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The Koryo-Mongol allied invasion of Japan
The myth of kamikaze
Lee Wha Rang
6/9/2004



Photo: Kublai Khan, the First Emperor of Yuan and a grandson of Genghis Khan, (left) and a contemporary painting of the Khan and his wife (center) on a hunting party. Kublai had no training or expertise in military affairs.

Allied armies of Koryo and Kublai Khan invaded Japan in 1274 and 1281. Both invasions failed at the hand of Mother Nature. The sword wielding samurais of Japan were no match for the invaders, who were armed with gun-powder canons and superior fighting tactics. The invaders succeeded in landing on Kyushu after occupying Tsushima and other nearby islands. But gathering storms forced the invaders to pack up and leave.

After conquering much of China, Kublai Khan sent armies to conquer Koryo but they were driven out time and again, and after a decade of constant war with the Mongols, Koryo gave up and became a vassal state of the Mongols. Koryo's King Kojong sent his crown prince to the Khan's court as a hostage.

When Kojong died in 1274, the Khan gave one of his many daughters to the prince as his wife and sent him home as the 25th king, Chung-ryol, of Koryo. The Mongol princess brought with her an army of Mongol attendants, cooks, and guards, and turned the Koryo court into a virtual Mongol home away from home.

Kublai Khan's interest in Japan was aroused in 1265 when Cho Yi, a Koryo courtesan, informed him that Japan could be subdued easily. In the following year, Kublai sent two emissaries He De and Yin Hong to Koryo and asked King Kojong to facilitate their entry to Japan. They were unable to meet any Japanese officials and returned home empty-handed. The Khan's attempt to subdue the Japanese peacefully failed and he decided to use brute force to subdue Japan.

Kublai asked Koryo to provide ships, sailors, soldiers and provisions, and so, Koryo mobilized some 30,000 carpenters and built about 300 large ships. In October 1274, a Mongol army of 20,000 commanded by Hol Don came to Koryo. The Mongol army was joined by a Koryo army of 5,000 commanded by Kim Bang-gyong. The allied army left Masan in an armada of 900 ships manned by 6,700 Koryo sailors on 3 October, 1274.

Two days later, the Koryo army stormed Tsushima and occupied the island and the Mongols occupied Iki island. On October 14th, the allied forces occupied Hirado and then moved on to Hakata Bay. Japanese forces suffered heavy losses and retreated inland to defend Dazaifu.

On October 21st, the allied forces returned to their ships for re-supply and rest. But a storm suddenly came upon the invasion fleet and the invaders gave up their operations and returned to Masan.

Undaunted by this failure, Kublai sent another 'peace' delegation to Koryo in 1275, asking the king to deliver a message to the Japanese shogun. The king sent Suh Chan to Japan with the letter from Kublai but the Japanese executed Suh and sent back his severed head. The Khan was enraged and ordered another invasion of Japan.

The Mongols built a fortress near Masan and stationed a large garrison army there, and Cheju-do was turned into a vast pasture for Mongol army horses. The Japanese Shogun knew of the invasion plan and mobilized forces to defend Japan. Stone fences were build along the coast and the populace was armed.

In 1281, the Khan formed two mighty armies: the Eastern Route Army of 30,000 led by Hong Da-gu, a Mongol general, augmented by a Koryo army of 10,000 commanded by Kim Bang-gyong and the Southern Route Army of 100,000 led by Bom Mun-ho, a Chinese general. Bom's army was mostly former Sung Chinese soldiers pressed into Kublai's service.

The Eastern Route Army, in 900 Koryo ships, departed from Masan on 3 May and occupied Tsushima, and proceeded to occupy nearby islands. On June 6, it attacked Hakata but was driven back and landed at Shiganoshima. Several days later, the army was driven back from Shiganoshima and returned to Iki and then to Hirado.

The Southern Route Army of General Bom arrived in 3,500 Chinese ships in mid-July, and the combined forces began to push back the outnumbered defenders. By the end of July, the invaders were victorious and well on the way to occupying Kyushu. Then a severe storm kicked up on July 29 and some Mongol generals panicked and sailed to the safety of Masan: nearly half of the invasion fleet left the battle area. To make the matter worse, an epidemic spread among the soldiers, killing several thousands.

On August 1, another storm kicked up forcing most of the remaining ships to return to Masan leaving behind a token army of about 20,000 soldiers. The Japanese descended on the outnumbered invaders and killed all but about 10,000 Chinese soldiers. Of the 9,960 Koryo army and 15,029 sailors, 19,397 Koreans made it back home. The Mongol generals and army, fearing severe punishment by Kublai, went into hiding in Koryo. The Chinese captives became slaves in Japan and few of them made it back to China. It has been claimed that many of the Chinese defected and that some officers sabotaged the Mongol ships and canons.

Kublai wanted another invasion and asked Koryo to build more ships and stock up army provisions. But a major rebellion delayed him and the plan was dropped when Kublai died.

Japanese history books claim that a Buddhist monk Il Yun saw the invasion fleet and began to chant. As he kept up his chant, winds became stronger and stronger, and soon, the waves began to dance wildly rocking the enemy ships. Eventually the ships began to break up and sink. Thus the myth of kamikaze was borne. The Mongols slaughtered, as in other Mongol campaigns, tens of thousands of Japanese, including women and children.

Contrary to the claims made by Japanese historians, the Koryo-Mongol invaders lost no more than about 10-15% of the men and ships. The Mongol and Koryo commanders knew of the oncoming storms and returned the armada to Koryo ports mostly intact. The Japanese claims are inconsistent with Koryo and Mongol archives - and most importantly with archeological evidence: only few shipwrecks and other footprints of the failed invasions have been discovered. It is true that the 'divine' winds drove the invaders away but the winds did not wipe out the mighty armada.


Lee Wha Rang's article is featured on Korea WebWeekly.

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