Have you ever heard about the first time Japan faced a full-scale foreign invasion?
That moment came in the 13th century when the mighty Mongol Empire twice attempted to conquer the island nation in events known as the “Mongol Invasions” or “Genko”.
Against the backdrop of a nomadic horse-riding Mongol army that had swept across East Asia, the samurai of the Kamakura period, armed with their bows and swords and fueled by the spirit of Bushido, rose to defend their homeland.
Despite facing gunpowder weapons that were unfamiliar to them, their unwavering spirit and exceptional martial skills ultimately thwarted the invasions in a dramatic clash of “Samurai vs. Nomadic Horsemen”.
How did Japan confront this unprecedented crisis and ultimately achieve victory?
The story involves the Mongol Empire’s grand ambitions, the tragic events on the islands of Tsushima and Iki, and the resolute determination of the Kamakura Shogunate.

Background to the Mongol Invasions: The Yuan Dynasty’s Ambition and Demands on Japan

In the 13th century, the Mongol Empire, under the successors of Genghis Khan, had expanded its power across the entire Eurasian continent.
Among them, the fifth Khagan, Kublai Khan, established the Yuan Dynasty in China in 1271 and set his sights on further territorial expansion.
His attention turned towards Japan, an island nation in the eastern sea.
Having already brought the Korean Peninsula under his control in 1259, making Goryeo a vassal state, Japan was an unavoidable obstacle for the Yuan in establishing complete dominance in East Asia.
Kublai Khan viewed Japan’s independence as a potential threat to the security of his empire.
The Mongol Empire held a universalistic ideology, believing that all nations should submit to its rule.

Initially, Kublai Khan attempted to bring Japan under his control through diplomacy rather than military force.
Between 1266 and 1273, he dispatched six missions of Mongol and Goryeo envoys to Japan, demanding submission.
However, the Kamakura Shogunate flatly rejected these demands.
The letters sent by Kublai Khan insulted the Japanese Emperor by addressing him merely as a “king,” which provoked strong resentment in Japan.
Hojo Tokimune, the Shikken (regent) of the Kamakura Shogunate, believed that Japan could confidently handle any threat from the continent and maintained a stance of ignoring the Mongol demands.
Behind the Shogunate’s firm attitude were a lack of knowledge and experience regarding international affairs, an underestimation of the Yuan’s power (possibly influenced by information from Southern Song monks), and, above all, a resolute refusal to become a Mongol vassal state. The repeated failures of diplomatic negotiations heightened tensions between the two nations, making armed conflict increasingly inevitable. Japan’s alliance with the Southern Song Dynasty might have also distorted the Mongol perception of Japan.

The Mongol desire to invade Japan was driven not only by political reasons but also by economic motives.
At the time, Japan was known in East Asia as a wealthy country with abundant gold resources, a fact even mentioned in the writings of Marco Polo in distant Europe.
Kublai Khan aimed to seize Japan’s wealth and increase the financial power of his empire.
Furthermore, by conquering Japan, which maintained its economic strength through trade with the Southern Song, the Yuan also intended to cut off the Southern Song’s economic lifeline and weaken it strategically.
Hakata was an important trading hub with the Southern Song, and many Song merchants resided there.
Placing Japan under Yuan control would also provide the empire with new manpower and resources, which would be crucial for advancing the war against the Southern Song.
Additionally, the Mongol Empire aimed to conquer the entire Asian continent, and securing an outlet to the Pacific Ocean was another strategic goal that likely motivated the invasion of Japan.

Source: https://ja.wikipedia.org/wiki/%E3%82%AF%E3%83%93%E3%83%A9%E3%82%A4

The Battle of Bun’ei (1274): The First Invasion and the Battle of Hakata Bay

As diplomatic negotiations repeatedly failed, Kublai Khan finally decided to conquer Japan by force. In November 1274, the first Mongol invasion fleet, consisting of approximately 800 to 900 ships and 28,000 to 30,000 soldiers including Mongols, Chinese, and Koreans, set sail for Japan from Goryeo.
The vassal state of Goryeo significantly contributed to the construction and logistics of this large-scale invasion fleet.

The Mongol army first attacked and occupied the islands of Tsushima (November 4th) and Iki (November 13th).
The defending soldiers of the islands fought bravely, but they were successively overwhelmed by the numerically superior Mongol forces.
Then, on November 19th, the Mongol army finally began landing on the shores of Hakata Bay in Kyushu.

Against the Mongol forces that landed in Hakata Bay, approximately 10,000 Japanese defenders, mainly samurai from Kyushu, stood ready.
Major battles included the Battle of Tsushima led by So Sukekuni, the Battle of Iki commanded by Taira no Kagetaka, and the battles around Hakata Bay at Torikai-gata and Akasaka.
The flames of war even reached Hakozaki Shrine, causing damage such as the burning down of its main hall.

The Mongol army employed advanced tactics and weapons unseen by the Japanese army at the time, including disciplined cavalry engaging in group combat, organized command using drums and gongs, powerful composite bows, armor-piercing crossbows, poisoned arrows, and even gunpowder bombs launched by catapults.
The gunpowder weapons, in particular, greatly perplexed the Japanese samurai.
Influenced by the code of Bushido, which emphasized individual combat, the Japanese samurai were not accustomed to group tactics or long-range attacks.
However, the samurai resisted bravely, utilizing their sharp swords and armor to gain an advantage in close combat.
They also employed guerrilla tactics to counter the Mongol fighting methods.

After a day of fierce fighting, the Mongol army suddenly withdrew to their ships.
There are various theories about the reason for this retreat, including supply issues, the death of a Mongol general, or that it was for reconnaissance purposes.
That night, Hakata Bay was struck by a violent storm, causing significant damage to the Mongol fleet.
This storm would later be referred to as the “Kamikaze,” meaning “divine wind”.
Having suffered devastating losses, the Mongol army was forced to retreat to Goryeo.

The Mongol forces that attacked Tsushima and Iki mercilessly slaughtered the resisting inhabitants.
Captured islanders were sent as slaves to high-ranking Mongol officials.
On Tsushima, a cruel act of piercing the palms of prisoners with wire and hanging them from ships was also recorded.
On Iki, there were instances where captured Japanese were used as shields.
Taira no Kagetaka, the governor-general of Iki, chose to take his own life along with his wife and children rather than be captured.
The barbarity of the Mongol army on these islands was reported throughout Japan, instilling strong anger and fear among the people and solidifying their determination for the subsequent defensive battles.

Source: https://www.crossroadfukuoka.jp/feature/genko

The Battle of Koan (1281): The Second Invasion and the Divine Wind

After the first invasion, the Kamakura Shogunate strongly anticipated a second Mongol invasion and reinforced its defense system.
Starting in 1275, a massive stone wall, approximately 20 kilometers long and up to 2.8 meters high, was constructed along Hakata Bay.
This wall played a significant role in preventing the Mongol army from landing during the second invasion.
The Shogunate also strengthened the mobilization system for the samurai in Kyushu and tightened security along the coast.

Meanwhile, undeterred by their initial defeat, Kublai Khan planned a second invasion of Japan in 1280.
This time, the invasion force was far larger than the previous one, consisting of the Eastern Route Army (mainly Koreans and Mongols) of about 40,000 men and 900 ships departing from Goryeo, and the Southern Route Army (mainly Chinese) of about 100,000 men and 3,500 ships departing from southern China.

On June 23, 1281, the Eastern Route Army arrived first at Hakata Bay.
However, the stone wall built by the Japanese forces was sturdy, and the Mongol army could not easily land.
As a result, the fighting centered on naval battles.
Japanese samurai, using small boats, launched nighttime surprise attacks on the Mongol fleet, inflicting heavy damage and significantly lowering the enemy’s morale.
Major battles took place off the coasts of Tsushima (June 9th), Iki (June 14th), Shiga Island, and in Hakata Bay.
Some attempted landings were made on Nagato in Honshu but were repelled.
The Southern Route Army finally joined them in mid-August.

Then, on August 15th, a massive typhoon once again struck the Tsushima Strait, devastating the Mongol fleet.
According to Japanese records of the time, over 4,000 ships were lost in this storm.
Many Mongol soldiers who washed ashore were executed by the Japanese forces.
The two Mongol invasions were both thwarted by typhoons, which came to be known as the “Kamikaze”.

During both invasions, the Mongol army used gunpowder weapons.
These included hand-thrown bombs (early hand grenades) and flamethrowers called “fire lances,” which were completely unknown weapons to the Japanese at the time.
These weapons confused and terrified the Japanese samurai and their horses with their explosive sounds and flames.
Archaeological evidence, such as ceramic spheres filled with metal and pottery fragments discovered off the coast of Takashima in Nagasaki Prefecture, confirms the use of bombs.

Initially, the Japanese samurai were bewildered by these unfamiliar weapons and tactics.
Their traditional fighting style, centered on individual duels, was not always effective against the Mongol army, which excelled in organized group tactics.
Furthermore, the short composite bows used by the Mongols had a longer range than the Japanese longbows.
However, the long and sharp Japanese swords (tachi and later katana) proved effective in close combat against Mongol armor.

Over time, the Japanese samurai adapted to the Mongol tactics, learning to fight in groups and developing strategies to counter the enemy’s methods.
The Mongol invasions became one of the catalysts for the modernization of Japanese military practices, and the spear (yari) became more commonly used.

Source: https://www.crossroadfukuoka.jp/feature/genko

The Power of Bushido: The Spirit, Archery, and Swordsmanship of the Kamakura Samurai

The greatest factor in repelling the two Mongol invasions was the indomitable spirit, bravery, discipline, and loyalty to their lord of the Kamakura samurai, rooted in the spirit of Bushido.
Their strong will to defend their country, without fear of death, became the driving force behind repelling the mighty Mongol Empire.

The samurai were skilled in archery using the yumi (Japanese bow) and swordsmanship using the tachi and katana, demonstrating their abilities to the fullest, especially in close combat.
Although initially struggling with the range of the Mongol bows, they bravely engaged in close-quarters fighting, countering with their superior swordsmanship.

Furthermore, the strong stone wall built along Hakata Bay significantly hindered the Mongol army’s landing during the second invasion, greatly contributing to Japan’s defense.
And above all, the existence of the typhoons, known as “Kamikaze,” which saved Japan twice, instilled a sense of divine protection (Shinkoku shiso) among the Japanese people, strengthening their belief that their land was protected by the gods.
Additionally, the Japanese samurai employed defensive strategies and guerrilla tactics that utilized the terrain, troubling the Mongol army.
Japan’s victory was a result of the samurai’s unwavering spirit and martial skills, robust defenses, and the power of nature combined.

The Shogunate’s Decision: The Execution of Mongol Envoys

The Kamakura Shogunate, particularly the Shikken Hojo Tokimune, showed a firm stance of refusal towards Kublai Khan’s demands for submission.
Following the first invasion and reports of the Mongol army’s atrocities on Tsushima and Iki, the Shogunate’s attitude towards negotiation hardened further.
Kublai Khan dispatched envoys to Japan again in 1275 and 1279, demanding tribute and even requesting the Emperor to visit his court.
However, Tokimune took the unprecedented and drastic measure of executing these envoys in 1275 (near Kamakura) and 1279 (in Hakata).
This act was a significant departure from diplomatic protocol.
This resolute action demonstrated the Shogunate’s strong will to protect Japan’s sovereignty and independence.

The Legacy of the Mongol Invasions: Significance in Japanese History

The Mongol Invasions marked the end of the Mongol Empire’s expansion and are positioned as a crucial event in Japanese history, one where the nation’s survival was at stake.
Repelling the two invasions strengthened the belief that Japan was a divine nation, fostering a strong sense of unity and national consciousness among the people.
The term “Kamikaze” in particular became deeply ingrained in Japanese military thought as a symbol of divine protection.

Furthermore, the achievements of the Kamakura samurai in preventing the Mongol invasions greatly enhanced the status and authority of the warrior class.
This war served as an opportunity for the evolution of Japanese military technology and tactics.
The importance of coastal defense was recognized, and efforts were made to adapt to group tactics and new weapons.

However, the economic burden of preparing for the second invasion and the inability to adequately reward the samurai who had distinguished themselves in battle led to growing dissatisfaction within the Shogunate, contributing to the decline of the Kamakura Shogunate.
The Mongol Invasions were the only large-scale foreign invasions of Japan until the threat from Western powers in the 19th century, and they influenced Japan’s subsequent foreign policy, including the policy of national isolation (Sakoku).

A Thrilling Conclusion: The Soul of the Samurai Lives Forever

Two invasions by the Mongol Empire. The Kamakura samurai, though initially bewildered by gunpowder weapons, stood firm with the spirit of Bushido in their hearts, bravely fighting with bows and swords.
And the “Kamikaze” that saved Japan not once, but twice. The Mongol Invasions were an unprecedented crisis in Japanese history, but the courage and determination of the samurai, combined with the power of nature, brought about a miraculous victory.
The soul of the samurai demonstrated in this battle has been passed down through subsequent Japanese history, forming the foundation of the Japanese spirit.

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