This is a detailed part of chapter 13|Late Kamakura Period, Genko 鎌倉末元寇). Please read chapter 13 before reading this section.
The red circle above indicates the time we discuss in this section.
Genko (元寇): Mongolian Invasion
13| Late Kamakura Period: Genko (鎌倉末元寇) described the Mongolian invasion simply. Here is a more detailed description. The Mongol Empire was a vast empire that spread between present Mongolia to Eastern Europe from the 13th to the 14th centuries. The grandson of Genghis Kahn, Kublai Kahn, sent several official letters to Japan demanding Japan to become a dependent state of the Mongol Empire (元: Yuan), and ordered to send a tribute to them. They threatened Japan that they would invade if Japan did not follow their demand. Hojo Tokimune (北条時宗), who was in power in Kamakura Bakufu (government) at the time, refused and ignored the letters many times. That led to the two-time invasions by the Mongol Empire. It is often said that the strong typhoon hit Japan on each occasion, and Mongols were pushed away by the two big typhoons. This is correct, but the real story had a lot more to it.
Bun’ei-no-eki (文永の役) 1274
The first Mongolian invasion was called Bun’ei-no-eki. In early October in 1274, Mongol troops (Mongols, Han people, and Koreans) of 40,000 men* departed from the Korean Peninsula on 900* large and small ships and headed to Japan. After they arrived on Tsushima island (対馬), Mongol troops burnt villages and killed many people, including the island people. Village people were captured and sent to the top officials of the Mongols as their slaves. It was a very sad scene.
The Mongols moved to Iki island (壱岐の島), to Hizen shore (肥前), to Hirado island (平戸), to Taka island (鷹島), then to Hakata Bay (博多). In each place, the disastrous sad scene was the same as everywhere. On each battlefield, Japanese soldiers and villagers were killed in large numbers. The Kamakura Bukufu sent a large number of Samurai troops to the battlefield. The Japanese forces sometimes won and pushed the Mongols back, but mostly lost. Many Japanese wives and children near the battleground were captured.
Eventually, no soldiers dared to fight against the Mongols. Mongols’ arrows were short and not so powerful, but they put the poison at the tip, and they shot the arrows all together at one time like rain. Also, this was the first time when the Japanese saw firearms. The loud sound of explosions frightened horses and Samurais.
Japanese troops had to retreat, and the situation was awful for the Japanese. But one morning, there was a big surprise! All the ships disappeared from the shore. They were all gone on the morning of October 21st (on today’s calendar, November 19th). All Mongols vanished from the shore of Hakata.
What happened was that the Mongols decided to quit the fight and went back to their country. The reason was that even though they were winning, they also lost many soldiers and one of the key person of the army. The Mongols realized that no matter how much they won, the Japanese kept coming more and more from everywhere. Also, the Mongols realized that they could not expect reinforcements from their country across the ocean. Their stocks of weapons were getting low. The Mongols decided to go back. Here was a twist. Around the end of October (November by today’s calendar), the sea between Hakata (where Mongols were stationed) and Korea was very dangerous because of the bad weather. Only a clear day with the south wind made it possible to sail over the sea. The name of the sea where the Mongol soldiers had to sail back is called Genkai Nada (玄界灘), very famous for the rough water. For some reason, the Mongols decided to head back during the night. That was a mistake. They may have caught a moment of the south wind, but it did not last long. As a result, they encountered a usual severe rainstorm. Many ships hit against each other, against the cliff, capsized, and people fell into the ocean. Several hundred broken ships were found on the shores of Japan.
The Mongol invasion ended here. This war is called Bun’ei-no-eki (文永の役). The Mongols lost a large number of people, ships, soldiers, food, and weapons. Actually, it was Korea that lost a great deal. They were forced to supply people, food, weapons, etc., by the Mongols. After the war, in Korea, only older men and children were left to work on the farm. On top of it, they had a drought and prolonged rain.
Ko’an-no-eki (弘安の役) 1281
The second Mongolian invasion is called Ko’an-no-eki in 1281. After the first attempt to invade Japan, Kublai Khan kept sending messengers to Japan to demand it to become Mongol’s dependent territory. The Kamakura Bakufu kept ignoring and killed messengers. Kublai Kahn decided to attack Japan again in 1281. The top advisers of Kublai Kahn tried to convince him not to do it because the ocean was too dangerous, the country was too small, the place was too far, and there would be nothing to gain even if they win. But Kublai Kahn still insisted on attacking.
This time they came in two groups. One was the East-route troop with 40,000* soldiers on 900 ships, and the other was the South-route troop with 100,000* soldiers on 3,500 ships. This was the enormous scale of forces in history. They planned to depart from each designated port, and they planned to join on the Iki Island (壱岐の島) by June 15th, then work together. The East-route troop arrived there before the South-route troop. Instead of waiting for the South-route troop to come, the East-route troop started to attack Hakata Bay (博多) on their own. But since the previous invasion of the Bun’ei-no-eki, Japan had prepared to fight and built a 20-kilometer-long stone wall. This stone wall was 3 meters high and 2 meters thick. The East-route troop had to give up to land from Hakata and moved to Shika-no Shima Island (志賀島). In this place, the fight between Mongols and Japan was even, but in the end, the East-route troop lost and retreated to Iki Island, and decided to wait for the South-route troop to arrive.
The South-route troop never came. They had changed their plan. On top of that, while the East-route troop was waiting for the South-route troop to arrive, they lost over 3,000 men over an epidemic. Some suggested going back home with difficulty like this, but they concluded to wait for the South-route troop as long as their food would last.
Meanwhile, the South-route troop decided to go to Hirado Island (平戸島), which was closer to Dazaifu (太宰府). Dazaifu was the final and most important place they wanted to attack. Later, the East-route troop found the South-route troop went to Hirado Island. Finally, two forces joined on Hirado Island, and each group was stationed on the nearby island called Takashima Island(鷹島). The problem was that since this island had very high tide and low tide, the ships were not easily maneuvered.
In the meantime, 60,000 Japanese men were marching toward the place where the Mongols were stationed. Before Japanese soldiers arrived to fight against the Mongols, a big typhoon came on July 30th, and Mongols were caught in a big typhoon. Their ships were hitting each other, and many sank. People fell from the boats and drowned.
By this time, it had been about three months after the East-route troop left Mongol in early May. That means they were on the ocean for about three months or so. In the northern Kyushu area (九州), typhoons usually come, on average, 3.2 times between July and September. The Mongols were on the ocean and Japan’s shorelines for about three months. They were bound to be hit by a typhoon sooner or later.
The Mongol Empire lost 2/3 of its naval forces in the event of Ko’an-no-eki. Even after the Mongols failed the two invasions, Kublai Khan still insisted on attacking Japan again, no matter how his advisers reasoned him not to. In the end, the plan was delayed and terminated because of many rebellions and upheavals, and no lumber was left to build ships. Soon later, Kublai died in 1294. The historical record of Mongols indicated that Mongolian officials highly praised Japanese swords. Some even say one of the reasons why it was not easy to defeat Japan was their long sharp swords. The experience of the Mongolian invasion changed the Ikubi kissaki (猪首切先) sword to the new Soshu-Den (相州伝) style sword. The next chapter describes a new style of sword, Soshu-Den swords.
The stone wall scene. Photo from Wikipedia. Public Domain
* Number of soldiers by https://kotobank.jp/word/元寇-60419 . Several different reference sources have a slightly different number of soldiers and ships, but they are similar numbers.