2.25. History of the Mongols: Invasion of Japan and Battle of Tsushima

For the release of the new Sucker Punch video game, Ghost of Tsushima, which depicts a lone samurai defending a Japanese island from Mongol invaders, we’re going to change up our presentation for a few episodes.  This will be the first in a three part series looking at the Mongol invasions of Japan, a slight jump ahead in the timeline of our episodes so far, going from the reign of Great Khan Mongke to that of his younger brother, Kublai Khan. This first episode will provide greater context to the game, discussing the cause of the first Mongol invasion of Japan in 1274, the actual battle for Tsushima island and the fighting in Hakata Bay.  Our following episode will detail the story of Takezaki Suenaga, a samurai who fought against both invasions and later produced a brilliant set of scrolls depicting his exploits. The final episode will cover the oft-overlooked consequences of the invasion on both Japan and Kublai Khan’s empire, as well as its historical legacy: altogether, we hope to provide an accurate and well rounded view of the historical events surrounding the game utilizing both primary sources and scholarly literature. I’m your host David, and this is Kings and Generals: Ages of Conquest.

 

    Japan first came to Mongol attention through Japanese raids against the Korean peninsula. Called wakō, piracy against the Korean coastline had existed for centuries, but picked up again in the 1220s during Korean weakness caused by the Khitan and Mongol invasions, covered in our previous episodes. The island of Tsushima, situated between Korea and Japan, was a prominent base for these pirates making the short trip over the straits to strike undefended settlements. These attacks were not court sanctioned, a crime of individual opportunity rather an organized effort. By the time the Korean leadership finally submitted in 1259 the raids had largely ceased, but it meant the existence of Japan was known to the Mongols. The new King of Korea in 1260, King Wonjong, had a good relationship with the new Mongol Emperor, Kublai. We will return to Mongke’s reign after these episodes, but for those of you who do not know, Mongke Khan died on campaign in China in August 1259. Two of his younger brothers, Kublai and Ariq Boke, both declared themselves Khaan in the months following. Known as the Toluid Civil War, Kublai based in China was able to overcome his brother based in Mongolia by 1264. Consequences were immense: Mongol imperial unity was shattered as the Mongol ruled Khanates across western Asia began their own conflicts, the Hulegu-Berke war between the Ilkhanate and Golden Horde. Kublai had defeated Ariq, but lost the empire. His authority beyond the western borders of China was only nominal, and the Khanates were effectively independent states from that point on, though contact remained between them. Kublai, by necessity, was forced to focus his continued conquests on China and the surrounding territories. 

    Kublai’s main target was the Song Dynasty, which ruled southern China. A huge economic power with a massive population, the Song war was a difficult task. The Mongols needed to resort to indirect strategies to help bypass the frontier: in the 1250s, Kublai had conquered the Kingdom of Dali, in China’s modern Yunnan province, to open a front on the southwest of the Song. The Japanese, who had trade ties with the Song, were another direction Kublai could exert his influence. Forcing the Japanese to cut trade with the Song would help weaken the Song economy, and so aid Kublai’s overall war with them. Further, like his brother Mongke, Kublai firmly believed in the eventuality that all of the world was to come under Mongol rule. Bringing in the submission of the Japanese was merely Kublai enacting heaven’s will. He had one other concern that his predecessors did not. Despite controlling Mongolia, the core of Kublai’s realm was China, and tied himself to Chinese imperial tradition for legitimacy there. In classic Chinese tradition he declared his own dynasty in 1271, the Yuan Dynasty, marking himself as heir to the Chinese empires of Han, Tang and successor to the dying Song Dynasty. In the days of the mighty Tang Dynasty, ruling from 618-907 CE, Japan had diplomatic, economic and religious ties with China, and the Tang Emperors considered the Japanese their vassals. These ties petered out before the end of the Tang, and only during the years of the southern Song was there even trade between them. For Kublai, to vassalize Japan would help to legitimize him to the Chinese, bringing Japan ‘back into the fold,’ so to speak. With these various interests in mind, in 1266 he ordered a first set of envoys to travel to Japan via Korea.

 

    Kublai addressed the letter to the King of Japan, and it's here we can discuss a rather unique feature of Japanese government of the time. Firstly, Japan’s official ruler was not the ‘King,’ but the Emperor, at that time Emperor Kameyama, the 90th emperor of Japan. However, since the end of the Genpei War in 1185, the emperor was a figurehead, with real power held by the Shogun. Known as the Kamakura Bakufu, based in the city of Kamakura, the Shogunate was founded by the fearsome Minamoto no Yoritomo, military rulers exercising real authority with the imperial court relegated to ceremonial and religious roles. However, on Yoritomo’s death in 1199, he was succeeded by his young son as shogun. The boy too young to rule, real power was held by the family of Yoritomo's widow, the Hojo clan. Sidelining and replacing shoguns as necessary, for well over a century, Japan was ruled by the regent of the regent, called the shikken. In 1268, the 17 year old Hojo Tokimune became shikken, the de facto ruler, of Japan.

 

    Though Kublai’s envoys in 1266 turned back before they reached Japan, he was not discouraged. Envoys were sent again in 1268, taken aboard Korean vessels specifically instructed not to return without handing off Kublai’s letter. The letter was not as demanding as earlier Mongol missives of the century, but still referred to Kublai as master of the universe, and informed the Japanese that they should open contact with him, for, as Kublai’s wrote at the end of the letter, “Nobody would wish to resort to arms.” It was a tough position for the Japanese, as they knew next to nothing of the Mongols. What they did know, they had learned from merchants or Buddhist Monks from the Song Dynasty, at war with the Mongols since 1234. Having not engaged in actual overseas diplomacy since the 9th century, there was no experience within the court or the Bakufu on how to react. So, the chosen Japanese response was to simply dismiss the envoys with no official response, per the order of the shikken. Ghosting the most powerful monarch on the planet is not a terribly easy thing to do, however.

 

    Later that same year, Kublai ordered the Koreans to build 1,000 warships and conscript 10,000 men, for use against the Song Dynasty or Japan. Later in 1268, he sent a third embassy, which in the first months of 1269, stopped on the island of Tsushima and turned back, but not without first capturing two local fishermen. Brought all the way back to Kublai’s imperial capital of Dadu, modern day Beijing, they were wined and dined by the mightiest man under heaven. Showing off his splendour and unimaginable power, the Khan of Khans told the fishermen he only wanted to have his envoys reach Japan, and to have his name remembered for all time. Was that so much to ask? The fishermen were escorted back to Japan late in 1269 to bring word of Kublai’s desires and his great power, and were promptly ignored by the Bakufu. The ongoing insolence of the Japanese was not something Kublai could ignore. 

 

    A diplomatic solution was still preferable, as the war with the Song Dynasty was still ongoing and in 1269 revolt broke out in Korea due to the onerous demands for materials and men. As we discussed in the previous episode, Korea had suffered under near continuous Mongol attacks from 1231 until 1259, and the population struggled to meet the latest demands. It took until the middle of 1271 for the rebellion to be crushed, but by then some Koreans had brought word to Japan of Mongol preparations. Since 1268, some coastal defenses had started to be rallied, but news of the proximity of the danger caused quite the start in the Bakufu. No aid was sent to Korea despite the requests of the defectors, but more warriors began to be mobilized to the island of Kyushu, the westernmost of the five main islands of Japan and most likely site of attack. Mongol envoys returned in 1271 after Korea was pacified, now with a direct threat of invasion if the Japanese failed to reply.  The envoy returned to Korea empty handed by the end of the year, and after trips back to Japan in 1272 and 1273, he finally came to Kublai with news of his failure. The envoy had spent some time in Japan while trying to get the court’s response, so at least he brought the Khan intelligence on the people, land and defences. This was enough for Kublai. Sending more envoys would only make him look toothless. His armies had just taken the major Song Dynasty stronghold of Xiangyang in 1273, the key to southern China. With the Song poised to fall, Kublai could spare forces to punish Japan. 

 

    The final preparation for the invasions were carried out over 1274, and departed from southern Korea that November. It was not a massive army, some 15,000 Mongol, Northern Chinese, Khitan and Jurchen troops, 6-8,000 Korean troops, another 7,000 Korean sailors aboard some 8-900 ships. Prince Khindu served as overall commander, with Mongol, Chinese and Korean generals and admirals. The Mongols had little naval experience beyond fighting on rivers in South China, so were reliant on the knowhow of the Koreans for this aspect. Once they made landfall, the Mongols would take care of the rest. The Mongols had overcome every foe they had faced in the 13th century: Kublai imagined a swift victory against the insignificant island of Japan, for Eternal Blue Heaven mandated nothing less. Late on the 4th of November, 1274, the fleet was spotted off the coast of Tsushima. 

 

    The island of Tsushima was controlled by the Sō clan, whose head, Sō Sukekuni, was the deputy shugo, military governor. Per the tradition held in the Japanese chronicle, the Hachiman Gudokun, on Tsushima there was a major shrine to Hachiman, the Japanese god of war. The day of the Mongol approach, a fire broke out at the shrine, a bad omen. Once the fire was extinguished, white doves gathered on the shrine’s roof. As doves were the messengers of Hachiman, Sukekuni saw it must have been a warning from Hachiman: surely, he would not have set his own shrine on fire? Indeed, later that day Sukekuni was alerted that a fleet was seen approaching the island. His garrison was mobilized, some 80 Samurai and their retainers who he led to the beach of Komoda; there, they awaited the dawn and the Mongols. 

 

    Sukekuni sent a small vessel out as the Mongols neared the beach to inquire as to their intentions. His envoys were rebuffed and the landing ships neared the beaches, forcing Sukekuni to draw his small force up for battle. While famous for their swordsmanship, the 13th century Samurai was primarily a horse archer like the Mongols. With their long, asymmetrical yumi, the iconic bow of the Samurai, their skill and accuracy with the arrow made them deadly. However, the desire for individual glory and distinction in combat preempted them from utilizing the complex unit tactics, repeated hit and runs, skirmishing and feigned retreats which made Mongol horse archery so tactically powerful. When the ships landed under the command of the general Ho-tun, the first troops sent up the beach were likely those considered expendable- i.e, anyone not Mongolian. Poorly armoured Chinese were rushed off the ships and met with Japanese arrows. They suffered under this withering fire, but the Chinese and Koreans did their job, holding up large wicker shields to soak up arrows while the Mongols had time to disembark and prepare their own horses. Sukekuni’s position was overrun, despite withdrawing to the treeline to face the Mongols in close combat where the Samurai were deadly. One of Sukekuni’s comrades took down several advancing soldiers and a Mongol officer, and standing on the body he shouted threats at the Mongols, daring them to face him in battle. The Mongols responded with arrows, piercing the man’s chest armour and ending his boasts. Sukekuni led one final charge against the Mongols before the last of his men were cut down. The Mongols overran Tsushima from November 5th until the 13th, destroying towns, farmland and annihilating the last strands of resistance. The women of the Sō family committed suicide so as to not fall into Mongol hands. The next island to face the fleet, Iki, was greeted by a gruesome sight. Attested in both Japanese and Yuan Dynasty sources, prisoners, mainly women, had wire threaded through their palms and were strung across the prows of the ships in a horrific necklace.

 

    The island of Iki too fell within a day. Several small islands and the Matsuura peninsula were taken after only token resistance as the fleet neared  the northwestern corner of Kyushu and Hakata Bay, the island’s largest natural harbour. It made an ideal landing point for any large army. Hojo Tokimune knew this, and here had collected his warriors. The defensive force was mainly drawn of men from Kyushu, though the mobilization had been extended to parts of western Honshu, the largest Japanese island, in 1274. Exact figures for the Japanese force are uncertain, but were outnumbered. 4-6,000 is a common estimate, against over 20,000 of the Yuan fleet- though the main source for the Mongol side, the Yuan shi, states 102,000 Japanese were arrayed against them. 

 

    Landing on the soft sand beaches of Hakata Bay on November 19th, the Chinese and Korean infantry protected by their large shields and long spears disembarked; following were Mongols, Turks, Khitans and Jurchen leading their horses out and mounting them. Traditionally, the Japanese began battle by sending arrows with holes dug through the head, creating a whistling sound as they went through the air. The Mongols, who used such things often for communication in battle, laughed. The beating of drums and gongs signalled Mongol orders; unused to such noise, the Japanese horses panicked. Samurai riding forward to challenge worthy opponents to single combat were met with arrows, and those who tried to ride individually through the thickly pressed enemy line were cut down.. The Japanese sources accused the Mongols of using poisoned arrows, which sickened the men struck by them. Bombs, made of paper or iron and filled with Chinese gunpowder, were lobbed into the Japanese who had never experienced such things- the flash, the noise and smoke injured, disoriented and frightened them.

 

    The Mongols, advancing or retreating as ordered and in unison, were an unnerving sight to Samurai used to smaller, individually led combat. Over the course of the day the Japanese were pushed from the beach and their defensive line was broken through. Fires were set on the nearby town of Hakata, which spread quickly. Another force broke out and tried to make camp at Akasaka, but were repulsed. Once past the initial surprise of the assault, the Japanese archers made a good show of themselves. Every samurai trained since a young age with a bow, and the accuracy and power of their bows took even the Mongols by surprise. Small Mongol parties isolated from the main force were picked off, and one of the top Yuan commanders, Liu Fuxiang, was struck in the face by a Japanese arrow and had his horse stolen. The gravely injured commander was rushed back to the ships. Japanese resistance had proven stiffer than anticipated, and the overconfident Yuan forces had suffered losses for this. Divisions and language barriers in the leadership hamstrung them, and uncertain of moving further inland in unknown territory without reinforcement, by nightfall it was decided to call a retreat. 

 

    The Yuan forces returned to their ships and set out for Korea, at which point we get to the most well known aspect of the invasions. Very few contemporary Japanese sources mention divine favour or wind in regards to the withdrawal, at most, stating strong winds pushed the armada back to Korea. One of the main Japanese sources, the Hachiman Gudokun, states the defenders were surprised to find the fleet gone in the morning, only a single ship having run aground. In sources from the Mongol point of view though, we have the most dramatic presentation. The Yuan shi, compiled in the 1370s from Mongol documents, describes the Mongols having crushed the Japanese and needing to withdraw for they had ran out of arrows. On the way back, they were struck by an almighty storm, losing many ships in the ocean. This emphasis by the Mongols is obvious: by blaming a freak weather accident, the retreat was easier explained, rather than give credit to the Japanese fighting harder than the Mongols had expected. Whatever the fact of the storm was, the first of the so-called kamikazes, the Yuan fleet had begun to withdraw before it struck. In the words of historian Thomas Conlan, the Japanese were “in little need of divine intervention.”

 

    Neither side saw this as inconclusive though. The Japanese anticipated a Mongol return, and further preparations were made, such as building a wall for dozens of kilometres along Hakata Bay and preparing to quickly mobilize samurai if needed. For Kublai, this had been but a small force, a taste of what he could throw against Japan. He sent envoys again in 1275 to the bakufu, who were killed by the Japanese, ensuring the Khaan would need to send an armed force once more. Once Kublai completed the conquest of the Song Dynasty in 1279, he turned his attention to a massive invasion to subdue Japan once and for all. 

 

But the second invasion is a topic for another day. Our next episode will come out this Friday, looking at the story of Takezaki Suenaga, a historical samurai who fought in both invasions and later compiled an excellent set of scrolls presenting his exploits. Through him, we’ll get a chance to talk in-depth on the Japanese defence, tactics and more. If that isn’t enough, we’ll have another episode coming out after that discussing the impact of the invasions on Japan and the Mongol Empire. But that’s not all: check out Kings and Generals on Youtube for a video this Thursday on the battles for Tsushima and Iki islands, the direct inspiration for the game. As well, the narrator for Kings and Generals will actually be playing Ghost of Tsushima on a livestream this weekend. Our writer for this series will be there as well, so prepare any questions you have for him and he’ll do his best to answer. If you’d like to help us continue bringing you content, please consider subscribing to our Patreon at www.patreon/kingsandgenerals.com. I’m your host David, and we will catch you on the next one.