Genko (Mongol invasion) (元寇)

Genko is the Japanese name of two invasions (expeditions) that Japan suffered in the middle Kamakura period from the Mongol Empire (Yuan Dynasty), which was then dominant on the continent, and its subjected kingdom, the Kingdom of Goryeo. The first invasion is called Bunei no Eki (the Bunei War, 1274) and the second is called Koan no Eki (the Koan War, 1281). It is also referred to as Moko Shurai.


Years referred to in () are according to the Julian calendar, while all months and days, excluding years mentioned in the Western calendar, are according to the Japanese calendar calculated in a later era in accordance with the Senmyo calendar (Chinese luni-solar calendar employed in Japan).

From Diplomatic Negotiations to Invasion

Kublai, who in 1260 became the fifth emperor (Khan) of the Mongol Empire that was later called 'Yuan' (the Great Yuan Ulus, Great Yuan Dynasty or Yuan Dynasty), in 1266 planned to send the first envoys to establish diplomatic relations with Japan, through Goryeo in the Korean peninsula, which had already become its subject, while starting to conquer the Southern Sung Dynasty in 1268, which had been its long-standing aim since the reign of the second emperor Ogodei. According to "Genshi Nihon Den" (Japan in the History of the Yuan Dynasty), these envoys were going to be sent because of a proposal made by Cho-i who was from Goryeo and a government official of the Yuan Dynasty. However, the Mongol envoys (chief envoy Kokuteki and vice-envoy Inko), guided by So Kunhi and Kinsan from Goryeo, returned due to the difficulty of the voyage after reaching Geoje Island, and explained to Kublai that it was unnecessary to send envoys to Japan. Kublai had ordered them strictly to deliver the imperial letter to Japan and "not to give up for a reason attributable to bad weather," and thus, when both envoys returned without crossing the sea due to the reason of 'bad weather,' he got upset and did not accept it. He then ordered Goryeo again, and Hanpu, who was a secretary close to King Wonjong of Goryeo, was sent as envoy and reached Dazai-fu (local government office in the Kyushu region) in January 1268. Sukeyoshi SHONI (Sukeyoshi MUTO) of Dazai-fu received the letter from the Mongol Empire (letter and records according to Japanese materials) and the one from the king of Goryeo, and sent them to Kamakura bakufu (Japanese feudal government headed by a shogun) (however, Hanpu returned to Goryeo seven months after his arrival at Dazai-fu, possibly because Japan showed no intention to reply, and in October of the same year, Goryeo reported to the Yuan imperial court, by envoy Hanpu himself visiting there, that he had gained no fruit).

In Kamakura bakufu, after the death of the fifth regent Tokiyori HOJO, whose heir Tokimune HOJO was too young, Nagatoki HOJO from a branch line became the sixth regent, who was succeeded by the seventh regent Masamura HOJO, and then Tokimune HOJO finally reached the age of manhood and supported Masamura as rensho (assistant to regents). However, facing this increasing threat, Tokimune assumed the position of the eighth regent in March 1268. Bakufu asked Saneuji SAIONJI, who was kanto moshitsugi (court-appointed liaison with bakufu), to deliver the letter from the Mongol Empire to the Imperial Court, and led the court to the decision to ignore it. Bakufu also purged Tokimune's older brother by a concubine, Tokisuke HOJO, and others, in order to strengthen its leadership through Nigatsu-sodo (February rebellion) just after the death of the retired Emperor Gosaga, and in addition, ordered various provinces to guard against foreign attacks and held prayer services for the surrender of foreign enemies. It also influenced people of religion, and Nichiren submitted "Rissho Ankoku Ron" (Treatise for Spreading Peace Throughout the Country by Establishing the True Teaching) to bakufu, insisting that it was a national crisis.

In the same year, vasslas from Goryeo were sent again, including chancellor Shin Shisen, assistant chancellor Chin Shiko and Hanpu, accompanying chief envoy Kokuteki and vice-envoy Inko, but Japan ignored these second envoys who reached there. However, these envoys did not reach as far as Dazai-fu, only Tsushima Island, where they had a dispute with local people and captured two men on the island called Tojiro and Yajiro, and brought them home. In response to it, Sambyeolcho, which had risen in a rebellion against Goryeo, sent envoys to Japan to ask for military support and cooperation to fight against the Yuan Dynasty, but it was also ignored.

In September 1271, when envoys from the Yuan Dynasty, including Chao Liang-pi, brought a letter ordering Japan to become its subject, bakufu submitted it to the Imperial Court. The Imperial Court hurriedly sent an envoy to Ise-jingu Shrine and held a prayer service for the surrender of foreign enemies. Although there was an argument in the Imperial Court over whether or not to reply, bakufu opposed replying, and the majority of the Imperial Court also had a strong attitude, insisting, 'we should not yield to the demand of the Yuan Dynasty,' and thus, both the Imperial Court and bakufu decided to ignore the letter. Kublai continued sending envoys to Japan several times after that, but Japan ignored all of them, and in the end, he decided on a military invasion.

According to "Genshi Korai Den" (Goryeo in the History of the Yuan Dynasty), there were three plans in the beginning.

Demanding Japan to become its subject by sovereign's message, keeping soldiers in Goryeo, because Japan is an island country and difficult to conquer. This plan could strengthen its governing power in Goryeo and isolate the Southern Sung Dynasty and Japan from each other, without suffering any damage.

Conquering the Southern Sung Dynasty first, and then Japan, employing the subjected people of Han. This plan would enable it to obtain a large number of soldiers and was supported by Mongol high officials.

Conquering Japan via the eastern route, by employing the Goryeo army. This plan might have a problem of a shortage of soldiers.

According to "Koraishi" (The History of Goryeo) and "Genshi" (The History of the Yuan Dynasty), Mongol high officials were worried about soldier shortage and insisted on conquering the Southern Sung Dynasty first, but Goryeo (later King Chungnyeol) persistently requested them to invade Japan from the eastern route via Goryeo, and thus it was so decided.

Kublai ordered Goryeo to construct ships to invade Japan, and supplied them with food. Goryeo bore the construction expenses and completed large and small ships, which are said to have been 900 in total, in a such short period of six months. Kamakura bakufu, which had noticed these activities, created the position of Ikoku Keigo Banyaku (Foreign Enemy Defense) in 1272, and ordered the Shoni clan (Muto clan) serving as Chinzei Bugyo (Defense Commissioner of the West) and the Otomo clan to supervise it. The Yuan Dynasty conquered Xiangyan in the Southern Sung Dynasty in February 1273, and also subdued Sambyeolcho.

Bunei no Eki

In November 1274, the ships departed from Gappo in the Korean peninsula (now Masan) with 30,000 people on board, including non-soldiers, led by Xin Dou, Kim Bang-gyeong and others, consisting of people of Mongol, Han, Jurchen, and Goryeo.

They attacked Tsushima on October 5 and Iki on October 14 (both dates according to old lunar calendar), completely destroying the headquarters of the Matsuura Party (group of local warriors based in Matsuura area) in Taka-shima Island, Hirado, and drove Shugodai (Deputy Military Governor) of Iki Province TAIRA no Kagetaka to committing suicide. In addition, according to "Shin Genshi" (New History of the Yuan Dynasty), a letter of Nichiren describes that they then massacred people and made a hole in the palms of survivors to lace a leather cord through it, and hung them on the ships' sides as a warning. According to Goryeo's records, a general from Goryeo then captured 200 children, including both boys and girls, and presented them to the king and queen.

The situation of Iki was informed to Hakata, and then urgent messages were dispatched to Kyoto and Kamakura. In Japan, gokenin (an immediate vassal of the shogunate in the Kamakura and Muromachi through Edo periods) were gathering in Dazai-fu, including the Shoni clan and Otomo clan, mainly those from Kyushu region.

The Yuan army appeared in Hakata Bay on October 19 (according to old lunar calendar), and anchored ships at Imazu, located at the western edge of the bay, to disembark some of its soldiers. On October 20 (according to old lunar calendar, on November 25 according to solar calendar), the fleet moved towards the east, disembarking at Momochihama, and then at Jigyohama, Nagahama, Nanotsu, Suzakihama (Hakata), Higashihama, and Hakozakihama. The soldiers having disembarked at the western part of Hakata Bay took a position at Sohara (now Mt. Sohara) and Beppu.

Japanese samurai, in the beginning, suffered damage unilaterally because they tried to fight one to one declaring their names, or led attacks in a small group, but around noon they organized themselves to fight with a large number of soldiers, and following the arrival of reinforcements, started to counterattack. According to "Hachiman Gudokun" (Tales of the God of War Told to the Simple) (one of so-called Koshu-type editions of "Hachiman Gudokun"), troops consisting of approximately 230 samurai on horseback, led by Takefusa KIKUCHI and others, defeated the Yuan army of about 2,000 foot soldiers, in Akasaka located three kilometers east of Momochihama. According to "Moko Shurai Ekotoba" (Picture Scroll of the Mongol Invasion), Suenaga TAKEZAKI chased the enemy from Torikaigata to Sohara, and forced it back to the place about 500 meters from where they had disembarked. He attacked further in front, without waiting for other units to arrive, and when he fell into danger, Michiyasu SHIRAISHI and others came to rescue him, and then an arrow battle started.

In Hakata, they had a fierce arrow battle near the coast, and the Japanese army lost and withdrew, but prevented the enemy from advancing inland, using the rearguard unit led by Kagesuke SHONI, shooting an arrow at LIU Fu-heng, who came in pursuit. According to "Koraishi," it soon became dark and the battle ended, and the Japanese army returned to Dazai-fu.

Meanwhile, the Yuan army occupied Hakata, but arrows ran short due to day-long fierce battles and the army became disorganized. It therefore gave up the conquest of Dazai-fu and decided to withdraw, leaving the city of Hakata on fire.

The records on Bang-gyeong KIM in "Koraishi" include descriptions that seem to be part of the military meeting held on that night after returning to their position, saying that the following conversation was held between the head of the Goryeo army Bang-gyeong KIM and commander-in-chief of the expeditionary force Dou XIN.

Bang-gyeong KIM said, "an art of war teaches us not to fight with an army that has come from far away. It means that entering into the enemy's territory, far away from home, rather raises the morale and fighting strength of the army. Our army is small, but already in the enemy's territory. Although we ourselves are to fight, it is in accordance with historical lessons such as 'burning his own ships to fight' of Ming MENG, who served Duke Mu of Qin, and 'fighting with his back against the river' of Xin HAN, who served the Han Dynasty. Please let us fight again."

Dou XIN said, "the Art of War by Tzu SUN tells us that an obstinate attitude leads a small army to being captured by a large army. If the small army fiercely fights against the large army without considering the deference of their fighting strength, it will end up being captured. It is not a perfect plan to force tired soldiers to fight against the enemy that is increasing in number. We should withdraw."

The army was said to have decided to withdraw as a result of the discussion, and also due to the injury of Fu-heng LIU. However, as explained later, there is an opinion that the purpose of the expeditionary force to Japan in Bunei no Eki was, from the beginning, a kind of reconnaissance of the fighting strength and this conversation also might have been held based upon a withdrawal plan already made. For the ships of that time, it was dangerous to voyage towards the north from Hakata to Goryeo except on a sunny day with south wind, and sometimes it took a month in this season waiting for a good weather.

According to "Hachiman Gudokun," in the middle of the battle, a fire started, probably from firearms, in Hakozaki-gu Shrine, where warriors of the Kamakura shogunate decided as their base for interception and prayed for the gods' help, and it burned down the main building of the shrine, but they managed to save goshintai (object of worship believed to contain the spirit of a god) and other materials by carrying them out in a chest. It further says that at the midnight, about thirty people in white came out from burning Hakozaki-gu Shrine and shot arrows at the Yuan soldiers, who were horrified and hurriedly withdrew in their ships without waiting for dawn, and in this chaotic flight, the ships are said to have wrecked in the Genkai-nada Sea (even Korean envoys in the Edo period avoided crossing the Genkai-nada Sea at the night). However, these 'people in white' are so 'uncanny' that they are considered as a kind of 'manifestation of the power of the God of War in Hakozaki-gu Shrine' and not the warriors of the Kamakura shogunate nor any other actual force. According to "Hachiman Gudokun" and a copy of "Kanchuki," the Diary of FUJIWARA no Kanenaka (Kanenaka KADENOKOJI), the Yuan fleet disappeared on the following day and thus Bunei no Eki ended. "Genshi" do not particularly mention the damage suffered then in its 'Seiso Honki' (Records on Kublai) and 'Nihon Den' (Records on Japan), but "Koraishi" and "Koraishi Setsuyo" (Digested History of Goryeo) states that there was a storm at midnight, which caused shipwreck and damage, and more than 13.5 thousand people of the expeditionary force did not return to Gappo on December 26.

The well accepted theory says that Japanese samurai easily lost, because the only fighting method they knew was one to one battle by declaring their names, but fortunately the Yuan fleet was forced to withdraw within that night because of a storm, the so-called Kamikaze (divine wind). However, this is inconsistent with historical records. For details, refer to Kamikaze of Genko described later.

The Yuan army withdrew, and then the war with the Southern Sung Dynasty reached an important phase so, it was decided to send its main forces to the southern area of the Yangtze River.

There is a theory that Bunei no Eki would not have been an invasion, but rather a reconnaissance in force. This theory is persistent, based upon the following facts; the army of the Mongol Empire in many cases performed several reconnaissances in a phased manner before a serious invasion, with a number of soldiers varying from a hundred to ten thousand; arrows run short soon in the Yuan army as described in 'Nihon Den' of "Genshi;" and the number of soldiers was small, about thirty thousand (including non-soldiers). The Yuan Dynasty itself recorded in 'Nihon Den' of "Genshi" that arrows had run short, and therefore it is considered highly reliable. It is difficult to believe that it seriously tried to invade and conquer, or subject, with only about thirty thousand men and such a small number of arrows that soon run short, which was the main weapon of that time. Even in an open battle on the continent, one of the main tactics of the Yuan army was to damage the enemy by shooting arrows from horseback, maintaining certain distance from it and taking advantage of the mobility of the cavalry.

Koan no Eki

In 1275, Kublai sent envoys again to Japan, with assistant minister of rites Shizhong DU as chief envoy. Tokimune HOJO executed Shizhong DU and other four men at Tatsunokuchi Execution Site (near Eno-shima Island) (it is said to have been because the envoys were mostly spies in nature, recording and investigating the conditions of Japan in detail).

In 1279, without knowing the execution of the envoys, the Yuan Dynasty sent envoys again with Shufuku as their chief, in accordance with a proposal by Wen-hu FAN, who was the chief commander of the Southern Yangtze Army and used to be a vassal of the Southern Sung Dynasty, but all the envoys were executed in Dazai-fu (five in total according to the most accepted theory).

The conquest of the Southern Sung Dynasty in that year made it unnecessary for the Yuan Dynasty to align itself with Japan or warn against the Southern Sung Dynasty (refer to the relative paragraph described below), and further, Kublai became upset by the information brought by an escaped sailor about the execution of the envoys, particularly of Shizhong DU, who held a higher position (assistant minister of rites) than usual envoys, and consequently he planned to invade Japan again and in 1280 established the Eastern Expedition Field Headquarters to prepare for the invasion.

In 1281, an army of 140 thousand soldiers in total departed for Japan, consisting of the Eastern Route Army of 40,000 soldiers mainly from the Yuan and Goryeo army and the Southern Yangtze Army of 100,000 soldiers mainly from the former Southern Sung army.

However, Japan had already prepared defenses. It had built defense walls along Hakata Bay about twenty kilometers long to guard against the attack (Genko Borui). The strongest part of these defense walls is said to have measured three meters high and more than two meters thick. The Eastern Route Army arrived earlier and disembarked Shika no shima Island where there was no defense wall, but they were attacked by the Japanese army. The Japanese army, having learned the Yuan army's tactics in Bunei no Eki, fought with advantage and forced the Yuan army to withdraw into the sea. In addition, the Yuan army was bothered by many samurai attacking in small boats (while some of them, like Michiari KONO, suffered severe injuries from stone arrowheads).

The Southern Yangtze Army arrived later than the Eastern Route Army, for reasons including the substitution of commander-in-chief Arakan, who was the minister of the right and suffering from a disease, by Atahai, and the both armies joined near Taka-shima Island, Hirado. Then a storm occurred and the Yuan fleet could do nothing, but float. The samurai took this opportunity to attack the Yuan army and destroyed it. Most Yuan soldiers who had managed to disembark also perished by a surprise attack on Taka-shima Island by Suenaga TAKEZAKI and others on July 7 according to old lunar calendar (July 23 according to the Julian calendar). The Yuan soldiers who were able to return home are said to be from ten to twenty percent of the total number, including captives who were released later. The Japanese army is said to have killed people of Goryeo, Mongol, and Han, not trying to capture them, but saved people of the Southern Sung Dynasty, with which it had exchanges, and protected them with care. Tojin-machi in Hakata is sometimes referred to as a town of people from the Southern Sung Dynasty. In this battle, more than two-thirds of the Yuan navy forces were lost, and a considerable number of the battleships were also destroyed.

The number of soldiers who fought in Koan no Eki is said to have been about 140,000 held by Yuan and Goryeo (40,000 of the Eastern Route Army and 100,000 of the Southern Yangtze Army) and about 40,000 held by the Kamakura shogunate.

Damage inflicted on Japan

Koso Ibun Roku' (Record of the Writings Left Behind by the Founder) contained in 'Fukutekihen' reads as follows. This 'Koso Ibun Roku' is a collection of the writings left behind by Nichiren.

"In November 1274, the Mongol Empire attacked Tsukushi Province. People on Tsushima Island put up a defense, but Sukekuni SO and others escaped. As for the peasants, men were killed or captured. Women were gathered and hung on the ships' sides with their hands laced through, or captured. No one was spared. They also did the same at Iki Province."
It states that as for 'peasants,' meaning ordinary people, 'men were killed or captured' and in addition, 'women were gathered and hung on the ships' sides with their hands laced through, or were captured.'
It then continues, 'no one was saved,' which would mean neither men nor women. Similar cruel acts were done also in Iki.
The editor of 'Fukutekihen,' which contains this historical material, gives his comments as 'my opinion.'
He here explains that making a hole in the palms to lace a rope through was a traditional act continuing from ancient times in the Korean peninsula, taking 'Baekje,' which was the predecessor of Goryeo, for example. The editor concludes that this cruelty is the evidence of these acts having been committed by people of Goryeo. Nichiren mentions the tragedies in Tsushima, Iki, or mainland Kyushu in various sections in "Koso Ibun Roku."

Volume 5 'Mongol Invasion' of "Nichiren Chugasan" (Illustrated Biography of Nichiren) reads 'in Futajima, men were killed or captured. Women were gathered at one place and hung on the ships' sides with their hands laced through, and all captives suffered harm. In Hizen Province, several hundred people of the Matsuura Party were killed or captured. The people of this province, whether men or women, suffered the same fate as the people in Iki and Tsushima.'
"It brings me to tears to think that everyone may suffer the same fate as the people in Iki and Tsushima at that time." ('Ruisan Koso Ibun Roku' [Collected Records of the Writings Left Behind by the Founder], whose revised title is 'Ruisan Nichiren Shonin Ibunshu Heiseiban' [Collected Records of the Writings Left Behind by Saint Nichiren, Heisei Edition])

He also states in another section, "in Iki, Tsushima and the nine provinces of Kyushu, numerous soldiers and people, whether men or women, were killed, captured, threw themselves into the sea, or fell off a cliff" (the same book as mentioned above). The Yuan fleet that had invaded Tsushima and then Iki headed for Taka-shima Island. The army disembarked there. Hachiman Gudoki' (another title of "Hachiman Gudokun" and contained in "Fukutekihen") reads, "on the same day of sixteenth and seventeenth, many men and women were captured near Noko-no-shima Island in Hirado and Taka-shima Island. The Matsuura Party was defeated." "Men and women were captured" surely means that the enemy brought them home as captives.

At the time of Genko, Japanese people were scared by the attacks of the Mongol and Goryeo army, saying, 'moko kokuri no oni ga kuru' (the devils of the Mongol and Goryeo will come), which phrase later came to represent something scary, and thus a tradition spread to the whole country to scare children by saying 'mukuri kokuri, oni ga kuru' to make them behave themselves. There is a lullaby called Mokko no Komoriuta (in Kizukuri-machi, Aomori Prefecture) with lyrics of 'if you cry, Mongols will come from a mountain, don't cry and sleep,' representing the fear of the past Mongol invasion, and there are also other folk traditions across the country manifesting the fear of the cruel acts described above.

There is a theory that Genko provoked wako (Japanese pirates) to active operation in revenge (for details, refer to Wako).


Kublai seriously planned the third invasion of Japan and established again the Eastern Expedition Field Headquarters, which had been dissolved in 1287, appointing King Chungnyeol of Goryeo as minister. However, the successive occurrence of rebellions in the Yuan Dynasty during this period made it impossible to send an army to Japan, and following the death of Kublai, the plan was completely abandoned. Meanwhile, in November 1301, foreign ships appeared offshore near the Koshikijima Islands in Satsuma Province, and one of them made an attack. They are considered to have been the Yuan fleet that accidentally reached there and attempted to disembark.

After Bunei no Eki, bakufu intended to strengthen the defense of Hakata Bay. However, Japan gained nothing materially out of this war, and the rewards granted to vassals did not satisfy them. Some vassals, like Suenaga TAKEZAKI, even went to Kamakura to make a direct appeal to bakufu to obtain a reward.

After Koan no Eki, in order to prepare for the next attack by the Yuan army, bakufu tried to strengthen its control over the vassals, but the vassals came to live in debt because they did not receive sufficient rewards in Koan no Eki as well as Bunei no Eki. Bakufu issued a tokuseirei (debt cancellation order) to save the vassals from debt, but their frustration was not completely relieved.

Meanwhile, people in Japan then commonly believed, "what brought us the victory over the Yuan Dynasty was the power of language in poems created by nobles for victory and peace" or "it was shakubuku (to correct another's false views and awaken that person to the truth of Buddhism) and prayers performed by Buddhist and Shinto priests." In fact, from 1281 to the following year, a kind of Tokuseirei (ordering return of land sold and dissolution of debts) called 'Shinryo Kyogo' was issued for various shrines in Kyushu and Ise-jingu Shrine, ordering all land formerly owned by shrines, including the land granted to bakufu's vassals by its official letter, to be returned to the shrines.

In Japan at that time, people had a common idea of seeing the war against the Yuan Dynasty as the war between the Japanese gods and Yuan gods, and believed that the power of the Japanese gods would be strengthened by creating poems and performing shakubuku and prayers in shrines. It is called Tenjin Sokan Shiso (Idea of Correlation between Heaven and Man), and according to a widely-accepted theory, this idea led people to call the storm that saved Japan Kamikaze. It is also said that the event in which Kamikaze saved Japan led Japanese to widely believe in "Shinkoku Shiso" (the idea that Japan will never lose because it is a country protected by the gods), which became the grounds for the irrational idea held by the Japanese army and people at the end of the Pacific War, causing many tragedies, including Kamikaze Special Attack Units.

Changes in Japanese society having been progressing since the middle thirteenth century, such as the development of the monetary economy, hierarchization of the peasant class and formation of rural communities, were further accelerated by the influence of Genko. The class of Gokenin began to fall, and to the contrary, a new class of Akuto (a villain in the medieval times) emerged, and this change later led to the fall of the Kamakura bakufu.

Reasons for the Invasion of Japan

The reason for Bunei no Eki is considered to have been to warn against the Southern Sung Dynasty, and at least, in the beginning, Kublai did not desire to invade Japan. There is also a theory that they voluntarily withdrew after a short period.

The purpose was to see how Japan would react. It is called, in a military term, 'reconnaissance in force,' which is one of the very basic tactics.

Their aim was to damage Japan to some extent and force it to accept their demands in later negotiations. It is a tactic that the Yuan Dynasty often employed and this case seems to be in accordance with it.

It seems to be very reasonable, taking into consideration the reason for Yuan's sending envoys to Japan then and its circumstances.

Supporting evidence of the Yuan's purpose having been reconnaissance in force is a record in the Yuan Dynasty stating that the Yuan navy then had not prepared for a long battle so that it used all their arrows within one day and left.

On the other hand, there are various theories about Koan no Eki, which occurred after the fall of the Southern Sung Dynasty.

An unusual one says that the purpose was to weaken the former Southern Sung army, after its conquest, by forcing it to attack Japan. The former Southern Sung army had no loyalty to the Yuan Dynasty, because it was a conquered army, and furthermore, it had recruited soldiers through payment so that its soldiers were large in number but simple people who had low morale, loyalty, and fighting strength. It is also said that dissolving the army would cause social anxiety by producing numerous unemployed soldiers, but the Yuan Dynasty often sent local conquered soldiers to the next war and it could not be particularly emphasized only in the case of war with Japan.

Recent studies have found forks and spades used for farming in the Yuan's warship discovered at the bottom of Hakata Bay. Nihon Den of "Genshi," in the article of January 1281, says that Kublai, before sending the expedition army, summoned his commanders such as Arakan, Wen-hu FAN, Dou XIN, and Da-gu HONG, to Dadu and gave them an imperial order.
He then said, "I have heard that people of Han say, 'to seize home and country of others, you need to obtain peasants and land. If you kill all the peasants, for what use is the land that is obtained?'"
It is considered, therefore, that he would have been thinking about a long-term occupation and ruling of Japan for the purpose of land cultivation after winning the war of Koan no Eki. Some people consider that it indicates his intention of invasion, and out of 140,000 soldiers, whose number was excessively large, 100,000 soldiers of the Southern Yangtze Army, consisting of the former Southern Sung soldiers, would have been immigrants as well as soldiers.

Involvement of Goryeo

According to "Koraishi," in 1272, Crown Prince Sim of Goryeo (later King Chungnyeol) gave his opinion to Emperor Kublai of the Yuan Dynasty, "I think that Japan has not yet leant the virtues of the Emperor. Therefore, an imperial order should be issued to use the army, warships and provisions for this purpose. If you commission your vassals to do it, we will do our best to support the imperial army." In addition, "Genshi" states that Genko began with King Chungnyeol of Goryeo "persistently recommending an expedition to the east to Yuan's emperor in order to force Japan to become its subject." Concerning this, some try to find the reason for King Chungnyeol's opinion in the internal conditions of Goryeo. Before the invasion by the Mongols, the king of Goryeo was a puppet ruler, with warrior vassals controlling the government, but the king regained power by obtaining support from the Mongol army.
After that, the king of Goryeo became almost a member of the Mongol Empire, having received a Mongol name and become a son-in-law of the Mongol imperial family of Kublai (kuregen or guregen) by marrying his daughter, and thus Goryeo became 'Mongol's son-in-law kingdom of Goryeo.'
People objecting to it raised a rebellion, which was subdued by the Mongol, but some of them still continued fierce resistance. They were called Sambyeolcho. Some consider that King Chungnyeol gave that opinion in order to preserve the power of the king, by attracting the intention of Kublai. In addition, the reason for recommending the route via Goryeo among the three plans described above might have been to prevent the Mongol army from leaving Goryeo.

Letter from the Mongol Empire and the Killing of the Yuan Envoys

Concerning the first letter sent by the Yuan Dynasty, most scholars of eastern history think that it is surprisingly polite compared to letters by other Chinese dynasties, but scholars of Japanese history are said to have a tendency to see it as authoritative. Refer to Letter of the Mongol Emperor. Meanwhile, the reply that the Japanese Imperial Court intended to give, though it was not given because Tokimune HOJO opposed to it, is said to have contained rather aggressive phrases, saying "Japan is a country protected by the gods, originating from Amaterasu Omikami (the Sun Goddess), and thus there is no reason to obey a foreign country."

Concerning the killing of the envoys, some consider that the reason was because they were acting as spies. Before Bunei no Eki, envoys were rather free and could gather various information during their trips. It seems to have led the envoys to spy. "Hachiman Daibosatsu Gudokun" (another title of Hachiman Gudokun) reads, "they looked around Chikushi Province in the night and wrote instructions about the place for naval battle, position and the way to escape" and in addition, the records on Liang-pi CHAO in "Genshi" also says, "envoy to Japan Liang-pi CHAO reached Dazai-fu and returned with detailed information about Japanese titles granted to vassals, the number and names of provinces, customs and products." After Bunei no Eki, Japan killed envoys, probably being afraid of such spying. Some also consider that a decision was made, trying to solve the problem by force of arms, taking into consideration the nature of Kamakura bakufu as a military government, or trying to prepare the defense system by alerting its people about a threat from foreign countries.

There are both arguments for and against the killing of the Yuan envoys. At the time it occurred, it was criticized by Nichiren, and in a later era, there were both arguments for and against; some criticized it as a reckless act that gave the enemy a reason for the second invasion of Japan, and others affirm it, including Sanyo RAI and "Dainihonshi" (Great History of Japan), which states that it did not influence the Yuan's second invasion of Japan and is a good example to be followed when tackling a crisis of the nation.


Concerning the withdrawal of the Mongol army, Japanese historical materials only state the fact that the Mongol fleet disappeared the next morning. "Kanchuki," the Diary of noble Kanenaka HIROHASHI, reads that people then said that the upwind had blown. The historical materials of Goryeo, including "Koraishi," says that a storm occurred during their withdrawal and stranded many ships. However, the Japanese materials lack such descriptions. According to meteorology, there is no statistical record of the past that a typhoon came then, and therefore, some consider that it was a weather phenomenon other than a typhoon. Today, most people think that it is unlikely to have been a typhoon in relation to Bunei no Eki.

Also in Koan no Eki, what had destroyed the Southern Yangtze Army, which Japan could not know then, is said to have been a typhoon or tropical cyclone, but there is a theory that the Eastern Route Army staying offshore near Hakata perished due to a different reason.

Nowadays, there are many doubts about Bunei no Eki, including whether there was any serious damage, but what destroyed both armies of the Eastern Route and Southern Yangtze in Koan no Eki is still now widely considered to have been a typhoon, because there are diaries and records stating that even Kyoto had a furious storm from August 15, 1281 to August 16.

A military song called 'Genko' contains the lyric of "in the summer of the fourth year of Koan (1281)" but does not mention Bunei no Eki at all.

Military Aspect

It used to be said that Japan at that time fought basically by means of one-to-one battle against the Yuan army which fought in organized groups. It is also said that the Yuan army fought far better, by using weapons that the Japanese army did not have, such as poison arrows and guns. However, present studies have confirmed that both parties suffered damage, and therefore, there would have been cases in which Japan could employ a fairly large number of warriors and fought well.

Japan employed the following tactics and measures in Koan no Eki.

Defense using the defense walls mentioned earlier and shields. It is considered to have been a kind of act called 'building castle walls' in the Kamakura period (which meant preparing for a battle).

Surprise attacks in the night against the Yuan ships, departing from Japan in small boats. It was called 'attack in the night' and prohibited under the laws of Kamakura bakufu, but in Koan no Eki, bakufu proactively used this method. It is considered that Japanese samurai had an advantage in the battles in narrow spaces inside the ships.

The Southern Yangtze Army, which was to join the Eastern Route Army, was delayed about one and a half months because the army was disorganized due to the substitution of the commander-in-chief and confusion caused by a large number of soldiers.

On the other hand, the Eastern Route Army was forced to stay at sea near Hakata by successive attacks by Japanese commandoes, and soon became exhausted by the situation that would 'drive them into starvation,' due to the shortage of food and water as well as an epidemic.

The later departure of the Southern Yangtze Army coincided with the period of typhoon attacks, and the army was almost destroyed before it joined the other. The Eastern Route Army is also considered to have perished shortly after that, due to the same typhoon or tropical cyclone.

Although various other reasons are considered to have led to the defeat, one of the reasons was the fact that the Japanese army attacked the Yuan army in boats or on shore, before it disembarked, including the attacks described above. Since the Mongols were a nomadic people, they were not familiar with conducting battle in ships, and also could not use their cavalry, which they had been using well to achieve successive victories. It is also said that the fact that their ships had been made by people of subjected countries, such as Goryeo and Vietnam, was one of the reasons why many ships were so easily destroyed by the storm. They were already frustrated at the dominance of Mongols, and because constructing transport ships was an urgent mission, they cut corners to complete it early. The army also seems to have had a low morale because it consisted of various ethnic groups, including people of Goryeo and Han who had been conquered. According to a series of books written by Masaaki SUGIYAMA and page 449 of "Chugokushi 3" (The History of China, Volume 3) (published by Yamakawa Shuppansha) says that a purpose for organizing most of the Southern Yangtze Army with soldiers from the former Southern Sung Dynasty was to get rid of them, and they would cause social anxiety if left alone (in fact, to support this idea, no ship in which Mongol commanders were on board sank, and tombs of the soldiers joined in the Southern Yangtze Army have not been found in the former territory of the Southern Sung Dynasty). Meanwhile, the records on Bang-gyeong KIM in "Koraishi" says that Goryeo constructed the warships in Goryeo style, because constructing them in Southern Sung style was too expensive and would not be completed in time, and the situation was totally different from that suggested by King Chungnyeol, who told Kublai that the warships were ready to conquer Japan.