Zheng He's Voyages of Discovery

Photo for Zheng He

Noted oceanic scientist Jin Wu discusses the 15th century expeditions of the Chinese mariner Zheng He & the celebration of the 600th anniversary of his first voyage

What Zheng He accomplished, Jin Wu declared, must be considered an achievement for all of mankind, not just a Chinese achievement.

On April 12 Jin Wu, distinguished oceanic scientist and former Minister of Education of the Republic of China (on Taiwan), discussed Zheng He's voyages of discovery and the upcoming celebrations of the 600th anniversary of his first voyage.

In his talk, Professor Wu emphasized that, especially since the documentary record surrounding Zheng He (sometimes written Cheng Ho; 1371-1435) and his voyages is so thin, oceanic scientists and engineers and other physical scientists can provide important insights to supplement the work of historians.

Historical Background

Professor Wu began by briefly retracing the history of Zheng He's voyages. Upon the orders of the emperor Yongle and his successor, Xuande, Zheng He commanded seven expeditions, the first in the year 1405 and the last in 1430, which sailed from China to the west, reaching as far as the Cape of Good Hope. The object of the voyages was to display the glory and might of the Chinese Ming dynasty and to collect tribute from the "barbarians from beyond the seas." Merchants also accompanied Zheng's voyages, Wu explained, bringing with them silks and porcelain to trade for foreign luxuries such as spices and jewels and tropical woods.

These voyages, Professor Wu noted, came a few decades before most of the famous European voyages of discovery known to all Western school children: Christopher Columbus, in 1492; Vasco da Gama, in 1498; and Ferdinand Magellan, in 1521. However, Zheng He's fleets were incomparable larger. According to figures presented by Professor Wu:


Number of Ships

Number of Crew

Zheng He (1405 - 1433)
48 to 317
Columbus (1492)
Da Gama (1498)
ca. 160
Magellan (1521)

Moreover, Zheng He's ships, Professor Wu explained, were impressive examples of naval engineering. His so-called treasure ships (which brought back to China such things a giraffes from Africa) were 400 feet long. Columbus's flagship the St. Maria, in contrast, was but 85 feet in length. Zheng He's treasure ships, Professor Wu mentioned, displaced no less than 10,000 tons and had an aspect ratio (width:length) of 0.254; in other words, they were wide and bulky—"the supertankers of their day." Aside from the treasure ships, Zheng He's fleet also contained a variety of other, specialized vessels: "equine ships" (for carrying horses), warships, supply ships, and water tankers.


Check out an animated reconstruction of Zheng He's treasure ship, from the TV series Nova, (external link).

Professor Wu invited the audience to imagine the scene of Zheng He's 300-vessel fleet on the sea, spread out over many square miles. ("Sailing ships," Wu pointed out, "require room to maneuver" and thus the fleet would have blanketed a wide swath of the ocean.) If an object of the voyages was to display the glory and might of China, then there can be no question but that this magnificent fleet would have awed all who witnessed it. It is ironic, then, that today little is known of Zheng He's voyages. This is, Wu pointed out, mainly the doing of the Confucianists in the imperial court, who saw to it that Zheng's ships were burned after his last voyage and who made every effort to "systematically destroy all official records of the voyages." Their motives were purely political. During much of the Ming dynasty (1368 – 1644), the eunuchs exercised great power in the imperial court, at the expense of the Confucian civil bureaucracy. The expeditions of Zheng He, who was himself a eunuch, were strongly supported by eunuchs in the court and bitterly opposed by the Confucian scholar bureaucrats.

The Research Agenda

Although the Chinese documentary record of Zheng He's voyages is thus woefully incomplete, Professor Wu hopes that relevant documents may exist in the places Zheng He visited. He encourages historians in these places to comb through archives and other sources in search of such records.

Archaeology also, Professor Wu stated, is likely to uncover valuable evidence. For instance, the shipyard in Nanjing where Zheng He's vessels were constructed still exists; or rather, the channels in which the ships were built still exist. The shipyard evidently had five channels during Zheng He's time, but two of the five have been filled in. When Wu visited the disused shipyard in 2002, he was told the remaining three channels were to be filled in. He quickly lobbied the relevant government officials and had the channels saved. Indeed, the channels will now become part of a naval museum. It is likely, Wu pointed out, that important artifacts are preserved the oxygen-starved mud of the channels.

Wu stated that "many scientific and technological aspects of the expeditions are worthy of multidisciplinary studies, which may in turn stimulate further historical studies." In other words, "engineers and scientists should work together with historians."

Professor Wu himself is organizing three projects:

  1. shipbuilding technology in ancient China,
  2. navigation technology in ancient China, and
  3. management science in ancient China.

Zheng_He2Regarding shipbuilding technology, Wu pointed out among other things that a ship traversing the ocean sustains many forces: it is "not just like a matchbox in a swimming pool." It is still not known how it was possible for Chinese shipwrights to build a framework, without any iron, that could sustain a 400-foot long vessel. Instead of looking for the answer just in the documentary record, Wu proposes that "naval architects join in with historians to discover whether it was possible, or how the ships were built."

About navigation technology, among the topics Wu discussed was how scientists today, using oceanic microwave remote sensing executed via instruments on satellites, can ascertain the "distribution of waves, of currents, of winds, of water temperature, of water depth" on a weekly basis. "Ocean-going sailing ships sailed mainly by wind and ocean currents. With the combined effort of historians, navigators, and oceanographers, Zheng He's expedition routes can be more convincingly verified." Using computer simulation, "we can put a ship somewhere and see where it goes."

Wu stated that in China (and in Taiwan), it is always assumed that "management science is an import from the West." However, in Wu's view, Zheng He's expeditions involved highly sophisticated techniques of organization and planning; in other words, management science. For instance, Wu mentioned that transferring supplies to ships on the high seas is still difficult, yet somehow Zheng He's fleet was able to transfer water from the water tankers to the other ships. This is, Wu observed, "really amazing."

Zheng He's expeditions involved, among others:

  • Building ships
  • Recruiting and training of crew members and soldiers
  • Acquisition of domestic goods for exchange
  • Command and logistics on the high seas

Sailing a large fleet sailing into largely unknown waters "required advanced management skills and systems and certainly deserves our intensive study." There was no margin for error. "What was achieved was comparable to what we did in our day to go to the moon."

Celebration of the 600th anniversary of Zheng He's First Voyage

What Zheng He accomplished, Jin Wu declared, must be considered an achievement for all of mankind, not just a Chinese achievement. Moreover, it presents an opportunity, Wu continued, "for both sides of the Taiwan Strait to work together."

Professor Wu went on to list his many activities in promoting the study of Zheng He and his voyages, including delivering the keynote speech (on Zheng He) at the annual meeting of the Conference on Asian Seas, in March 2001; organizing the First International Conference on Zheng He, held in Taipei, in September 2001; the establishment of Zheng He study clubs in several cities in the United States; and others, including plans to build a replica of Zheng He's treasure ship. The first iteration will be only 180 feet in length because "we don't have confidence we can build a 400-foot ship -- and we don't have that much money! Furthermore, there is quite a debate about what kind of ships Zheng He really had: the shape, etc." This first ship will thus not be a replica, but will incorporate features of Zheng He's ships about which there is reasonable certainty. As knowledge expands, more ships will be built, each iteration being closer to the ships that Zheng He sailed.

Comments of Richard von Glahn

At the conclusion of Jin Wu's talk, Richard von Glahn (UCLA Professor of History, and a specialist in Chinese history) offered some comments. First, von Glahn mentioned that he teaches world history, and that all world history texts mention Zheng He. The problem with these texts, von Glahn continued, is with the presentation. The tendency is to offer counterfactual arguments; in other words, to emphasize "China's missed opportunity." The "narrative emphasizes the failure" and pays insufficient attention to what was accomplished.

In a word, von Glahn continued, "Zheng He reshaped Asia." Maritime history in the fifteenth century is essentially the Zheng He story and the effects of Zheng He's voyages. For instance, Malacca, on the Malayan peninsula, and Zheng He's most important port after those in China, in the fifteenth century became the great port and hub of a trading network that extended across Southeast Asia and up to China.

Von Glahn emphasized that Zheng He's influence lasted beyond his age. Zheng He, von Glahn suggested, may be seen as the tip of an iceberg: He was prominent, but there is much, much more to story of maritime trade and other relationships in Asia in the fifteenth century and beyond. The conferences that Professor Jin Wu is planning in conjunction with the 600th anniversary of Zheng He's first voyage will, von Glahn stated, show this.

Jin Wu (Ph.D. in Mechanics and Hydraulics, University of Iowa), an internationally renowned researcher in oceanic science, was the Minister of Education in the Republic of China on Taiwan from 1996 to 1998. He is a member of both the U.S. National Academy of Engineering and the Academia Sinica. He is currently Distinguished Professor of Hydraulic and Ocean Engineering, National Cheng Kung University (in Tainan, Taiwan), and concurrently Director of the Water Resources Research Center, and Director of the Research Institute for Public Affairs, both at Cheng Kung University. Dr. Wu was for many years a professor of marine studies at the University of Delaware, one of the world's foremost centers for marine and oceanic studies. He is now H. Fletcher Brown Professor Emeritus of Marine Studies and Civil Engineering, University of Delaware.

Links to resources on Zheng He

Reviews of Menzies' book, 1421

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Published: Tuesday, April 20, 2004