Goryeo under Mongol rule

Goryeo under Mongol rule refers to the rule of the Mongol Empire and the Mongol-led Yuan dynasty over the Korean Peninsula from about 1270 to 1356. After the Mongol invasions of Korea and the capitulation of the Korean Goryeo dynasty in the 13th century, Goryeo became a semi-autonomous vassal state and compulsory ally of the Yuan dynasty for about 80 years. It has been referred to as a "son-in-law kingdom in the Mongol Empire." The ruling line of Goryeo, the House of Wang, was permitted to rule Korea as a vassal of the Yuan, which established the Branch Secretariat for Eastern Campaigns (征東行省; literally "Branch Secretariat for Conquering the East") in Korea as an extension of Mongol supervision and political power. Members of the Goryeo royal family were taken to Khanbaliq, and typically married to spouses from the Yuan imperial clan, the House of Borjigin. As a result, princes who became monarchs of Goryeo during this period were effectively imperial sons in-law (khuregen). Yuan overlordship ended in the 1350s when the Yuan dynasty itself started to crumble and King Gongmin of Goryeo began to push the Yuan garrisons back.

Mongol invasions
The Mongol Empire launched several invasions against Korea under Goryeo from 1231 to 1259. 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 in the final successful campaign against Korea, at tremendous cost to civilian lives throughout the Korean Peninsula. The Mongols annexed the northern areas of Korean Peninsula after the invasions and incorporated them into their empire as Ssangseong Prefecture and Dongnyeong Prefecture.

In 1216, a host of Khitans fleeing the Mongols crossed into Goryeo. A Mongol detachment chased after them in 1219 and demanded an alliance with the Goryeo against the Khitans. Goryeo agreed and started paying tribute. In 1224, a Mongol envoy was killed under uncertain circumstances, resulting in the cessation of tribute from Goryeo. Ögedei Khan dispatched Sartaq against Goryeo and after they ravaged the Korean countryside, Goryeo accepted the placement of overseers known as darughachi within its borders. However Ch'oe U (r. 1219–1249) murdered all the darughachi and moved the court from Gaegyeong to the more defensible Ganghwa Island. Ch'oe was willing to send tribute but refused to accept overseers, send royal hostages, or return the court to Gaegyeong. Further campaigns against Goryeo by the Mongols were undertaken by Tanggud (1253–1254), Ebügen (1247–1248), Prince Yekü (1253–1254), and Jalairtai (1254–1255). Goryeo did not militarily confront the Mongols but retreated into the mountain fortresses and islands. In 1241, Goryeo sent Wang Sun (1224–1283), a distant relative of the royal family, as hostage to the Mongols. Devastation from the Mongol raids caused the peasants to defect to the Mongols, who established Ssangseong Prefecture with the aid of local officials.

In March 1258, Ch'oe Ui of the Goryeo military regime was assassinated by Kim Chun, ending Ch'oe family dominance and returning the king to power. The new government sent Wang Chŏn as hostage to the Mongol court and Kublai Khan sent him back after 1259 to assume government. Wang Chŏn was enthroned as Wonjong of Goryeo in June 1260. Wonjong's government led by Kim Chun was overthrown by Im Yŏn in 1269. In response, the Mongols backed the rebellion of another group of Goryeo officials in the northwest and created the Dongnyeong Prefecture. Another invasion was prepared in 1270. In an event known as the Sambyeolcho Rebellion, the Three Patrols army (sambyeolcho) that served Goryeo's government rebelled against the Im family, overthrew them, and moved the officials back to Gaegyeong from Ganghwa. They fled to Jindo Island and then Jeju Island, where they remained until 1273 when Goryeo forces arrived and defeated them, after which a part of the island was converted to a breeding ground for the Yuan royal herd. Goryeo regained formal control of Dongnyeong in 1290 and Jeju in 1294. However the military command (Tumen) on Jeju remained outside of their jurisdiction.

Due to the turmoil caused by the Mongol invasions, a number of Koreans from northern Goryeo entered China either as captives or willingly to seek their fortunes elsewhere, especially in the Yuan capitals of Khanbaliq and Shangdu. Looser control from the Goryeo government resulted in the departure of farming families for Liaoyang and Shenyang to escape tax and labor services. Possibly as many as 250,000 Koreans lived in China during this period.

Mongol invasions of Japan
Militarily, following the 1259 peace treaty, Mongol ambitions on Japan resulted in two invasions of Japan. In both efforts, the Mongols directed Korean shipbuilding and militarization towards the amphibious assault of the Japanese coasts and pressed a large proportion of Korean naval and infantry forces into the service of Mongol military objectives. Korea supplied 770 fully manned ships and 5,000 soldiers in 1274 and 900 ships and 10,000 soldiers in 1281. Yuan officials and envoys took concubines and wives in Korea while they were stationed in Korea for the invasion of Japan. For a variety of reasons, both invasions failed. During the periods leading up to and during the invasions, Korea was effectively forced to serve as a Mongol military base. The Yuan dynasty paid for ships and soldiers in Goryeo with baochao paper money.



Status
After 1270, Goryeo became a "fully integrated client kingdom," however official protocol was that of a subordinate principality. David M. Robinson described Goryeo's status as incorporated within the "Great Yuan ulus" but legally distinct from the rest of the empire. Yuan legal codes separated Goryeo from southern China. Rashid al-Din Hamadani described Goryeo as a province in name but a separate state within the Yuan dynasty. It has also been called a "son-in-law kingdom in the Mongol empire" because starting with King Chungnyeol (r. 1274-1308), kings of Goryeo were married to Mongol Borjigid princesses and Goryeo princes were raised and educated at the Yuan court. Gongmin of Goryeo (r. 1351-1374) referred to Goryeo's relationship with the Genghisids as that between vassal and lord. Because of royal marriages with princesses of the Mongol Yuan royal family, Goryeo was considered unique among the states.

In 1280, the Branch Secretariat for Eastern Campaigns was created, which lasted until the end of the dynasty. According to Christopher P. Atwood, the Goryeo prince served as the grand councilor (chengxiang) but the secretariat managers (pingzhang) were appointed by the Yuan court. In 1300, Manager Körgüz proposed abolishing Goryeo court ritual and official hierarchy to better fit its status as a province, but this proposal was rejected. The Mongols established several autonomous commands in Korea that remained outside the control of the Goryeo court. However George Qingzhi Zhao states that the kings of Goryeo retained the autonomy to conduct their own government, including setting up bureaucratic structures, selecting officials, exercising laws and taxes, and using those taxes for Goryeo rather than sending them to the Yuan court.

The issue of Goryeo's status was raised again in 1302 and between 1309-1312. In both cases, the proposal to change Goryeo's status was raised by the Hong clan of Hong Ta-gu, who were Goryeo defectors with a long history of conflict with their homeland. The Hong clan was a warlord family that originated in northwestern Goryeo. They made contact with the Mongols in 1218 and defected to the Mongol Empire in 1231. As a former warlord family in Goryeo, the Hong clan specialized in military matters pertaining to Goryeo and made their name by participating in campaigns against their homeland, even stoking conflict on purpose to their benefit. In 1302, they proposed combining Liaoyang and the Branch Secretariat for Eastern Campaigns (Goryeo). Between 1309-1312, the sons of Hong Ta-gu proposed establishing a province in Goryeo instead of having a separate kingdom. This was because Chungseon of Goryeo held both the position of king of Goryeo and Wang of Shenyang. The Wang of Shenyang was created in 1260 to rule Goryeo people living in Shenyang. While real power resided in the Hong clan and other families, the symbolic power of the post occupied by the Goryeo royal family provided an alternative center of power among the Goryeo elites. In 1308, Külüg Khan granted the post to Chungseon. The emperor rejected the proposal to turn Goryeo into a province in 1312. The Hong clan lost most of its power and the brothers are not mentioned again after 1312.

Goryeo was lower ranked than Inner Asians who surrendered to the Mongols earlier. When the Mongols placed the Uighurs of the Kingdom of Qocho over the Koreans at the court the Korean King objected. The Mongol Emperor Kublai Khan said that the Uighur king of Qocho was ranked higher than the Karluk Kara-Khanid ruler, who in turn was ranked higher than the Korean King, who was ranked last among the three because the Uighurs surrendered to the Mongols first, the Karluks surrendered after the Uighurs, and the Koreans surrendered last, and that the Uighurs surrendered peacefully without violently resisting. Koreans were classified along with Northern Chinese, Khitan, Balhae and Jurchen people as "Han people."

Branch Secretariat for Eastern Campaigns
The Branch Secretariat for Eastern Campaigns was created in 1280 to mobilize Goryeo resources for the Mongol invasions of Japan. Its offices were located in Gaegyong and was nominally led by the king of Goryeo, who held the dual titles of Imperial Son-in-Law King of Goryeo and Minister of the Left of the Branch Secretariat for Eastern Campaigns. However even though it was largely staffed by Goryeo officials, it was directly subordinate to the Yuan throne, which stationed Chinese, Jurchens, and Mongols in many of the Branch Secretariat's key posts. After the end of the Japanese campaigns, the Branch Secretariat continued to function as an institution of Mongol political control in Goryeo, with King Chungnyeol of Goryeo being appointed as its head by Kublai Khan in 1288 with the expectation that he would contribute to the Mongol Civil War. To gain Kublai's acceptance and prevent further demands, Chungnyeol dressed in Mongol clothing, cut his hair in the Mongol fashion, and agreed to change the names of Goryeo's administrative bureaus to reflect their subordination to the Mongols. Chungnyeol's successor, Chungseon of Goryeo (Kublai's grandson), spent a good deal of his youth in the Yuan capital and saw himself as both the king of Goryeo and as a prince of the empire. He favored adopting the Yuan legal code and implementing reforms to reduce Goryeo's slave population, which elicited opposition from Goryeo elites who feared that such measures would erode Goryeo's sovereignty. They appealed to Kublai's order that Goryeo's "dynastic customs" be retained and argued that aligning with Yuan legal institutions contravened Kublai's will. As a result of such advocacy, fundamental changes to Goryeo's institutions were not made. Chungseon abdicated in 1313 after only five years on the throne and chose to live in the Yuan capital instead because he believed the Yuan court was the true center of power, and power in Goryeo ultimately came from successfully cultivating relations there.

In 1343, King Chunghye of Goryeo was dethroned after being arrested by Yuan envoys. Gi Cheol and Hong Bin were appointed to the Branch Secretariat's leadership by the Yuan until Chunghye's son, Wang Heun, had an audience with the Yuan emperor Toghon Temür, and was appointed king as well as head of the Branch Secretariat.

The darughachi were Mongolian resident commissioners sent to the Goryeo court. These commissioners, while nominally subordinate to the Goryeo king, were routinely supplied with provisions and were actively involved in the affairs of the Goryeo court.

Although the Branch Secretariat was used as a means of Mongol political control over Goryeo, Goryeo rulers also used the Branch Secretariat to advance their own claims on the Goryeo throne. The king's position as head of the Branch Secretariat enhanced his station within Goryeo as well as in the empire. Chungsuk of Goryeo lobbied Mongols, Koreans, and Chinese with ties to the Yuan court for support in regaining his throne from his son and promised them posts in the Branch Secretariat. Chungseon also benefited from three rest stop villages established by Kublai in 1279 between Goryeo and Khanbaliq that became his base for expansion into Liaoyang. He was granted lands on the northern bank of the Yalu and gained significant influence over the region.

The Branch Secretariat was responsible for administering imperial exams. Twenty-three Goryeo men passed the Yuan provincial examination at the Branch Secretariat between 1315 and 1353.

Marriage
Once the treaty was concluded and vassaldom established, intermarriage between the Koreans and Mongols was encouraged by the Mongol Empire. After the death of Wonjong in 1274, his successor Chungnyeol of Goryeo received Kublai's daughter Qutlugh-Kelmish as a wife, and his reign began a wholesale Mongolization of the Korean court that continued until the middle of the 14th century. On paper, the official protocol for Korea was that of a subordinate principality, and Korean rulers made lengthy stays at the Mongol Yuan court, both before and after their coronation. In addition, their Mongol wives, and even concubines, exerted great influence over Goryeo politics. For instance, Bayankhutag, Princess Gyeonghwa selected officials for posts within the Goryeo government. The Mongols and the Kingdom of Goryeo became linked via marriage and Goryeo became a quda (marriage alliance) state of the Yuan dynasty; monarchs of Goryeo during this period were effectively imperial sons in-law (khuregen). The effects of intermarriage on Mongol-Goryeo relations worked both ways: during the reign of Kublai Khan, King Chungnyeol of Goryeo married one of Kublai's daughters; later, a court lady from Korea called the Empress Gi became an empress through her marriage with Ukhaantu Khan, and her son, Biligtü Khan of the Northern Yuan dynasty, became a Mongol Khan. Furthermore, the kings of Goryeo held an important status within the Mongol imperial hierarchy, much like other important families of conquered or client states of the Mongol Empire (e.g. the Uyghurs, the Oirats, and Khongirad). Beginning with the marriage of Chungnyeol and Khudulugh Khaimish, a daughter of Kublai Khan, a total of nine princesses of the Yuan court married into the Goryeo royal family.



Korean women first entered the Mongol Empire as war booty. Later in the 13th century, Kublai and the Mongol elites started demanding women from elite Goryeo families as wives and consorts. Goryeo refused these demands but created an official government bureau in Goryeo for the organization of and flow of tribute women to the Mongol Empire. The Mongols also extracted other tributes such as gold, silver, cloth, grain, ginseng, and falcons from Goryeo. As with all parts of the Mongol Empire, Goryeo provided palace women, eunuchs, Buddhist monks, and other personnel to the Mongols.

Yuan envoys regularly visited Goryeo to procure women in the name of the emperor, who distributed them to leading ministers on many occasions. Almost 1,500 Korean women were noted as tribute in Yuan and Goryeo documents but the number was likely greater if including personal maids and servants who accompanied the women and others who were undocumented. One concubine who entered the Yuan court, Empress Gi, was instrumental in the popularization of Korean clothing, food, and lifestyle in the capital through her political command and incorporation of Korean females and eunuchs in the court. It became prestigious to marry Korean women among members of the Yuan elite. A native of Qingyuan named Nasen traveled to Khanbaliq in 1355 and wrote a poem comparing the poor existence of Chinese villagers to the life of luxury a Korean woman experienced in the capital.

Aftermath
The Goryeo dynasty survived under the Yuan until King Gongmin began to push the Mongolian garrisons of the Yuan back in the 1350s, when the Yuan dynasty faced the Red Turban Rebellion in China. Empress Gi and her eunuch Bak Bulhwa attempted a major coup of Northern China and Koryo. Goryeo incurred negative consequences as a result of the eunuch Bak Bulhwa's actions. Empress Gi intervened in Goryeo and her family contended with the Goryeo royal family; her family was purged by Gongmin of Goryeo in 1356. By 1356 Goryeo under King Gongmin regained its lost northern territories such as the Ssangseong Prefecture placed under the Liaoyang province by the Yuan. He also repulsed the Red Turban invasions of Goryeo in 1360. Empress Gi sent the Mongol army to invade Goryeo in 1364, but it failed. However, even after the eventual expulsion of the Yuan dynasty from China in 1368, some Goryeo kings such as U still favored the Yuan, still a formidable power in the Mongolian Plateau as the Northern Yuan, over the Ming dynasty established by Han people. This changed with the overthrow of Goryeo in 1392 by Yi Seong-gye, founder of Joseon, who cut off relations with the Mongols.

Military
Under Mongol rule, the northern defenses of Goryeo were reduced and the standing army was abolished. In their place, Goryeo relied on mobilizing men from the general populace on an ad hoc basis depending on military circumstances, while the Yuan-controlled Ssangseong Prefecture and Yuan forces north of the Yalu River became the true defense of Goryeo's northern border. The Palace Guard (Sukwigun) became known less for its martial prowess and more for its numerous profitable posts. By the mid-14th century, the Goryeo king's personal guards were modeled after the Mongol Kheshig with some prestigious posts given Mongol titles.

The Mongol military system known as the tumen, or myriarchy, based on units of 10,000 was introduced to Goryeo. The numerical strength of 10,000 was often nominal in nature and failed to reach that number. They were filled by Goryeo soldiers and led by Goryeo officers, representing a degree of autonomy from the Mongols. However the appointment of officers was effectively controlled by the Mongols throughout the mid-14th century and they reserved the right to call on Goryeo's military forces for their own campaigns.

When Chunghye was arrested by Yuan envoys in 1343, two Goryeo military commanders aided the Yuan in delivering the king to the Yuan court. Following the arrest, a number of Goryeo officers raided the homes of several powerful families, but it is uncertain whether this was opportunistic exploitation of the situation or if it was done on the emperor's orders.

Culture
Mongol domination in both political and military life led to the adoption of Mongol cultural customs throughout Northeast Asia. Mongolian style clothing and hairstyles were well received among much of Goryeo's court. The Mongolian diet is also said to have had a deep impact on Korean cuisine. Mongol names, which were bestowed by the Yuan court for contributions rendered to the empire, began appearing in the Chinese and Korean populations. Korean culture such as clothing also became popular among the elites of Khanbaliq during the 13th and early 14th centuries through the import of Korean women. Probably as a result of imperial patronage and its associated prestige, Korean fashions spread into the Jiangnan region, and even some degree of Korean language competence was heard of among the guards.

Scholars from Goryeo traveled in China and to Khanbaliq, where they encountered strains of Neo-Confucian thought, which they took with them back to Goryeo. In 1314, Ayurbarwada Buyantu Khan donated 17,000 juan from the former Southern Song archives to Goryeo. In Khanbaliq and the Jiangnan region, Korean scholars studied Zhu Xi and prepared for the Yuan imperial examinations, while Chinese administrators assigned to Goryeo disseminated Neo-Confucian ideology as well.

Economy
Yuan paper currency entered Goryeo's markets as gifts and payments for goods and services rendered. As a result, Yuan inflationary pressure also affected Goryeo through the royal family and the government elite with ties to Khanbaliq. The Goryeo royal family maintained several residences in the Yuan capital where they incurred expenses and took loans from merchants.

Sea routes connected Goryeo to Khanbaliq through the port of Zhigu in Shandong. In 1295, a Goryeo official sent 14,000 bolts of linen to Shandong, where the goods were transported to via land to Yidu. They were then exchanged for paper currency there for use by the heir apparent of Goryeo in Khanbaliq.