The Mongol Emperor of China Kublai Khan‘s first attempt to invade Japan in October 1274, ended prematurely and disastrously. The devastating defeat of an invasion that took over five years to plan would have deterred a less resolute conqueror, but the Great Khan lived fixed in his determination to follow Genghis Khan’s dream to conquer the whole world. He had hoped a victory against Japan would bolster his image as a successful world conqueror, not a Chinese bureaucrat, and give him legitimacy as the Great Khan. He ordered 1,000 new ships to be built in Koryo shipyards to carry troops for his next invasion.
The Japanese, fully alert to the extreme danger of their situation, worked feverishly to prepare for a return visit by the Mongols. They had no illusions about their fate if Kublai Khan’s Mongol army ever established a firm footing on their territory. They erected defensive positions at virtually every principal harbor on the northern side of the islands, including a twenty-kilometer-long stone sea wall along the beaches, they also improved strategic roads and managed to build a small fleet of small coastal craft and fireships with contributions from every Japanese maritime province. Local defense forces were completely reorganized and reinforced with hand-picked draftees who were given newer weapons and a great deal more training.
Six years passed with both sides preparing for what each side believed could be the final struggle. The Japanese saw the battle as a matter of life or death to their independence as a nation. In 1280, with preparations virtually completed, Kublai Khan dispatched a special mission to Japan for one final attempt to settle the matter diplomatically. These new arrivals were captured as they landed and summarily beheaded on the beach. The fatal reception left Kublai Khan with little choice. He would now settle the matter they way he had always settled such matters; with a war. Early in 1281, Kublai Khan set into motion the second invasion of Japan and opened one of the most fateful chapters in East Asian history.
The Mongol expedition to Japan was a vast and complex undertaking that involved not only the logistics of moving men, weapons, horses and materiel to embarkation points in China and on the southern tip of the Korean peninsula, but getting the two separate commands to coordinate their departures and sailing routes so as to arrive together at the intended landing points. Mongol General Hong Da-gu commanded the 30,000-man Eastern Route Army, augmented by 10,000 Koryo fighters under the command of General Kim Bang-gyong. Song Chinese General Fan Wenhu commanded the Southern Route Army comprised of 100,000 mostly former Song Chinese soldiers pressed into Kublai’s service.
The overriding consideration in planning such an invasion involved the weather. Northeasterly monsoons blow from November through March across the East China Sea, making it difficult if not impossible for the bulk of Kublai Khan’s smaller transport ships to tack a course from the south China coast to Japan. June through October marks the typhoon season, a period when violent Pacific storms are possible, particularly in August, and no sailing vessel of the day could survive being caught at sea in such weather.
Time became a critical factor in deciding when to go and delaying the invasion through the summer was out of the question. With the continual threat of violent weather hanging over their heads, two separate armadas comprising the largest overwater invasion force in history set sail for Japan.
The two Mongol armies were due to arrive off Iki Island in the Tsushima Strait sometime in May. General Hong Da-gu was ready for combat operations much sooner than the Southern Route Army, decided to strike Tsushima and Iki islands on his own and without the support of the much larger force sailing from China. The Northern Route Army left Korea in March 1281, with some 50,000 Koryo, Mongol and northern Chinese troops aboard 1,000 ships. The Japanese engaged the Mongols almost immediately after their landings and successfully drove them back into their boats, inflicting heavy losses on the invading troops. General Hong Da-gu witdrew to Masan and remained at anchor until time to sail to the rendezvous with General Bom Mun-ho’s Southern Route Army.
The far larger southern battle group under the command of General Fan Wenhu did not sail until June. General Fan’s 3,500 ships and 100,000 man force finally made the rendezvous with the Koryo command’s 1,000 ships off Iki Island. The massive invading fleet of 4,500 ships set sail directly for the island of Kyushu. The Japanese were already aware of the fact the Great Khan’s army was on the move. The Japanese defense force was on full alert when, on June 23, 1281, lookouts first spotted the line of sails stretching across the entire northern horizon heading directly for Japan.
The Northern Route Army, carrying Kublai Khan’s spearheading strike force, entered Hakata Bay and anchored bow-to-stern close to the shoreline along the Shiga Peninsula. Chained together for mutual security, crews laid planking between ships to enable troops to rapidly respond to any attempted boarding of any ship by the Japanese. Ships equipped with catapults began bombarding the beach defenses with heavy rocks while Mongol cavalry and infantry went ashore at an unfortified beach to assault Japanese defensive positions. Fighting on their home ground, the Japanese suffered heavy losses as they stubbornly resisted the attack.
General Fan Wenhu took his southern command into Imari Bay, a good harbor about thirty miles further west, where defenses were weaker and he anticipated an easy advance inland. After putting his entire 100,000 man army ashore, General Fan began his eastward advance through high broken terrain. The Mongols ran headlong into a large Japanese field army and became entangled in a series of desperate battles in the hills. After days of fierce fighting the advance stalled. Meanwhile, Japan’s small flotilla of ships managed to cut out or set fire to many of General Fan’s transport ships lying exposed in Imari Bay.
The Japanese fiercely defended their territory and managed to hold Mongol gains to little more than the beachheads at each of their landing points. The Mongols had no success in turning or even breaching the Japanese defensive lines. Desperate fighting continued through July as the Mongols vainly tried to breakout of their coastal positions. With no hope for reinforcements, the Mongols began to realize they had insufficient troops to take Japan.
Both commands had suffered heavy casualties and supplies were running low with no hope of resupply. Such was the state of affairs into mid-August, the height of the typhoon season in the area of southern Japan. Koryo sailors in Hakata Bay had every reason to expect the arrival of at least one of these great storms during the campaign and Mongol commanders totally ignored every warning that any insolent ship captain had to offer. On the afternoon of August 15, 1281, a major typhoon roared through the southern Japanese islands and caught the invaders in precisely the same predicament that had been foretold by comparable circumstances in 1274. At the urging of the Koryo naval captains, particularly those anchored at the northern end of the line along the Shiga Peninsula, many of Koryo’s troops scrambled back aboard ship. Although they sailed before the height of the storm reached the area, the approaching typhoon overran and sank many ships after they reached the open sea.
The Chinese ships under General Fan, crowded at anchor in Imari Bay, took the full fury of the storm. In their panic to get underway, most of the soldiers who managed to get aboard the ships drowned as ships collided and sank while trying to clear the narrow neck of the harbor. The blackened skies, driving rains, mountainous seas, and roaring wind provided a backdrop to the deafening sounds of colliding ships, snapping cables and masts, and the screams of terrified men caught in a deadly display of nature’s fury. Many of the ships that managed to reach open water were subsequently blown onto the rocks. Although the admirals and generals escaped with their capital ships, only a small remnant of the gigantic armada ever returned to the mainland.
The sudden Mongol retreat abandoned thousands of soldiers on the beaches cut off from supplies and reinforcements. The Japanese were quick to take full advantage of the situation. Abandoning their defensive positions, they furiously attacked the stranded survivors on the beaches and executed them en masse. From August 16, 1281, until the Japanese surrender on August 15, 1945, no invading soldier ever again set foot on the Japanese islands.
To the Japanese, the heaven-sent storm and the manner in which the Mongols had been repulsed reconfirmed their belief in their own divine origins. From that deadly August afternoon in 1281 down to the present time, the “divine wind” that destroyed the Mongol invasions of Japan has been known by its more popular name, kamikaze.
The 1281 defeat broke Kublai Khan’s image of invincibility, and when he tried to re-establish it by campaigns into Southeast Asia, he failed there as well.