Mongol Invasions of Japan

The Mongol Invasions of Japan were the attempts of conquering Japan by the armies the armies of Kublai Khan. They consisted of two invasions which forced the Samurai into a corner to defend their homeland, outmatched at first by superior weapons and unfamiliar battle tactics. The invasions were influential on Japanese history as they changed the nation to its core, forcing the Samurai to change their weapons, tactics and morals.

Calm Before the Storm
The Mongolian leader announced his intentions of conquering the islands of Japan via a message to the Japanese Emperor demanding a tribute in 1266. The Emperor sent no reply, which only angered Khan, who continued to send five messages over of a period of six years. Khan, who controlled much of China, Korea and Mongolia commissioned an army of 300-600 vessels constructed by southern China and Korea to be sailed by 40, 000 men.⁽¹⁾

The First Invasion
The first invasion of Japan by the Mongols in 1274 seized the islands of Tsushima and Ika before continuing on to Hakata Bay on the island of Kyushu. The Mongols, having never encountered the Japanese or the Samurai before, were unfamiliar with the warriors' code of bushidō which dictated a type of one-on-one combat.⁽⁶⁾ Lone samurai were stepping out onto the battlefield to honor this code and were being slaughtered by many Mongols. The Samurai also faced difficulties in cutting through the Mongol's thick leather armor as their katanas would become lodged in it ad break. Bows also proved ineffective as the Mongols wore a layer of silk under their armor which allowed arrows to be pulled out easily. However, fate was on the Samurai's side when a storm blew in which forced the Mongolian landing craft to pull out to open waters. This proved to be a bad move, however, as the fleet was then wiped out by a typhoon, sinking a third of the Yuan ships and drowning 13, 000 men, forcing the Mongols to retreat. ⁽¹⁾

Seven Years of Peace
This invasion was followed by a seven year interlude. The peace was not perfect, however, with both the Mongols and the Japanese sending threats to each other, changing the Japanese with the constant threat of a Mongol incursion. Both sides sought to better arm themselves, which the Mongols massing an even larger fleet ⁽¹⁾ and the Samurai experimenting with modifications to their katanas to better combat the Mongolian armor.⁽⁴⁾ The Japanese also built a a 40km long wall around Hakata Bay which varied in height between 2 and 4.5m tall. Each landowner was assigned a section of varying size depending on the size of their estate.⁽²⁾ The thought of another Mongol invasion was always on the minds of the Japanese and this interlude changed the Samurai to be more adaptable, better warriors, changing the order.

The Second Attack
The Mongols were better prepared for this attack, sending two forces. The first consisted of 900 boats manned by 40 000 men (launched from Korea) while the second force (launched from China) was made up of 3500 ships and 100 000 men. The Japanese countered it with a sizable but outmatched force of 40 000 Samurai and fighting men.⁽⁵⁾ The Korean fleet reached Japan on June 23, 1291 and failed to breach the wall surrounding Hakata Bay. The Chinese fleet, however, were nowhere to be seen. The conflict turned into a fifty day stale-mate, with neither side winning much ground. The Samurai, however, had the advantage, as small groups of warriors would row out to the Mongols' anchored boats under the cover of darkness, kill all enemies aboard and set the boat alight then row back to safety. The Mongol forces began to tire and lose spirit, as many of them were conscripted from nations recently conquered by Khan and had little love for the Emperor. The Mongols soon received an advantage as their main fleet arrived from China on the 12th of August, 1281. However, this was short-lived as on the 15th of August yet another typhoon sunk all but a few hundred of the Mongolian vessels as shown by the painting on the right by Kikuchi Yōsai. By this point, many of the Mongols, including Kublai Khan, began to believe the Japanese were protected by a supernatural force of gods. The Japanese named the typhoons the "divine winds" or kamikaze (神風).⁽¹⁾ This was the first of two times the Japanese had been invaded, the second of which was the Allied occupation of the country during World War II.⁽³⁾

Influence of the Invasions
The Mongol Invasions of the country changed the Japanese and the Samurai to their core. The Samurai were forced to adapt their traditional ways with the Mongols often failing to honor their code of bushidō. The Invasions also changed the way the Samurai fought, switching from using a bow and arrow on horseback to a katana on foot. The katana itself was also changed, going from a straight, thin weapon to a broader, curved blade. It also effected the every day citizens of the country as well, with the residents of Hakata Bay tasked with building the wall which kept the Mongolians at bay during the second attack. They were also faced with the constant fear the Mongols would return at any second.