Khubilai Khan ordered naval attack on Cambodia. most likely under the reign of King Jayavarman VIII ... but it failed

Kublai Khan, the grandson of Genghis Khan

Khubilai Khan’s Lost Fleet : History’s Greatest Naval Disaster
by James P Delgado 240pp, Bodley Head, £15.99

The divine wind blows out

Kevin Rushby discovers the real reasons for Khubilai Khan's failure to invade Japan

Saturday 28 March 2009
Kevin Rushby
The Guardian

In 1974 a Japanese fisherman called Kuniichi Mukae was digging for clams on the small island of Takashima when his spade hit something hard in the sand. Pulling the object out, Mukae saw it was a small piece of bronze. He gave it a wash and tossed it into his toolbox, where it lay forgotten. What the fisherman did not know was that he had just uncovered the key to two of the most significant events in Japanese history: the failed naval invasions of 1274 and 1281 by, of all people, the Mongols – a warrior race not usually associated with armadas.

As James Delgado points out in his engaging and highly readable account of those attacks, the legends that grew up around them had a huge impact on the development of a Japanese national psyche. Both fleets were despatched by Khubilai Khan and defeated, not apparently by the outnumbered samurai waiting on the beaches, but by storms that were later recast as kamikaze, divine winds, sent by the gods as proof of their special favour. This belief in divine favouritism would have remarkable consequences centuries later, but the immediate effect of the attempted invasions was to drive a wedge between Japan and her neighbours that had not previously existed. By the 17th century this had become so severe that Japan isolated itself from the rest of the world for more than 200 years. Even when the nation emerged from self-imposed house arrest in the 1850s, its militaristic assertiveness would feed on the legend of hostile neighbours eager to invade.

Delgado writes with an attractively direct style, but it takes some time to get to his main story: the marine archaeological discoveries of recent years. He starts by recounting the growth of the Mongol empire, from the perspective of China and the far east. This is helpful: our images of the Mongols are so much bound to the ideas of horsemen rolling westwards that we forget that Khubilai Khan was the ruler of a sophisticated and diverse society. In capturing the Song dynasty lands of central and southern China, he had become the world's greatest, and richest, emperor. His subjects traded far and wide, their ships far exceeding European vessels of the time, in both size and technological development. Within China goods were carried along the Grand Canal, a 200ft-wide channel that ran for 2,100 miles and connected a further 30,000 miles of waterways. Significantly, the emperor also inherited a powerful navy with ships capable of firing porcelain shells packed with gunpowder and nails. When the outlying islands of Japan refused to kowtow to him, Khubilai ordered a mammoth invasion designed to crush them into submission.

The first foray went well to begin with, but the invaders faltered when they reached the third island and were finally driven away by a storm. When a second, far larger, fleet arrived seven years later, the samurai fought valiantly but without any real hope of victory. Their resistance held the attackers long enough, however, for a storm to come to Japan's rescue again, sinking hundreds of anchored vessels and drowning thousands of troops. Those already ashore were captured and beheaded. This second defeat was a huge blow to Khubilai Khan. Not only that, but the myth of Mongol invincibility had sunk with his ships and Khubilai's Yuan dynasty would prove to be one of the shortest in Chinese history.

At this point Delgado's story starts to motor – you can tell that his real enthusiasm is for jumping into a wetsuit and diving under the waves to see for himself. His guide in this is a marine engineer called Torao Mozai who in 1978 decided to spend his retirement investigating the truth behind Japan's legendary rescue by the "divine wind". As a second world war veteran who had served with men who became kamikaze pilots, he well knew the power of the myth; what astonished him was the lack of firm evidence. Underwater archaeology was completely unknown in Japan, but Mozai persisted, and his tenacity drew rewards. Hearing of the archaeological work being carried out near his home, Kuniichi Mukae went to his tool kit and dug out the piece of bronze that he had unearthed a few years before.

The artefact was soon recognised as a bronze seal dating from 1277 and once the property of a Mongol army commander. Mozai was now certain he could locate the lost fleet. Bringing in expertise from the US, he started excavations. Over the seasons, the finds grew more and more exciting. One site even yielded up the armour, personal possessions and partial skeleton of "Commander Wang", one of Khubilai's officers. Careful analysis of the ships' woodwork suggested that the fleet may have been in such poor condition that it was vulnerable to any bad weather. Haste and inexperience had scuppered the Mongol plans, and the "divine wind" seems, at best, an imaginative exaggeration.

I would have liked more of this, but Delgado is soon back into the history books, teasing out the repercussions of the failed invasions for our modern world. The Yuan navy was certainly weakened, but perhaps the disappearance of Mongol invincibility was most significant. Khubilai never tried to return to Japan, but ordered further attacks on Vietnam, Cambodia and Java. All failed. In Vietnam the military leader Tran Hung Dao used his experiences fighting the invaders to write a definitive treatise on guerrilla warfare – a text that, almost 700 years later, inspired General Giáp in his battles against the French and later the Americans. No doubt, had Khubilai Khan captured Japan he would have gone on to expand the Chinese empire throughout south-east Asia and our modern world map might have looked very different indeed.

With interest in China and its history at an all-time high, we've seen everything from John Keay's scholarly overview, China, to more popular accounts such as Gavin Menzies's 1421. This trim volume, covering only a small part of a vast subject, is nevertheless a valuable addition to the shelves.

• Kevin Rushby's Paradise: A History of the Idea that Rules the World is published by Robinson