Relics of the Kamikaze Volume 56 Number 1, January/February 2003
by James P. Delgado

Excavations off Japan's coast are uncovering Kublai Khan's ill-fated invasion fleet.

Stepping off the dock into the warm, murky waters of Imari Bay, I swam to the bottom, then followed a line staked out down a steep slope. The visibility was poor, particularly as excavations had stirred up soft mud, but suddenly I saw the wreck. Unlike other sites I've dived on, the seabed here was not dominated by a large hull. Instead, clusters of timbers and artifacts suggested that a ship, or ships, had crashed into the shore and been ripped apart.

There were bright red leather armor fragments, a pottery bowl decorated with calligraphy, and wood with what seemed like fresh burn marks. My heart started to pound when I swam up to one object and realized it was an intact Mongol helmet. Nearby was a cluster of iron arrow tips and a round ceramic object, a tetsuhau, or bomb. Scholars had doubted whether such bombs, filled with black powder, existed this early, yet here it was. I just floated there, lost in thought that the detritus of this ancient battle lay here as fresh as if the ship had sunk yesterday, not seven centuries ago. The experience brought the story of Kublai Khan's invasions of Japan and the kamikaze--the legendary "divine wind" said to have destroyed his fleets in 1274 and 1281--into the realm of the tangible, touchable past.

Working in this small cove on the shore of Takashima, an island off Japan's Kyushu coast, underwater archaeologists led by Kenzo Hayashida of the Kyushu Okinawa Society for Underwater Archaeology (KOSUWA) have excavated the broken remains of a massive Chinese warship, lost during the khan's invasion of 1281. This past August, I was privileged to join the KOSUWA team as the first Western archaeologist to dive on the site. The fragments of the ship and the artifacts being recovered here--from weapons, provisions, and personal effects to the remains of the crew--are giving the world its first detailed view of a ship from a famous battle that ended when a storm smashed the khan's fleet.

Broken into fragments and scattered by the storm that wrecked it, the ship has already yielded thousands of artifacts, many remarkably well preserved by centuries of burial in silt. As amazing as the artifacts is the ship itself. The hull, made of iron-fastened planks with a large keel that has just started to emerge from the sea floor, had watertight compartments. Although the Japanese archaeologists caution that they have not yet completed excavation of the site, the warship appears to have been about 230 feet in length, twice as big as contemporary European ones. The huge anchor, indicative of the vessel's size, is a massive wood-and-stone assembly weighing more than a ton. Its red oak stock, now broken, was 23 feet long. Analysis of the wood and the granite used in the anchor shows that they originated in China's Fujian Province, site of a major trading port and a marshaling point for the fleet that attacked Japan in 1281. As subjects of the Mongols, China's Sung Dynasty provided most of the fleet--4,400 ships according to Chinese records--and many of the troops for the invasion.

In the 1920s, Japanese archaeologists began excavating remains of a 12.4-mile-long defensive wall built in and around the ancient port of Hakata (modern Fukuoka) in anticipation of the 1281 invasion. These investigations were part of a nationalistic drive to find and restore portions of the wall in order to reinforce the story of Japan's miraculous rescue, thanks to the emperor and his divine ancestors who sent the kamikaze. The story of the invasion and the kamikaze grew in importance to the Japanese government's reinterpretation of its past as the nation prepared for war.

After the end of World War II, archaeological work around Fukuoka occasionally yielded stone anchor stocks thought to be from the Mongol fleets, although Hakata's long history as a port might have accounted for such finds. The possibility of discovering more concrete evidence of the invasions led Torao Mozai, a Tokyo University engineering professor, to Takashima in 1980 to see what might lie on the seabed there. On Mozai's first trip, local fishermen who had trawled the bottom of Imari Bay for generations showed him ceramic pots and other finds brought up in their nets that hinted at a number of shipwrecks. One find piqued Mozai's interest. Discarded in a fisherman's toolbox was a square bronze artifact. Engraved in Chinese and in Phagspa, a written form of Mongolian, it was the personal seal of a Mongol commander. The seal was clear evidence that the fishermen were pulling up relics from Kublai Khan's lost fleets.

Mozai, known as the "father of underwater archaeology" in Japan, used sonar to survey the sea floor. Divers checking promising sonar contacts in 1981 recovered iron swords, stone catapult balls, spearheads, stone hand mills for grinding rice (although some may have been used to prepare gunpowder), and stone anchor stocks. Mozai's finds paved the way for a new generation of Japanese archaeologists to work in the waters off Takashima, among them Kenzo Hayashida.


Since 1991, Hayashida and KOSUWA, which he founded, have conducted annual field seasons at Takashima, surveying the bottom of Imari Bay and performing limited excavations to gauge the number of potential wreck sites and the range of material culture remaining on the seabed after centuries of typhoons and generations of fishermen using dragnets and trawls. In 1994, KOSUWA discovered three wood-and-stone anchors at Kozaki Harbor, a small cove on Takashima's southern coast. The largest anchor was still set, its rope cable stretched toward shore. Buried in mud about 500 feet from the shore and in 70 feet of water, the anchor was a tantalizing clue that a wreck lay nearby. But no massive target appeared in the probes of the surrounding area, just a number of smaller anomalies. Suspecting that this might be a wreck that had broken up, either in 1281 or through the action of typhoons, Hayashida began excavation. In the 1994-1995 season, KOSUWA recovered 135 artifacts near the shoreline, then slowly traced the finds back into deeper water through the 2001 season.

That October, the years of fieldwork paid off with the discovery of the ship's remains. After 20 years of investigation, the waters of Imari Bay finally yielded, albeit in more than one piece, one of the khan's ships. But government-financed construction of a new fish-farming installation directly atop the wreck site was slated to begin shortly. While that project provided funds to KOSUWA's investigations, the 2,600-square-foot site had to be completely excavated by the end of 2002. Work this past year--aided by a large team of divers, underwater communication systems, and an intensive program of excavation in cooperation with the Takashima Museum of Folk History and Culture and the Fukuoka City Museum--proceeded rapidly.

In a series of dives, I was able to watch as the site yielded an incredible array of well-preserved features and artifacts. The main portion of the wreck site lies in 45 feet of water and is buried beneath four feet of thick, viscous mud. Working with a documentation crew, I watched as they mapped each artifact, photographing and then recovering ceramics, tortoiseshell combs, scraps of red leather armor, hull planks, and part of a watertight bulkhead.

The artifacts range from personal effects, such as a small bowl on which was painted the name of its owner, a commander Weng, to provisions and the implements of war. The provisions include a large number of storage jars in various sizes, all of them hastily and crudely made. They hint at the rapid, if not rushed, pace of the khan's mobilization for the invasion. So, too, do the anchor stones. Chinese anchor stones of the period are usually large, well-carved, single stones that were set into the body of the stock to weight the anchor. Those found at Takashima are only roughly finished and made of two stones. More easily and quickly completed than their longer, more finished counterparts, they are not as strong as the single stone anchors. It may be that these hastily fabricated anchors contributed to the fleet's demise in the storm that dashed Kublai's hopes for the conquest of Japan.

The weapons recovered from the site include bundles of iron arrow tips or crossbow bolts, spearheads, and more than 80 swords and sabers. During one dive, I saw a Mongol helmet upright on the bottom, fish swimming in and out of its projecting brow. Close to the helmet was perhaps the most amazing discovery yet made--tetsuhau or ceramic projectile bomb. KOSUWA has recovered six of these from the wreck. They are the world's earliest known exploding projectiles and the earliest direct archaeological evidence of seagoing ordnance.

Chinese alchemists invented gunpowder around A.D. 300, and by 1100 huge paper bombs much like giant firecrackers were being used in battle. Chinese sources refer to catapult-launched exploding projectiles in 1221, but some historians have argued that the references date to later rewritings of the sources. In his recent book In Little Need of Divine Intervention, which analyzes two Japanese scrolls that depict the Mongol invasion, Bowdoin College historian Thomas Conlan suggests that a scene showing a samurai falling from his horse as a bomb explodes over him was a later addition. Conlan's research masterfully refutes many of the traditional myths and commonly held perceptions of the invasion, downplaying the number of ships and troops involved and arguing that it was not the storms but the Japanese defenders ashore, as well as confusion and a lack of coordination, that thwarted the khan's two invasions. But his suggestion that the exploding bomb is an anachronism has now been demolished by solid archaeological evidence. Moreover, when the Japanese x-rayed two intact bombs, they found that one was filled just with gunpowder while the other was packed with gunpowder and more than a dozen square pieces of iron shrapnel intended to cut down the enemy.

The site has yielded fragmentary human remains. A cranium, resting where a body had perhaps been pushed face down into the seabed, and a pelvis, possibly from the same individual, now rest in the conservation lab awaiting analysis. This state-of-the-art lab, at the Takashima Museum of Folk History and Culture, is filled with containers of freshwater in which artifacts rest. Initial study of the artifacts has revealed new information about the khan's forces. Only one percent of the finds can be attributed to a Mongolian origin; the rest are Chinese. The Mongol invasion was Mongol only in name and in the allegiance of the invading sailors and troops.

The future of the finds is uncertain. While the excavation has been fully funded by the Japanese government, it has only committed funding for conservation of ten percent of the collection. For now, the rest will remain in freshwater tanks. The existing museum is too small to house all of the artifacts, and Japan remains firmly gripped by economic recession. Given widespread interest, and the significance of the discovery, perhaps the time has come for an international funding effort to assist the expensive but archaeologically and culturally rewarding work being accomplished there.

Takashima Island's local government is interested in further exploration of the lost fleet of Kublai Khan, and Kenzo Hayashida and his colleagues continue to work off the island's shores. Hayashida believes, like Thomas Conlan and other historians, that the khan's fleet size was exaggerated, and that hundreds, not thousands, of wrecks lie buried here. Even so, the remains now emerging from the mud and water are one of the greatest underwater archaeological discoveries of our time, providing critical new information about Asian seafaring and military technology, as well as an invasion crushed by a legendary storm.


Facing the Khan's Wrath
Kublai Khan's ascendancy to leadership of the Mongols, fraught with internal dissension and civil war, coincided with his long and difficult conquest of China. Needing to obtain additional resources and to demonstrate his power and legitimacy as the Mongol ruler, Kublai, grandson of Genghis Khan, opened a second front in Japan even as he fought the last remnants of China's Sung Dynasty for control of the mainland. The khan sent envoys, demanding the Japanese submit, but the bakufu, Japan's military rulers, rebuffed them. In 1274, with the assistance of his Korean vassal state of Koryo, the khan assembled a fleet that historical accounts suggest was as large as 900 ships to ferry 23,000 troops across the narrow, 110-mile straits of Tsushima, which separate the Korean peninsula from Kyushu. Sailing from Koryo in early October, the fleet overwhelmed Japanese defenders on the islands of Tsushima and Iki before landing at the ancient trading port of Hakata (modern Fukuoka). The Japanese were waiting for them with a force of about 6,000 samurai and gokenin, or armed retainers. Japanese sources suggest that the battle, while hard fought, was going badly for them. The samurai, who fought as individuals, were no match for the Mongols with their tactics of fighting en masse, and their use of poison-dipped arrows and catapult-launched exploding shells. After a week of battle, the Japanese had retreated ten miles inland to Daizafu, the fortified capital of Kyushu. The invaders looted and burned Hakata, but wary of Japanese reinforcements and perhaps the weather on a coast notorious for typhoons, the fleet commanders prepared to withdraw. On October 20, the wind shifted and blew hard. The fleet, with some ships dragging anchor and drifting to shore, departed. Most historical accounts claim as many as 300 ships and 13,500 men were lost in the "storm" that ended the first invasion, but others suggest that the majority of ships simply escaped with the changing wind, with only a handful wrecking on the beach.

Kublai Khan sent more envoys to demand subservience from the Japanese, but the bakufu, emboldened by the retreat from Hakata, continued their defiance, executing the khan's ambassadors. The bakufu also strengthened their defenses, relocating loyal samurai to estates near Hakata and, in 1276, ordering them to build a 12.4-mile-long stone wall along the coast; it was completed in six months' time. The samurai at Hakata organized local fishermen and traders into a coastal naval force of small craft and trained the local inhabitants as a defense force.

The khan and his vassals had not been idle. Chinese histories report that Kublai ordered Koryo to build 900 ships and assemble 10,000 troops for a new invasion. In China, drawing from the newly defeated Sung navy and new ships built expressly for the invasion, Kublai reportedly gathered a force of 3,500 ships and 100,000 troops. Sailing separately in May 1281, the two fleets were supposed to rendezvous at Iki Island in the straits of Tsushima.

But the Korean force, after recapturing Iki from the Japanese, sailed on for Hakata without waiting for the larger Chinese force. The Japanese, alerted by spies, were waiting for them. Thwarted by the stone wall fortifying the beach, the invaders fell back to Shikanoshima Island in the middle of Hakata Bay. Japanese defense craft raided the fleet as it lay at anchor, samurai warriors springing onto the decks of the enemy ships to fight it out with their crews. Other craft were set on fire and sent drifting into the mass of enemy warships. Finally, the Koryo fleet retreated to Iki Island, its role in the invasion over.

The Chinese contingent, after a delay, finally sailed in June and arrived at the small island of Takashima in Imari Bay, 31 miles south of Hakata. Weeks of battle on the small island's shores and hilly countryside were at best a stalemate for the defenders when a sudden storm mauled the fleet on the evening of July 30. According to Japanese records, most of the invading ships were driven ashore and sank, killing nearly all of the 100,000 invaders. At the entrance to Imari Bay, says one Japanese account, "a person could walk across from one point of land to another on a mass of wreckage."

Kublai Khan never again sent a force against Japan. He abruptly canceled plans for a third invasion in 1286. The Japanese embarked on a series of punitive raids against Korea and China, many of them more piratical than naval. If there was a policy, it was found in Japan's ultimate retreat into the solitude and security of their home islands, which they now believed were protected by the gods, who twice had sent winds and storms to thwart an enemy's ambitions. The myth of that protecting force, the kamikaze, would not die until seven centuries later, in the last desperate months of World War II.


James P. Delgado, executive director of the Vancouver Maritime Museum, is author of Lost Warships: An Archaeological Tour of War at Sea (Checkmark, 2001).

© 2003 by the Archaeological Institute of America


By James Delgado on Shipwreck Central/Sea Hunter


James P. Delgado

“Fishermen are usually the first to discover shipwrecks sought by archaeologists. For years, Japanese trawlers operating in the waters off Imari Bay dredged up pottery and other artefacts from the lost Mongol fleet of 1281. In 1980, Torao Mozai, then Professor of Engineering at Tokyo University, used a sonoprobe – a device that geologists use to discover rocks buried in ocean sediment through sound waves – to survey the seabed off Takashima Island. Dr. Mozai followed his first survey with another with a modified sonoprobe, this time with greater sensitivity and a screen that read the results in full colour. Mozai discovered that buried artefacts appeared as different colours on his screen.”

“In 1981, using the new instrument, Professor Mozai’s team pinpointed a number of contacts that divers then recovered. The artefacts recovered from the seabed attest to the diversity of the invading force and its weapons, as well as its need for provisions. In addition to spearheads (from 5 to 30 centimetres long), war helmets, stone balls for catapults, and a cavalry officer’s sword discovered sticking upright out of the mud – exactly where it had been dropped seven hundred years earlier – Mozai’s divers recovered stone hand-mills for grinding gunpowder, iron ingots, stone anchor stocks from the ships, and mortars for pounding rice or corn. The discoveries made international headlines in 1981 (and a National Geographic magazine article) on the seven hundredth anniversary of the second Mongol invasion, and sparked the creation of a new Mongol museum on Takashima Island. The project and the museum’s opening inspired a number of fishermen to donate their own discoveries, including a bronze statue of Buddha, dated to the 12th century, and an amazing find – a bronze seal of authority that belonged to a Mongol commander of a 1,000-man group. Mozai ended his work in 1982, leaving the waters of Imari Bay to a new generation of archaeologists.”

“Since 1991, the Kyushu Okinawa Society for Underwater Archaeology (KOSUWA), under the leadership of Dr. Kenzo Hayashida, has been conducting surveys and excavations off Takashima’s shores.”

“In October 2001, KOSUWA’s hard work paid off with the discovery of the remains of a ship from Kublai Khan’s fleet. The wreck lay in Kozaki Harbour, a small indentation on Takashima’s southern coast and along the shores of Imari Bay. In all the years of work at Takashima, never before had the remains of one of the ships been encountered by archaeologists. In fact, only two other Asian shipwrecks of this age have been found, one at Shinan in Korea and the other at Guangzhou, China. Finding another ship of the period, from a time when Chinese ships were the best examples of shipbuilding in the world, made the discovery at Takashima one of the most significant discoveries in the world of nautical archaeology. What the excavation of the site has revealed in 2002, however, makes it one of the greatest underwater archaeological discoveries of the century. The finds associated with the ship, many of them well preserved through centuries of burial in the mud, are rich and varied.”
“The seabed is covered with thick, viscous, almost gelatinous ooze that the archaeologists have to dig through to get to the layer where the wreck lies. The task of moving all that mud is immense. The area of the site covers 792 square meters of the bottom. The archaeologists are using the handheld underwater suction dredge to vacuum up the mud. They carefully sweep it over the bottom, lying alongside the thick corrugated hose and gently fanning the mud into the dredge with their hands.”

“A grid of metal legs and twine covers the entire site, dividing it into ten-meter square units. I swim up to one unit and see scattered, broken pots and dishes, timbers, and a round object. It is only 14 centimeters in diameter, and yet it is one of the most significant discoveries made to date in the wreck. It is a tetsuhau or an exploding shell. Chinese alchemists invented gunpowder around 300 AD, and by 1100, huge paper bombs, much like giant firecrackers, were used in battle. The first reference to exploding projectiles, thrown by catapults, appears around 1221, when Chinese sources describe hollow shells packed with gunpowder. Some historians have doubted that these shells existed this early, and even recently suggested, in a new book on the Mongol invasion, that the scene in Suenaga’s scroll in which the wounded samurai falls from his horse as a bomb exploded above him, was painted much after the fact because the bombs did not exist then.”

“The discovery of not one, but six of these tetsuhau at Takashima has shown that the old samurai was correct. While four of the tetsuhau are broken, two were intact. X-ray analysis of the two bombs shows one was filled just with gunpowder, while the other was packed with gunpowder and more than dozen one-centimeter thick pieces of iron – shrapnel – to cut down an enemy. They are the world’s oldest exploding projectiles. They date to a century before Europeans first used guns at sea, and centuries before solid stone and iron cannonballs were replaced with shells that exploded on a target. Just a week before our arrival, the discovery of these tetsuhau made national news in Japan. Almost no one in the West has heard about the discovery, and I am hovering over this unique, technologically advanced and deadly weapon from 721 years ago.”

“Another find, resting upright on the seabed, is a Mongol war helmet. Close by, the excavation has yielded small fragments of red leather. The leather is from a suit of lamellar Mongol armour, originally made of laminated strips of leather bound with brass. It is incredible to consider how the mud has preserved these fragile traces by burying them out of the reach of the current. With the armour, as we watch, the dredge gently uncovers a small tortoise shell comb, a fragment of red leather still clinging to one side. I think about another discovery, nearby -- the broken remains of a drowned member of the ship’s complement, perhaps a Mongol warrior. The close proximity of the bones, helmet, armor and arrows again raise the question of whether they all; belong to this victim of the wreck. In the laboratory, just before the dive, I had lifted out the broken skull, found lying face down in the mud, from its box and wondered what stories this victim of a 721-year old shipwreck could tell.”

“Over the next week, we make more dives and watch as more artefacts slowly emerge from the mud. Broken timbers from the ship, including the sockets where a mast would have fit into the bottom of the hull, shattered planks, ceramic bowls and pots once filled with provisions, weapons and armour, and personal possessions, like a small, delicately cast bronze mirror, assert a reality behind the myth and the big sweep of history. The personal items, like the bones, point to more than a lost battle or a lost ship. They remind me of the forgotten people who came here, on the orders of Kublai Khan, to expand an Empire and an Emperor’s prestige, and instead found only death off the shores of a small Japanese island. Their sad story became the stuff of legend, and inspired a myth that died hard with many more wasted lives, as scores of young men deliberately crashed their bomb-laden planes into warships closing in on Japan at the end of the Second World War. As I gaze one last time at the skull in the laboratory, I think of all the victims of 1281. I think of the millions who died in the 1930s and 40s, victims of what was, if not a false legend, then a distorted and exaggerated myth that was used to 700 years later to justify militaristic expansion of a “divine empire” and a brutal war.”

Copyright 2004 © James P. Delgado