The Empire of Blue Mongolia (Yuan) with the capital in Daidu (modern Beijing) was founded by Chinggis Khan’s grandson Khubilai in 1260 on the conquered territories of China and East Asia. He proclaimed himself Khan of Yuan Dynasty. After Korea recognized the suzerainty of his empire, Khubilai Khan wanted to conquer Japan make it part of the Yuan Empire.
In 1266, Khubilai khan sent messengers to Japan with the following letter: “Anointed by the sky, the Great Mongol emperor sends a letter to the ruler of Japan. The sovereigns of small countries, which have a border along the coast, always tries to maintain friendly relations.
Since my ancestor received heavenly power, countless principalities of Korea sought to challenge our superiority, and now they thank for the ceasefire and for the rebirth of their country, which began with my ascent to the throne. We are like father and son. We think you already know this. Korea is my eastern possessions.
Japan was in alliance with Korea and, sometimes with China, since the founding of your country; however Japan has not sent ambassadors since I took the throne. This is extremely frustrating. Therefore, we are sending a letter expresses our desires. We should get in touch as friends. We believe that all countries belong to one family. No one wants to raise arms”.
In the same letter, Khubilai Khan warned the Japanese King that if he disagrees, he would declare war and invade Japan by force. It is interesting that this letter has survived to our days and is kept in the temple of Todai-chi in Nara city, Japan.
Emperor Kameyama who had no real power in Japan, as well as the most influential shoguns decided not to respond to the letter. The Japanese leadership also ignored the later letters of Khubilai Khan in 1269, 1269, 1271 and 1272. After that, Khubilai decided to immediately capture Japan.
Mongol troops, who for 30 years successfully fought in the internal waters of China, have accumulated some experience in the battles on the water. But they never fought on the open seas.
At the headquarters of Khubilai Khan’s army, they decided to construct the first fleet to combining the technologies of Korean combat light marine vessels and Chinese heavy-duty river merchant vessels.
After doing all necessary preparations in November 1274, a fleet of up to 900 ships left the Korean port of Happo (modern Busan) and sailed to Japan. The ships had about 25,000 soldiers (mostly ethnic Chinese and Koreans, except for the Mongol officers).
On the way, after taking over Tsushima and Iki islands, on November 19 the fleet landed in Hakata Bay, not far from Dazaifu, the ancient administrative center of Japanese main island Kyushu. The next day, the Battle of Bunya, also known as the Battle of Hakata Bay, took place.
The landing forces of Khubilai Khan, using the powder bombs unprecedented for the Japanese, began to easily gain the upper hand.
Around midnight, a terrible storm forced the Mongol commanders to order the troops to hastily board the ships and enter the open sea. But more than half of the ships were smashed on the shore. Since the storm did not subside, the surviving ships had to return to the shores of Korea.
After the failure of the first attempt to capture Japan, Khubilai Khan sent again messengers to Japan ordering them not to return unless they get an answer in September, 1275.
Five young messengers that were led by an young, fearless and skillful diplomat – the Mongol Tuushin, headed Japan. But the most influential shogun of Japan, Hozyo Tokimune, ordered to decapitate the messengers. Before execution Tuuschin, without fear of death, proudly said in verse that killing Great Khan’s messengers no one in this world can overpower the Yuan Empire. The enraptured Japanese immortalized his words by carving them on the stone in the place of his execution near the temple of Joritsuji in the city of Fujisawa.
In 1279, five more emissaries of Khubilai Khan were again decapitated, this time in Hakata. In anticipation of the next invasion, the imperial court of Japan ordered all the temples to pray for victory over the Yuan dynasty’s fleet.
Beginning in 1275, the Kamakura shogun Hozyo Tokimune began actively to take measures to protect the country from an attack. Also they increased discipline in the ranks of samurai in Kyushu and the rulers ordered the construction of forts and a large stone wall and other defensive structures in places of possible landing, such as Hakata Bay, where a two-meter wall was erected in 1276.
In the spring of 1281, the Mongols sent two independent fleets to conquer Japan. One is impressive in 900 ships, with 40,000 Korean, Chinese and Mongol soldiers on board, coming from Korean peninsula, and the second with an even more impressive fleet of 3,500 ships with 100,000 soldiers left from the south of China.
The capture plan was to have a coordinated attack by the combined fleet. But the Chinese fleet was delayed because of the difficulties with the provisions and the manning of a huge number of soldiers. The Korean fleet went on a voyage first, but returned without being able to capture the island of Tsushima.
In the summer, the united fleet took Iki Island and moved to Kyushu, with stops on the passing islands. The Mongol forces were thrown back to the ships. The shore was well fortified, so the defense was not particularly difficult. Japanese troops inflicted solid damage to the united fleet. Disorganization brought disagreement in the plans and discord of the three main commanders. According to some reports, Chinese troops did not sympathize with the invasion and were not eager to fight.
The typhoon suddenly appeared in mid-August. In a few hours typhoon came into full force. Some of the ships left, fleeing from the typhoon, but most of them were broken, parts were scattered throughout sea. Today it is believed that the destruction of the Mongol fleet was provoked by another factor. Most of the ships were built in a hurry in punt and were flat-bottomed. Ships of this type (unlike ocean keel vessels, which are more difficult to roll over) are difficult to use in the open sea, and they were left to the hurricane.
Only a small fraction of Kublai Khan’s original force returned home from this ill-fated expedition, one of the largest and most disastrous attempts at a naval invasion in history.
Nevertheless, Khubilai Khan did not abandon the plan to seize Japan. But his plans were not meant to become a reality. In the Mongolian steppes, discontent grew with his policy which turned Mongolia into an abandoned province. His struggle with the influential Khan Khaidu Khan turned into a long-term civil war and he was already not up to the Japanese islands.
It was the largest attempted naval invasion in history which scale was only recently eclipsed in modern times by the D-Day invasion of allied forces into Normandy in 1944 during World War II.
In popular Japanese myths at the time, the god Raijin was the god who turned the storms against the Mongols. The storm was named kamikaze literally “divine wind”.
The name given to the storm, kamikaze, was later used during World War II as nationalist propaganda for suicide attacks by Japanese pilots. The metaphor meant that the pilots were to be the “Divine Wind” that would again sweep the enemy from the seas. This use of kamikaze has come to be the common meaning of the word in English.