
Byeolmuban ("Special Warfare Army") be created. It existed apart from the main army and was made up of cavalry, infantry, and a
Hangmagun ("Subdue Demon Corps"). In December 1107, Yun Kwan and O Yŏnch'ong set out with 170,000 soldiers to conquer the Jurchens. The army won against the Jurchens and built Nine Fortresses over a wide area on the frontier encompassing Jurchen tribal lands, and erected a monument to mark the boundary. However due to unceasing Jurchen attacks, diplomatic appeals, and court intrigue, the Nine Fortresses were handed back to the Jurchens. In 1108, Yun Kwan was removed from office and the Nine Fortresses were turned over to the Wanyan clan. It is plausible that the Jurchens and Goryeo had some sort of implicit understanding where the Jurchens would cease their attacks while Goryeo took advantage of the conflict between the Jurchens and Khitans to gain territory. According to Breuker, Goryeo never really had control of the region occupied by the Nine Fortresses in the first place and maintaining hegemony would have meant a prolonged conflict with militarily superior Jurchen troops that would prove very costly. The Nine Fortresses were exchanged for Poju (
Uiju), a region the Jurchens later contested when Goryeo hesitated to recognize them as their suzerain. Later, Wuyashu's younger brother
Aguda founded the
Jin dynasty (1115–1234). When the Jin was founded, the Jurchens called Goryeo their "parent country" or "father and mother" country. This was because it had traditionally been part of their system of tributary relations, its rhetoric, advanced culture, as well as the idea that it was "bastard offspring of Koryŏ". The Jin also believed that they shared a common ancestry with the
Balhae people in the
Liao dynasty. The Jin went on to conquer the Liao dynasty in 1125 and capture the Song capital of
Kaifeng in 1127 (
Jingkang incident). The Jin also put pressure on Goryeo and demanded that Goryeo become their subject. While many in Goryeo were against this,
Yi Chagyŏm was in power at the time and judged peaceful relations with the Jin to be beneficial to his own political power. He accepted the Jin demands and in 1126, the king of Goryeo declared himself a Jin vassal (tributary). However the Goryeo king retained his position as "Son of Heaven" within Goryeo. By incorporating Jurchen history into that of Goryeo and emphasizing the Jin emperors as bastard offspring of Goryeo, and placing the Jin within the template of a "northern dynasty", the imposition of Jin suzerainty became more acceptable.
Power struggles The
Inju Yi clan married women to the kings from the time of Munjong to the 17th King,
Injong. Eventually the Inju Yi clan gained more power than the monarch himself. This led to the coup of Yi Chagyŏm in 1126. It failed, but the power of the monarch was weakened; Goryeo underwent a civil war among the nobility. In 1135,
Myoch'ŏng argued in favor of moving the capital to Sŏgyeong (now
Pyongyang). This proposal divided the nobles. One faction, led by Myoch'ŏng, believed in moving the capital to Pyongyang and expanding into
Manchuria. The other one, led by
Kim Pusik (author of the
Samguk sagi), wanted to keep the status quo. Myoch'ŏng failed to persuade the king; he rebelled and established the state of Taewi, but it failed and he was killed.
King Uijong went into exile and
King Myeongjong was placed on the throne. Effective power, however, lay with a succession of generals who used an elite guard unit known as the
Tobang to control the throne: military rule of Goryeo had begun. In 1179, the young general
Kyŏng Taesŭng rose to power and began an attempt to restore the full power of the monarch and purge the corruption of the state. However, he died in 1183 and was succeeded by
Yi Ŭimin, who came from a
nobi (slave) background. During this period, despite nearly three centuries of Goryeo rule, loyalty to the old Silla kingdom and Silla traditions remained latent in the Kyŏngju area. There were multiple rebellions by the
Silla restoration movement to overthrow Goryeo's rule over the Sillan people. Yi's unrestrained corruption and cruelty Ch'oe Ch'unghŏn was succeeded in turn by his son
Ch'oe U, his grandson
Ch'oe Hang and his great-grandson
Ch'oe Ŭi. When he took control, Ch'oe Ch'unghŏn forced Myeongjong off the throne and replaced him with
King Sinjong. What was different from former military leaders was the active involvement of scholars in Ch'oe's control, notably Prime Minister
Yi Kyu-bo who was a Confucian scholar-official. where the remaining Khitans were finished off by allied Mongol-Goryeo forces in 1219. Tension continued through the 12th century and into the 13th century, when the
Mongol invasions started. After nearly 30 years of warfare, Goryeo swore allegiance to the Mongols, with the direct dynastic rule of Goryeo monarchy. The royal court moved to Ganghwado in the Bay of Gyeonggi in 1232. The military ruler of the time,
Ch'oe U, insisted on fighting back. Goryeo resisted for about 30 years but finally sued for peace in 1259. Meanwhile, the Mongols began a campaign from 1231 to 1259 that ravaged parts of
Gyeongsang and
Jeolla. There were six major campaigns: 1231, 1232, 1235, 1238, 1247, 1253; between 1253 and 1258, the Mongols under
Möngke Khan's general Jalairtai Qorchi launched four devastating invasions against Korea at tremendous cost to civilian lives throughout the Korean Peninsula. Civilian resistance was strong, and the Imperial Court at Ganghwa attempted to strengthen its fortress. Korea won several victories but the Korean military could not withstand the waves of invasions. The repeated Mongol invasions caused havoc, loss of human lives and famine in Korea. In 1236, Gojong ordered the recreation of the
Tripitaka Koreana, which was destroyed during the 1232 invasion. This collection of Buddhist scriptures took 15 years to carve on some 81,000 wooden blocks, and is preserved to this day. In March 1258, the dictator
Ch'oe Ŭi was assassinated by
Kim Chun. Thus, dictatorship by his military group was ended, and the scholars who had insisted on peace with Mongolia gained power. Goryeo was never conquered by the Mongols, but exhausted after decades of fighting, Goryeo sent Crown Prince
Wonjong to the
Yuan capital to swear allegiance to the Mongols;
Kublai Khan accepted, and married one of his daughters to the Korean crown prince. Khubilai, who became khan of the Mongols and emperor of China in 1260, did not impose direct rule over most of Goryeo. Goryeo Korea, in contrast to Song China, was treated more like an Inner Asian power. The dynasty was allowed to survive, and intermarriage with Mongols was encouraged, even with the Mongol imperial family, while the marriage between Chinese and Mongols was strictly forbidden when the Song dynasty was ended. Some military officials who refused to surrender formed the
Sambyeolcho Rebellion and resisted in the islands off the southern shore of the Korean Peninsula.
Late period After 1270, Goryeo became a semi-autonomous
client state of the
Yuan dynasty. The Mongols and the Kingdom of Goryeo tied with marriages and Goryeo became
khuda (marriage alliance) vassal of the Yuan dynasty for about 80 years and monarchs of Goryeo were mainly imperial sons in-law (
khuregen). The two nations became intertwined for 80 years as all subsequent Korean kings married Mongol princesses, Empress Gi was sent to Yuan as one of the many
kongnyŏ (貢女; lit. 'tribute women', who were in effects slaves sent over as a sign of Goryeo submission to the Mongols) Empress Gi had great political influence both the Yuan and the Goryeo court, and even manage to significantly increase the status and influence of her family members, including her father who was formally made into a king in the Yuan and her brother
Ki Ch'ŏl who at some point manage to get more authority than the Goryeo king. It is claimed that one of Goryeo monarchs was the most beloved grandson of
Kublai Khan. The Goryeo dynasty survived under the Yuan until King
Gongmin began to push the Mongolian garrisons of the Yuan back in the 1350s. By 1356 Goryeo regained its lost northern territories.
Last reform When King Gongmin ascended to the throne, Goryeo was under the influence of the Mongol Yuan China. He was forced to spend many years at the Yuan court, being sent there in 1341 as a virtual prisoner before becoming king. He married the Mongol princess
Princess Noguk (also known as Queen Indeok). But in the mid-14th century the Yuan was beginning to crumble, soon to be replaced by the
Ming dynasty in 1368. King Gongmin began efforts to reform the Goryeo government and remove Mongolian influences. His first act was to remove all pro-Mongol aristocrats and military officers from their positions. Mongols had annexed the northern provinces of Goryeo after the invasions and incorporated them into their empire as the
Ssangseong and
Dongnyeong Prefectures. The Goryeo army retook these provinces partly thanks to defection from
Yi Chach'un, a minor Korean official in service of Mongols in Ssangseong, and his son
Yi Sŏnggye. In addition, Generals Yi Sŏnggye and Chi Yongsu () led a campaign into
Liaoyang. After the death of Gongmin's wife Noguk in 1365, he fell into depression. In the end, he became indifferent to politics and entrusted that great task to the Buddhist monk
Sin Ton. But after six years, Sin Ton lost his position. In 1374, Gongmin was killed by Hong Ryun (), Ch'oe Mansaeng (), and others. After his death, a high official Yi Inim assumed the helm of the government and enthroned eleven-year-old, King U, the son of King Gongmin. During this tumultuous period, Goryeo momentarily conquered
Liaoyang in 1356, repulsed two large
invasions by the Red Turbans in 1359 and 1360, and defeated the final attempt by the Yuan to dominate Goryeo when General
Ch'oe Yŏng defeated an invading Mongol
tumen in 1364. During the 1380s, Goryeo turned its attention to the
Wokou menace and used
naval artillery created by
Ch'oe Musŏn to annihilate hundreds of pirate ships.
Fall In 1388,
King U (son of
King Gongmin and a concubine) and general
Ch'oe Yŏng planned a campaign to invade now
Liaoning of China. King U put the general Yi Sŏnggye (later Taejo) in charge, but he stopped at the border and rebelled. Goryeo fell to Yi Sŏnggye, who put to death the last three Goryeo kings, usurped the throne, and established in 1392 the
Joseon dynasty. ==Government==