Water: The Epic Struggle for Wealth, Power, and Civilization - Steven Solomon (2010)

Part I. Water in Ancient History

Chapter 5. The Grand Canal and the Flourishing of Chinese Civilization

Although intensive irrigation society developed latest in China among the river-born, cradle civilizations of antiquity, its water management achievements surpassed all the others. China’s inventive, adaptable, and wide-ranging water engineering responses to its diverse environments was the foundation of what became the most precocious, preindustrial civilization in world history. “The Chinese people have been outstanding among the nations of the world in their control and use of water,” observed Joseph Needham in his classic Science and Civilisation in China.

China’s ancient civilization arose in a landscape markedly different from other hydraulic societies. It began in the semiarid inland north where the Yellow River in its middle reaches exited the barren steppe highlands of Mongolia and carved a large bend through plateaus covered with deep deposits of soft, flakey, yellowish rich soil, called loess, left by the receding ice age. The climate on these stark plateaus, larger than the size of California, was harsh: frigid in winter, scorching hot in summer, prone to droughts, dusty whirlwinds, and occasional summer downpours that eroded the soft cliffs and washed its loess soil into the Yellow, choking it with the thick silt that gave the river its name and enriching the north China floodplain into which it spilled. Yet the plateau’s combination of ample river water, easily farmed and drained soils, and military defensibility provided fertile conditions for a single season of intensive, field grain agriculture. The best adapted crop was millet, a tough grain capable of surviving prolonged dry periods. Gradually, farming was extended throughout the large, loess-enriched, northern floodplains. Most extraordinarily, however, China’s civilization achieved the rare accomplishment of hurdling its geographic origins over time to transplant itself far beyond its mother river region to a radically different habitat south of the 33rd parallel dominated by the voluminous Yangtze River. In contrast to the semiarid north, the Yangtze region was rainy, humid, verdant, mostly hilly, heavily monsoonal, and civilized by the intensive cultivation of an entirely different crop, wet rice.

The outstanding, transformational event that catapulted Chinese civilization above all its contemporaries, and marked one of water history’s turning points, was the completion in the early seventh century AD of the Grand Canal—still mankind’s longest artificial waterway, extending over a distance equal to that between New York and Florida. The south-north-running canal linked China’s two disparate, giant river systems and habitats to create the world’s largest inland waterway transportation network. Just as the Nile had unified Upper and Lower Egypt, China became integrated into a militarily defensible nation-state with a strong, centralized government that commanded an expansive diversity of highly productive economic resources. The Grand Canal played a catalytic role not only in China’s becoming the world’s most precocious civilization during the Middle Ages but also in the country’s fateful fifteenth-century decision to turn its back on the rest of the world that ultimately led to its prolonged, slow decline.

The Grand Canal was so successful because it bridged China’s underlying hydrological fault line: north China’s chronic insufficiency of accessible freshwater resources to fully irrigate its superabundance of rich soil to achieve its maximum food-growing potential, and south China’s opposite profile of having more water than could be productively employed on its less fertile soils. Managing this north-south water and land resource mismatch has been a recurring, central technical and political challenge of Chinese governance in every era since imperial times.

Both the 3,400-mile-long Yellow and the 3,915-mile-long Yangtze originated in the Tibetan plateau in the Himalayas. Beyond that their signature flows and environmental characteristics diverged sharply. The Yellow was shallow and by far the world’s siltiest river—30 times siltier than the Nile and nearly three times more than the famously muddy Colorado River. A dipperful of its water was commonly said to contain 70 percent mud. It was the rapid buildup of eroded silt from the loess plateaus that caused the Yellow to frequently overflow its banks in unpredictable, devastating floods across its lower plains. So many millions perished and lost their livelihoods in these fearsome floods over the centuries that the river became known as “China’s Sorrow.” Its greatest floods—some carving new paths as far as 500 miles away to the Yellow Sea—repeatedly fomented political and economic upheavals throughout Chinese history. Building tens of thousands of miles of levees to try to contain the Yellow within its banks, and rebuilding them after the inevitable failures, was thus always a top political priority of every Chinese dynasty.

The huge Yangtze, by contrast, carried some 15 times more water than the Yellow, with deep navigable channels and many large tributaries that made it an ideal transport highway for large vessels once its waters had descended the mountains and wound its way through its deep canyons and gorges to enter its enormous lower basin and swampy delta. The Yangtze’s seasonal monsoon floods regularly inundated the region; every half century or so, however, the combined rush of descending water and the engorged flow from its tributaries created giant waves that overwhelmed all man-made flood control infrastructure and resulted in devastating floods. When China’s climate was moister in ancient times, the central section of the Yangtze had been a gigantic swamp, far too wet to sustain large-scale civilized human settlement. Gradual desiccation, and Chinese advances in water redirection, terracing, drainage, and other wet rice irrigation techniques gradually transformed the region into prosperous farmland. By medieval times it was producing the greater part of China’s food, with rice surpluses distributed along its extensive tributary network and to the Yellow River region in the north via the Grand Canal and coastal sea routes. Political control of the “golden waterway” of the Yangtze thus joined flood control as a vital linchpin of Chinese power. So closely correlated was river management and governing power that the very Chinese character for “politics” is derived from root words meaning flood control.


The Silk Roads


The traditional founding father of China’s Yellow River civilization was Yu the Great. A water engineer, Yu rose to power on the merits of his accomplishment as the tamer of the great floods that ravaged settled life in the Yellow basin before recorded history. By having “mastered the waters and caused them to flow in great channels,” he made the world habitable for human society. In honor, the tribal confederation elevated him to leadership. He went on to found the Bronze Age Xia dynasty from about 2200 to 1750 BC, and he became venerated as the lord of the harvest in association with the river’s early irrigation works.

Yu’s legend reflected the paramount importance of water control in Chinese history. At birth it was said he emerged, fully formed, straight from the dead body of his father, who had previously tried and failed to control the floods by damming and diking the river’s flow, and had been put to death for stealing magic soil from heaven in order to build a dam. After careful study and surveys, Yu took up his father’s task by the different approach of laboriously dredging river channels and digging ditches and canals, including one bored through a mountain, in order to divert excess floodwaters to the sea. He labored selflessly alongside the workers, and after many years, finally succeeded in bringing the Yellow River and its floodplain under control. Confucius hailed him as the ideal of the humble, qualified government official who used his power for the public good, and thus the aspiring role model for China’s technocratic elite who governed in support of its emperor.

Water management helped frame the historic Chinese philosophical debate about the right principles for man’s governance of himself and his relations to the natural order. The sixth century BC Taoists argued that humble water’s yielding, yet relentless flow that wore down all hard and strong obstacles expressed the essence of nature and provided an exemplary model for human conduct. Taoist engineers designed waterworks to allow water to flow away as easily as possible, exploiting the dynamics of the natural ecosystem, just as they urged Chinese leaders to gradually win support for their goals through persuasive dialogue. Their main rivals, the Confucians, on the other hand, advocated a more forceful manipulation of both nature and human society to achieve the public good. They believed that rivers had to be forced, through dikes, dams and other obstructive constructions, to do man’s bidding as defined by rulers and technocrats. Although the Confucian view prevailed as the guiding tendency of Chinese hydrology from the Han Empire in the late third century BC to the twenty-first century postcommunist state, the underlying principles framed a fundamental engineering debate which has reemerged on the global level today as the world seeks environmentally sustainable solutions to the water scarcity crisis.

After nearly half a millennium, Yu’s Xia dynasty was displaced as the predominant power by the Shang and later the Zhou dynasties. Each was centered along a different, but overlapping part of the inland Yellow basin and flourished on indigenous irrigation agriculture without significant river or seaborne trade with other regions. The Shang was a Bronze Age tribe that with the help of the chariot imposed an aristocratic rule from about 1750 to 1040 BC over an area centered in the fertile north China plain and within reach of the Yellow River region’s tin and copper deposits. Although they were one of the earliest literate cultures east of Mesopotamia, the Shang’s many primitive customs included ancestor worship, human sacrifice, and various ritual consultations with the spirits by priestly diviners. The excavations at their city of Anyang yielded tens of thousands of “oracle bones” that were consulted by priests to reveal answers to the vital questions of life and death such as whether it would rain or when the barbarians from the north would attack.

North China’s climate was still much warmer and moister than today, and large-scale irrigation depended on extensive reclamation of cropland by draining fens and marshes by mass organized manpower. Their highly stratified social organization and large public works, including extensive walled cities, fit the model of the hydraulic civilization. Startling confirmation that millet was one of their staple crops was made in 2005 when archaeologists exploring the remains of an ancient village buried by an earthquake and flood discovered a bowl containing a well-preserved 4,000-year-old millet noodle 20 inches long.

With the conquest and amalgamation of the Shang culture by its former vassals, the Zhou dynasty, centered on its western border along a tributary of the middle Yellow River, more of the distinctive character of the emerging Chinese state took shape. While retaining the older dynasty’s use of kinship as the basis of political organization, the Zhou introduced the enduring political concept that the emperor’s ruling legitimacy stemmed not solely from divine right of birth but from a “Mandate from Heaven” based upon moral performance. Water control was a key test of the mandate. A good emperor was expected through magic and ritual to be able to deliver vital things like rain, peace and good harvests; droughts and floods, on the other hand, were events that signaled heaven’s disapproval. One legitimizing boon to Zhou crop irrigation was the innovation during their reign in the sixth century BC of productivity-enhancing iron tools. The advent of iron, however, also stimulated the deployment of new weaponry. From about 400 BC, what would emerge as the unified Chinese state was forged over nearly two centuries of incessant warfare between seven competing regional powers. During this period, the flight of northern farmers from the war zones accelerated the migration of Chinese civilization to the cultivation of rice paddies in the warm, wet south. Although China’s rice farming would not achieve its full critical mass until the seventh century AD, by the time the Ch’in dynasty consolidated its victory over its rivals in 221 BC—giving China its modern name—its domains extended throughout the Yangtze basin to the eastern seaboard.

For a dynasty whose own rule lasted only fifteen years, the Chin’s legacy was remarkable. Their new political structure of all-powerful emperor with a centralized bureaucracy replaced the old feudal system. Uprooted aristocrats were compelled to move to the emperor’s capital, while their local estates were superseded by a system of provinces and counties ruled by governors loyal to the emperor. Standardization was applied to weights and measures, writing systems and currencies, census-taking was begun, and taxation ruthlessly levied.

Like many great founding or restoring dynasties, the Ch’in were prodigious builders. Their accomplishments included building a vast road network and early segments of the Great Wall against marauding northern nomads. Of critical importance to their rise and legacy was the construction of large-scale, sophisticated irrigation and transport waterworks. Three in particular stood out. In their home state near the middle Yellow River they completed the Cheng-kuo Canal in 246 BC. By diverting water from two tributaries of the Yellow, it irrigated vast acreage in the Wei river valley north of its capital of Xi’an, site of the famous life-sized terra-cotta army of 8,000 soldiers, horses, and chariots that guarded the original Ch’in emperor’s tomb. Although heavy silting limited the irrigation canal’s productive life to a century and a half, the great increase in food and population it yielded played a vital role in providing the wealth, weaponry, and manpower the Ch’in needed to complete their conquest of China during the Warring States period.

Even grander and more impressive were the irrigation works of western Sichuan, north of the upper Yangtze, undertaken by a water engineer so accomplished he seems almost to have been an avatar of Yu the Great. Li Bing had been appointed provincial governor in 272 BC, nearly half a century after the region’s conquest by Ch’in generals. To enrich the province and win loyalty from the local population, he embarked upon an ambitious hydraulic engineering scheme intended to provide at once flood protection and reliable irrigation from the rapidly flowing, unpredictable waters of the Min River to the surrounding farming floodplain. Li Bing’s celebrated waterworks—still flowing today—were constructed chiefly along Taoist precepts. Rather than directly block the river’s forceful flow with a dam, a series of diversion weirs were built from flexible bamboo cages filled with rocks that were situated at a juncture where the natural contours of the river facilitated its division into an outer and an inner channel. The weirs could be adjusted to direct more of the water to one channel or the other depending upon conditions—to the outer channel to divert water against flooding or to the inner channel when irrigation water was needed. Li Bing emplaced three upright stone figures in the water as signal gauges. When their feet grew visible, the weir’s gates were to be opened to water the fields; when their shoulders became covered, the gates were closed. To complete the irrigation diversion so it could reach the farmland in the Chengdu plain below, Li Bing’s workers laboriously cut a channel through the mountainside by heating the rock by bonfire, then dousing it with water until it cracked and could be chipped away. Li Bing’s waterworks transformed the plains of eastern Sichuan into one of China’s most affluent irrigated farming zones. Covering some 2,000 square miles it sustained a population of 5 million—the maximum supported by the Egyptian Nile from ancient times until the nineteenth century. The outer channel also provided navigability. Later, in medieval times, Li Bing’s flowing Min River canals in the plains found additional employment turning thousands of waterwheels to hull and grind rice, and to power textile spinning and weaving machinery.

Li Bing also improved Sichuan’s production of precious salt by drilling early brine wells, some more than 300 feet deep, that drew salt directly from its underground sources rather than relying upon traditional salt harvesting from briny pools that had seeped up from the earth. His successors learned to use long, bamboo tubes with leather flap valves to create suction to draw the saltiest water from the deepest recesses. Bamboo plumbing became the mainstay not only of salt works, but eventually was applied ubiquitously throughout south China’s rice paddies by farmers as conduits for pump-lifted and relocated water and also in cities as rudimentary water mains.

The Ch’in’s third extraordinary water project was the Ling Chu, or Magic Canal, the world’s first transport contour canal, which was dug by following the natural topography of the surrounding landscape to avert complex tunneling and water-level management problems. By controlling and joining two rivers that flowed near each other in opposite directions, the 20-mile-long Magic Canal created a waterway link through the mountain ranges dividing northern and southern China. Built on the orders of the Ch’in emperor to support the conquering armies he had sent south in 219 BC, the Magic Canal made it possible to travel by boat through natural waterways and earlier channel cuts all the way from the lower Yellow River, south to the Yangtze, and beyond to the port of Canton—an astonishing distance covering 1,250 miles. Nothing like it had ever existed before in history.

The greatest beneficiary of this unprecedented precursor of the Grand Canal was not the Ch’in, however, but their immediate successors, the Han. Under the four centuries of Han rule, from 206 BC to AD 220, China’s powerful centralized state and high civilization flourished as one of the two greatest on Earth. Historians frequently have noted the many historical parallels between the Han and Roman empires. Their periods of greatest power, wealth, and influence were contemporaneous, their empires were of comparable geographic size, they flourished at the extreme edges of the civilized world at the time, and the proximate causes of the demise of each were barbarians attacking from the northern frontiers. Of course their political economies, cultures, and hydrological underpinnings were quite dissimilar. Rome did little intensive irrigation, relied for its wealth upon its Mediterranean sea-linked network of colonies, encompassed many cultures, and honored individualism. The Han Empire, by contrast, was the epitome of a hydraulic state: inward-looking and land-oriented, based upon intensively irrigated agriculture, and governed top-down by a despotic emperor and a cadre of expert technocrats overseeing mass peasant laborers.

The Han wasted little time in marshaling forced labor to add and improve canal segments to the great transport waterway they’d inherited, along with so many other remarkable, nation-building achievements, from the Ch’in. Much of their success was also owed to the extensive construction of irrigation and flood control canals, dams, and dikes, including some forty major water projects to control the Yellow River. Under the Han’s centralized administration, the patchwork of cropland in the Yellow River valley was organized into a single, intensively irrigated continuum that created China’s classic landscape and served as the economic and political heartland of the empire. Treadle chain pumps, a simple but extraordinarily useful small-scale technology for lifting water operated by the simple stepping motion of as few as one or two individuals, invented in the first century AD, was widely applied across China for drainage and irrigation and to supply drinking water. Eventually all water planning was centralized in a national office, establishing a tradition that has endured to the present day.

By 100 BC the Han state had become the largest landowner, with government monopolies also instituted over vital goods like iron, salt, and wine. Private merchants and the nascent profit-driven market system that had begun to develop under the Ch’in but conflicted with Confucian precepts of governance were suppressed by regulation. Sovereign taxing power was used to weaken disfavored classes and accrue authority to the Han state. In time, all urban markets became government controlled, with officially set commodity prices and taxation on commerce that filled the treasury.

The Han’s bid for state domination over economic life was made easier by the fact that wealth creation remained predominantly based on intensively irrigated agriculture at inland locations along mostly navigable, relatively easily governed arterial rivers. Despite China’s long coastline, sea trade—always problematic for sovereign states to control—remained underdeveloped due to the geographical fact that there were simply few enticing, easily reached Far Eastern civilizations with whom to profitably trade. Although some unregistered itinerant merchants survived and even flourished trading between cities and at the peripheries of society, mainstream Chinese civilization developed a strongly inward-looking orientation that tended to accrue great power to the central state.

The Han emperors encouraged the expansion of industry, some using water as a vital input. Most importantly this included its precocious iron casting industry. A process for casting iron into molds, one of history’s key inventions, had been discovered in China as early as the fifth century BC, nearly 1,800 years before cast iron became widespread in Europe. In the third century BC, the Chinese iron masters discovered a heating and cooling process that produced a malleable cast iron with the strength and solidity that rendered it nearly as good as steel. The Han employed it in important applications, such as making cast-iron plowshares for agriculture and pans in which brine could be evaporated for the mass production of salt. Within two years of nationalizing all cast-iron manufacturing in 119 BC, Han leaders had established 48 state foundries that employed thousands of workers. To achieve the high temperatures necessary for casting iron, the Chinese employed efficient bellows to stoke the blast furnaces. An early innovation that greatly increased cast-iron production was the application of waterwheel power to the bellows. In AD 31, noted Chinese engineer Tu Shih invented a powerful, widely imitated, water-driven bellows used to produce cast-iron agricultural implements.

Unlike the Romans, who used waterwheels chiefly to grind grain and for mining, the Chinese also pioneered the large-scale application of waterpower for industrial production. Indeed, for well over a millennium, China was the human civilization’s leader in harnessing water as energy to do useful work. Powerful vertical waterwheels, with gearing to turn several shafts, were used to operate trip-hammers to pound iron into shapes, hull rice, and crush metallic ores, as well as for other applications, by the AD 200s and 300s, many centuries before they appeared in Europe. By AD 530 Buddhist monasteries in the northeastern city of Loyang were even operating waterwheel-powered flour-sifting and -shaking machines based on the same essential design as that used by the steam engine—albeit with the crucial absence of steam power itself—that would galvanize England’s eighteenth-century Industrial Revolution.

Not surprisingly, the Chinese would become world pioneers in ensuing centuries in applying waterpower to the ancient art of silk making—one of trade history’s great monopolies that enriched imperial China for centuries. The art of producing silk filament from the cocoons of the mulberry silkworm and weaving it into textiles was first discovered as far back as the Stone Age. Hot water played a critical role in the silk-making process, in what was perhaps history’s earliest example of water use in industrial production. To net one pound of raw silk, silkworms had to eat 100 pounds of mulberry leaves and produce about 15 pounds of cocoons. Great skill was required to unwind the silk filament from the delicate cocoons. It was accomplished by first soaking the cocoons in boiling water to kill the chrysalis; the strands were drawn out, then joined together and finally woven to produce the soft fabrics desired worldwide.

The Romans first encountered silk in 53 BC when fighting the Parthians in modern Iran. By the first century AD, Roman demand for popular Chinese silk became such a burden on Rome’s balance of trade that Emperor Tiberius tried to forbid the importation of silk garments. China’s monopoly advantage in the silk trade with the Roman world endured for another 500 years. It was finally broken by a famous case of industrial espionage when two Christian Byzantine monks traveling in China stashed silkworm cocoons in the hollow of their staffs and returned with them to Constantinople, which promptly established its own lucrative silk industry by the end of the sixth century.

The Han began shipping large quantities of silk to Persia and the Levant on taxed and protected camel caravans across the famed 4,000-mile-long Silk Roads of arid central Asia in 106 BC shortly after discovering, to their surprise, the existence of a fairly advanced civilization in the far West—Rome. The availability of freshwater sources dictated the trade routes and the scale of the camel trains. The several Silk Roads started at the huge city of Chang’an (the former and later X’ian) in the Yellow River valley, skirted inside the Great Wall to the Jade Gate and then went beyond China’s borders to follow a string of oases across the harsh wind- and sand-blown high deserts of central Asia at the foot the Himalayan, Altai, and Tien Shan mountains. Oases formed wherever mountain streams rushed down, sometimes flooded by snowmelt or violent storms. A northern and a southern route came together between the Jaxartes and Oxus rivers and crossed through Samarkand and Bukkara in modern Uzbekistan, before following various roads through Persia and Mesopotamia to Roman Syria on the Mediterranean; another branch route headed south to India.

The entire trek was made possible only by the astonishing strength and water-storing capacity of the two-humped Bactrian camel, which unlike its one-humped Arabian cousin was able to tolerate the freezing temperatures of the high Asian deserts. Caravans of sturdy, woolly Bactrian camels plodded 30 miles per day carrying 400 pounds of goods on their backs. Although larger trains offered greater safety, most of the caravans were no larger than 50 men and their beasts since that was all the scarce water resources en route could support at any one time.

Many of the oasis outposts thrived as important entrepôts of civilization, where both high-value luxury goods and new ideas were exchanged free from government control. In addition to silk, China shipped iron goods, ceramics, jade, and lacquer; the West sent back gold, ivory, precious stones, coins, glass, Persian sesame seeds and nuts, and, from India, spices and perfumes. Buddhism entered China and the Far East from India along the Silk Roads, its teachings spread by two Buddhist monks in the first century AD, overlapping the simultaneous early spread of Christianity in the Roman Empire.

Trade on the Silk Roads reached its apex in the seventh and eighth centuries. Then, suddenly, after the annihilation of a Chinese expeditionary force by a Muslim army at the Talas River near Samarkand in 751 helped trigger the collapse of Chinese power across central Asia, the Silk Roads closed for over four centuries. It was one of history’s obscure skirmishes that in retrospect had outsized consequences. The silk trade was redirected to the Indian Ocean spice routes that were increasingly dominated by Muslim shipping, accelerating the rapid rise and global reach of Islamic civilization. The Silk Roads were finally reopened for travel by the Mongol Empire, whose thirteenth-century conquests under Genghis Khan and his heirs spanned from China to Persia. It was at the end of the thirteenth century that Venetian Marco Polo, a jewel merchant, made his famous trading expeditions from Venice to the Mongol overlords of Cathay (China). But by that time the Muslim-controlled, two-way seasonal monsoonal Indian Ocean sea route had established itself as the most reliable and economical way to transport goods between East and West and retained the predominant share of the traffic.

With the fall of the Mongols, the glory days of the Silk Roads ended forever. But the combination of these two overland and sea routes succeeded in establishing an enduring, unregulated, long-distance, Old World trading network based on market economic exchange that competed with and would eventually supplant the traditional authoritarian command organization of centralized states. International trade had reached a peak at the contemporaneous high point of the Roman and Han Empires in the early Christian era. It then eroded with their declines. But gradually, with the restoration of civilized order in the Orient and Occident it built up again. By about AD 1000 the web of international exchange had achieved a critical mass of sufficient density and volume to propel its expansion throughout the second millennium and ultimately evolve into the integrated global market economy of the twenty-first century.

The Han empire finally collapsed in AD 220, like Rome, under pressure from barbarian raiders from its northern frontiers and internal depopulation and weakening from exposure to unfamiliar infectious diseases inadvertently imported on trading ships and Silk Road caravans. Indeed, the Han imperial state had never fully recovered from the combination of a short-lived usurpation and a disastrous course change of hundreds of miles in the flooded Yellow River in AD 11. The delay of several decades in repairing the river’s damaged irrigation and protective infrastructure led to inadequate food supplies, famine, disorder, and massive emigration along China’s vital northern defensive frontier. Manpower shortages, in turn, weakened the size of the Han’s military presence. But the essential underlying reason for the Han’s eroding northern strength was its inadequate supply and control of irrigation water to grow enough food to maintain a sufficiently large army there—north China’s relative shortage of water resources. A third-century Chinese report highlighted that “there was insufficiency of water for the fullest use to be made of the productive power of the soil.” Nor was there yet in place any efficient network to transport compensatory southern food supplies to the northern borders.

The historical parallels between Rome and China endured into the sixth century AD with native efforts to reconstitute the fallen empires in each region. The initiative of Constantinople’s Byzantine Roman emperor, Justinian, to reunify the Latin West ultimately failed, leaving Rome itself as a shrunken ruin of its former glory until the Renaissance. In China, by contrast, reunification succeeded. Restoration under the Sui from 589 to 617 AD and the successor T’ang dynasty until AD 906 paved the way for China’s medieval economic revolution and its golden age when Chinese society soared to the zenith among world civilizations.

Why did China’s reunification succeed, yet Rome’s fail? One outstanding distinction was China’s building of the imperial Grand Canal linking the Yangtze and the Yellow rivers. Completed at a breakneck pace in only six years in 610 by the Sui—who, like the Ch’in, were prodigious and ruthless infrastructure builders—using some 5 million conscripted male and female laborers, the nearly 1,100-mile-long, elongated S-shaped Grand Canal linked up local canal segments that had been built episodically since the fifth century BC and added new segments. In all, it created a stupendous 30,000-mile-long national inland waterway system that enabled a united China to ship vital rice supplies grown on the terraced hillside paddies of south China to the large population centers and army troops located on the Yellow River to defend against the continuing threat from bellicose nomadic horsemen from the Asian steppe.

Not only did the Grand Canal overcome the vulnerability that had vanquished the Han. By bridging China’s north-south hydrological fault line, it synergized the natural and human resources of the two diverse geographical zones to help launch China’s brilliant, medieval golden age. All China was invigorated with fresh economic and cultural energy. In contrast to the Han, the Sui and T’ang dynasties presided over a more robust double base, one in the traditional Yellow River valley in the north and an even more productive southerly one that had been steadily growing for centuries around the Yangtze.

The old Roman Empire and Europe, by contrast, lacked the unifying impetus of any such inland waterway. Its major arterial river system, the Danube-Rhine, was ill-suited to that purpose because it flowed away from the early hubs of Mediterranean European civilization, through difficult, rain-fed agricultural soils, and along an unstable frontier boundary besieged by warlike tribes. The open waters of the Mediterranean were far less effectively controlled and thus less conducive to playing a uniting role than large irrigation rivers. From this point on, the histories of China and Europe diverged widely. While the European territory of the old Roman Empire remained a fragmented jigsaw of competing states and endured the stagnation of the long dark ages, the Grand Canal served as the electrifying fulcrum of China’s medieval economic revolutions in transport, agriculture, and industry.

China’s Grand Canal was one of mankind’s stellar engineering achievements. It was the largest artificial transport waterway ever built and required a larger labor force than the one that erected the Great Wall, most working with their bare hands and shovels and uncounted hundreds of thousands giving their life to the project. It ultimately spanned eastern China for 1,100 miles from the port city of Hangzhou south of Shanghai to Beijing on the northern frontier with a gigantic channel 10 to 30 feet deep and up to 100 feet wide. It featured 60 bridges and 24 locks to manage elevation variations and summit level water flows. Its waters teemed with commercial vessels of all shapes and sizes, powered by sail, oars, and paddle wheels, transforming the world’s most densely populated trading area into a single national economic market. Rice-laden barges came and went from huge granaries that the government maintained at key junctures along its route to furnish the food lifeline for China’s national security. The easy movement facilitated centralized governance by grain tax collectors, bureaucrats, and soldiers en route to army garrisons. Due to its surpassing importance, the Grand Canal became a key political barometer, and driver, of Chinese history. Whenever the canal was threatened, cut, or left in a state of disrepair, China was generally in the throes of a crisis or immersed in prolonged decline or political lassitude. A robust Grand Canal system, on the other hand, spurred internal growth and security, rendered superfluous the pirate-harassed sea transport links between the southern food supply and the northern defensive garrisons, and generally encouraged China’s inward-looking, autarkic impulses.

As a result of the canal, water transport became many times less costly, at least one-third less than shipping by land. Government policymakers made ongoing improvements a top priority. One key advancement was the world’s first double canal pound lock at an opening onto central China’s Huai River. It was built in AD 984 at the order of Ch’ia Wei-yo, a Sung government assistant transport commissioner, who was seeking ways to minimize theft and damage to ships and cargo caused by existing methods for moving vessels between differing water levels. At the time, cargo ships were manually hoisted out of the water with ropes by large labor crews, dragged up a slipway ramp cut into the bank, and then relaunched from a second slipway into the water at the level of the second waterway. Pound locks, which came into widespread use on the Grand Canal network during the eleventh century, impounded water between two lock gates; vessels were either lifted or lowered simply by adding or withdrawing water within the impounded portions. Boats could easily be lifted up to five feet in a pound lock. A graduated series of pound locks enabled canals to lift boats to unprecedented elevations—the summit level on the Grand Canal, for instance, was 138 feet above sea level. Moreover, the pound lock conserved precious water, allowing canals that often went dry in summer to operate more days of the year. One double lock built where a branch of the Grand Canal joined the Yangtze enabled the passage of ships five times larger than possible under the double slipway system.

River cargo volumes soared from early T’ang times. In the eighth century, combined tonnage of the government’s 2,000 ship Yangtze salt and iron fleet alone reached a third of the total transported on all British commercial vessels in the mid-eighteenth century. During the Sung dynasty from 960 to 1275 government officials improved their communication by using the waterway to distribute the world’s first national newspaper, an official government gazette. As shipping traffic increased, private shipping brokers became increasingly active, matching and administering contracts between buyers and sellers, storing goods at their warehouses and serving as clearinghouses of market prices and conditions. Where the commerce of inland waterways merged with the sea, great port cities with market activity arose to trade in spices, silk, and other luxuries with the rest of the world through shipping networks that extended across the Far East, India, Arabia, and the Mediterranean.

During the T’ang era, the Chinese were content to sail the seacoasts with the two-way monsoons, south in winter and north when the winds reversed in summer, and to rely upon Arab, Persian, and other foreign shippers for long-distance sea trading. By the Sung dynasty, Chinese nautical mastery was world class, featuring massive ships built with iron nails from its foundries, watertight compartments unknown in the rest of the world, a huge sternpost rudder for steering, buoyancy chambers, and distinctive, narrow fanlike sections of canvas sails stretched between bamboo masts that looked much like a Venetian blind. Navigation was facilitated by the invention in 1119 of the mariners’ compass, one of many important Chinese innovations to migrate westward. As a result, Chinese seafaring gradually grew more ambitious. Yet seafaring in China’s golden age never approached the awesome scale of its inland river shipping, which so impressed Marco Polo, native of Europe’s greatest seaport, Venice, then with a comparatively tiny 50,000 inhabitants. Describing the Yangtze at the smallish port city of I-ching, he related that “the amount of shipping it carries and the total volume and value of its traffic…exceeds all the rivers of the Christians put together and their seas into the bargain…I have seen in this city fully five thousand ships at once…and there are on (the Yangtze’s) banks more than two hundred cities, all having more ships than this.”

The national Grand Canal waterway transport network also gave powerful impetus to China’s rice-farming revolution (eighth to twelfth centuries), one of the decisive events in Far Eastern history. Originally a dry crop, wet rice had been extensively cultivated in naturally flooded fields alongside the monsoonal rivers of Southeast Asia by small communities since the third millennium BC. It first arrived in China from India around 2000 BC. After about 500 BC more intensive new irrigation methods that allowed cultivation on a larger scale and over a wider range of landscapes began to spread.

Rice irrigation demanded solving formidable water challenges. First, there was the problem of converting nature’s hydrological excess of rainfall and floods from an insuperable obstacle into a productive irrigation resource. The transplanted young roots had to be kept submerged in shallow water for several months, after which the water was drained off. Farmers had to prepare, level, and wall the terraced paddies of south China’s hillsides, drain and refill paddies at timely moments, and keep the entire system constantly flowing with muddy water in order to provide sufficient oxygen to the rice plants and to suppress infestations of malaria-carrying mosquitoes. A technical array of dams, sluice gates, water-lifting norias, simple treadle pumps, and a network of bamboo pipes enabled the process. The labor was immensely intensive. But so were the rewards. Inundation transformed poor, quickly depleted soils into perennial rice paddies that never had to lay fallow so that yields could sustain population densities far higher than those that could be fed by achievable yields of wheat or maize—thus providing the demographic profile that distinguished Asia’s history. In China, it completed a population and dietary transformation that had been evolving gradually over many centuries as many Chinese farmers moved south away from the millet and wheat fields of the Yellow River basin.

China’s rice farming revolution reached its apogee in the early eleventh century with the government’s importation from Champa in central Vietnam of a variety of rice that matured in only sixty days. The fast-growing Champa rice also required less water than domestic varieties, so it could be grown on drier hillside paddies that soon were irrigated for the first time. In 1012, on the orders of Sung emperor Chen-tseung, samples of the seeds of Champa rice were distributed to farmers in a conscious effort to expand food production. The effects were astonishing. Suddenly, two and three crops could be grown on an expanded area of irrigated land. Rice production soared. China’s population promptly followed. By the end of the twelfth century it reached 120 million—double the peak achieved by the Han in AD 2 and the early T’ang in the 700s. Some 75 million lived in the south, inverting the historical population balance favoring the north, and transforming China permanently into a densely populated nation primarily of rice eaters—a profile that defined its economic and social structure until the twenty-first century. Abundant food shipments along the Grand Canal drove the rise of Earth’s largest urban centers of the times, cities such as Hangzhou, Kaifeng, Louyang, and Beijing, that also pulsed with resurgent private market commerce and industry. During the Sung dynasty, China’s greatest age, these urban centers became hubs of a remarkable scientific renaissance, entrepreneurship, and a protoindustrial revolution six to seven centuries before Europe’s. Many great inventions were developed, some which later migrated westward through the Indian Ocean and Silk Road trade routes to stimulate Islamic civilization and later still Europe’s rise.

By 1100, China was by far the world’s indisputable technological leader. Techniques were being used in smelting iron with coke, canal transportation, bridge design, water-powered textile manufacturing, and producing iron farm tools that were not paralleled in Europe for some 600 years. In addition, China was the first civilization to discover that mixing saltpeter (potassium nitrate) with carbon and sulfur produced a volatile substance that exploded when heated—gunpowder. It also pioneered firearms, scientific instruments for measuring the heavens and navigation, hydraulic clockwork, printed books, moveable type, paper money, and the first toilet paper.

One of the great northern Sung cities, and probably the most important place in the world at the time, was the capital, Kaifeng. In 1100, it was larger than ancient Rome with a registered population plus army of about 1.4 million. Its strategic location near the junction of the Grand Canal and the Yellow River not only put it within easy supply of the rice barges from the south, but also along the water transport routes that brought abundant coal and iron from north China’s mines. Kaifeng rose as an important industrial center. Spurred by deforestation which overtook the region by about 1000, Chinese iron smelters had made the breakthrough discovery of how to use coal in place of charcoal to cast iron from coke-burning blast furnaces. They also invented a decarbonization method to produce large quantities of hard steel from cast iron. Iron production soared. By 1078, China was producing 114,000 tons of pig iron, double England’s total output 700 years later.

The story was similar in textile manufacturing. Before 1300, China’s precocious textile artisans were operating water-powered spinning machines that could draw several silk filaments simultaneously from boiling water-immersed cocoons—some 400 years before England’s first water-powered spinners began producing silk stockings in Derby to help launch the industrial factory system. Mechanical clocks, which China invented at least two centuries before Europeans, with sophisticated gearing, precision, and self-regulatory mechanisms, helped government administrators accurately keep the all-important official calendar. The famous 30-foot-tall noria-type water clock, with quarter-hourly gongs and bells, erected in 1090 in a Kaifeng pagoda was even used to calculate favorable heavenly synchronizations of the Chinese emperor’s procreation schedule among his 121 wives and concubines.

Yet China’s technological leadership did not make it invulnerable to its age-old menace of nomadic invasions from the north. In 1126 the barbarian Ch’in Tartars, armed with iron-weapon-making know-how imported from China and with its traditional, potent cavalry, overran Kaifeng and northern China. They, in turn, were expelled by the Mongols in 1234. The surviving Southern Song dynasty established a new capital at Hangzhou. Utilizing the natural protection afforded by the wide Yangtze River, it built its primary defense around a naval fleet of hundreds of newly designed, armored river- and canal-fighting vessels propelled by paddle wheels and treadmills and armed with onboard projectile-throwing machines, crossbowmen, and pikemen. Behind the Yangtze lay the second line of defense—the muddy rice paddies in which the Mongols’ fearsome mounted cavalry bogged down. These defenses helped them survive the onslaught of Genghis Khan’s heirs until 1279.

The ferocious Mongol conquests from 1206 led by Genghis Khan created the largest land empire in world history. The trademark of this tribal confederation of nomadic, mounted archers from the arid steppe was the merciless slaughter of defeated populations and their domesticated animals, wholesale pilfering, and razing of cities, irrigation works, and other vital infrastructures of civilized life. When Genghis died, undefeated, in 1227 the Mongol empire spanned the entire central Asia steppe from the Volga River in the west to the Amur River in the east. His successors expanded into eastern Europe as far as Poland and Hungary by 1241. Much of the Islamic Middle East capitulated to Mongol warriors, who in 1258 savagely destroyed Baghdad and its caliphate. Mongol armies reached the Adriatic by 1258 and the edge of Africa by 1260. By 1279 all of China was in Mongol hands, the first time in history that China was ruled completely by foreigners. The zenith of the Mongol empire was reached under Genghis’s able grandson, Khubilai Khan, who ruled from 1260 to 1294. He set up China’s Yuan dynasty, which had its seat of government in Beijing. It was Khubilai’s Mongol-led China that Marco Polo served and famously described to the transcriber of his Travels, Rustichello of Pisa, while the two languished in a Genoa prison after the Venetian galley on which Marco had been traveling was captured during a September 1298 battle between Mediterranean trade rivals Venice and Genoa.

The Mongol conquests were to be world history’s last great wave of invasions by nomadic, pastoralist warriors that had disrupted and challenged the settled, civilized lifestyle since the Bronze Age. Before the Mongols, the water-fragile central Asian steppes had produced invasions from bellicose confederations of Hsiung-nu, Juan-juan, and the Mongol’s close cousins, Turkmen; the latter allied with China in defeating the Juan-juan in the mid-sixth century, and subsequently divided into two groups and eventually infiltrated and rose to political prominence in Islamic society. The nomads’ ignorance of civilization’s complex technologies, including sophisticated water management, proved to be one of their grave weaknesses in trying to govern the societies they conquered. The rule of the Mongol’s Tartar predecessors, for example, had been undermined by a decline in canal traffic capacity and related diminution of iron and agricultural production, resulting from their failure to undertake timely restorations when the flooding Yellow River burst its restraining dikes in 1194 and cut a new path to the sea.

Well into the thirteenth century the Mongols themselves still crossed rivers using primitive, inflated skins and rafts. Their conquest of southern China succeeded after forty-five years only when a former Sung commander, Liu Cheng, defected to Khubilai and built a river naval fleet capable of challenging Sung dominance of the Yangtze River. The decisive confrontation was a five-year river-and-land siege of Hsiang-yang, a key river fortress that controlled the main access route to the Yangtze heartland. When success came in 1273, south China finally lay open to the Mongols. With its cavalry bogged down in muddy rice fields, its infantry unfamiliarly led the invasion. The final remnants of Sung resistance were extinguished in early 1279 following their large naval defeat off the coast of Canton, when a loyal minister jumped in the ocean, drowning himself along with the last imperial prince.

Even then, the Mongol Yuan dynasty had very limited success exploiting the rich potential of China’s water resources. Despite building an impressive naval fleet, Khubilai was unable to extend the Mongol’s military land prowess to sea power, as exemplified by the unsuccessful large naval invasions against Japan in 1281 and Java in 1293. He failed as well to wrest ocean shipping from the Muslims. Like his predecessors, Khubilai devoted high priority to enhancing the Grand Canal. He restored the connection to the Yellow River, disrupted by the course change of 1194, straightened the canal, and added a northern extension to his new capital, Beijing, on the extreme northeastern frontier. Food security and prosperity increased. Yet his engineers failed to make the crucial canal innovation necessary to supply sufficient water to enable food transport ships to readily pass year-round over the summit level of the hills leading to Beijing. This contributed to the Yuan dynasty’s downfall. Sea convoys temporarily mitigated the vulnerability, but finally piracy and rebellions in the south disrupted reliable food deliveries. The breakthrough “Heaven Well Lock” of the Grand Canal would be made during the restoration by the Ming dynasty, which finally toppled the despised, plague-weakened Mongolian Yuan after 1368.

Like many nativist restorations, the early Ming era was marked by a revival of old traditions, renewed economic and creative vigor, and xenophobia. Water engineering advances played a prominent role, above all in shipping, reconstruction of iron chain suspension bridges, and in major improvements of the Grand Canal. The Ming’s superior command of water resources, in fact, had played a decisive role in driving the Mongols back into the northern steppe. In 1371 the Ming navy, armed with iron prows and firearms, broke through the chains and bridge of boats defending the gorge at Chü-tang, the key to controlling Sichuan.

Once in power, Ming seagoing vessels, meanwhile, reopened a 500-mile-long transport supply line of food, clothing, and weaponry that enabled the reconquest of southern Manchuria. Once victory was secured, this sea convoy from the south, manned by some 80,000 men, rapidly became an indispensable lifeline to supplying rice to Beijing and the Ming’s northern defense lines. When the Ming relocated its own capital seat to Beijing in 1403, it simultaneously launched an enormous, state-run shipbuilding program to secure its control over the vital sea-lanes. Between 1403 and 1419, the shipyards near Nanking alone turned out 2,000 ships. The Ming fleet featured 3,800 ships by 1420, including 250 giant, long-distance “treasure ships,” some up to 440 feet long and 180 feet wide, with square linen sails on four to nine masts towering up to 90 feet high, capable of carrying 450 to 500 sailors and displacing up to 3,000 tons apiece—ten times more than the flagship Vasco da Gama sailed in his historic voyage around the Cape of Africa into the Indian Ocean at the end of the century. The ships incorporated all China’s advanced innovations, making it the supreme naval power of its time.

The Ming soon exercised their new sea power with a series of spectacular maritime expeditions that revealed China’s clear naval superiority in the great age of sail that was just dawning around the world. The most famous of these were the seven expeditions between 1405 and 1433 commanded by Admiral Cheng Ho, a Muslim and court eunuch devoted to the emperor. Cheng Ho’s first fleet had more than twice as many vessels as the Spanish Armada 150 years later, and included 62 giant treasure ships. It far outclassed the Arab dhows and Indian vessels it met in the Indian Ocean. In his seven voyages, Cheng Ho’s 27,000 man fleet easily established control in the Indian Ocean, over the Malacca Strait, Ceylon, and Calicut, India, and became an influential force at Hormuz at the mouth of the Persian Gulf. Cheng Ho also sailed up the Red Sea, where some Muslim crewmembers disembarked to undertake a pilgrimage to Mecca, and south along the East African coast as far as Malindi in modern Kenya, where he obtained a giraffe as a novelty present for the emperor in Beijing. In contrast with the European voyages in the Indian Ocean during the following century which were undertaken to secure treasure, profitable trade routes, and eventual military dominance, Cheng Ho’s primary mission was instead to win homage for the glory and power of the Ming rule. Few dared resist his demands of honor for the “son of heaven” in Beijing when his warships appeared off shore. Gifts were diplomatically bestowed upon those who acquiesced. Resisters were militarily disciplined—but not massacred, as they were by Europeans three-quarters of a century later. When a ruler in Ceylon showed reticence, for instance, Cheng Ho had him seized and shipped back to China’s Imperial Court for proper disciplining.

Then, in 1433, all the expeditions abruptly ended. Edicts from the emperor strictly limited Chinese seafaring and contacts with foreigners, the construction of oceangoing ships, and even the very existence of ships with more than two masts. Cheng Ho’s great warships were left to rot. Naval personnel were redeployed to smaller ships that plied the Grand Canal. Eschewing its power, China turned inward, away from the world.

It was a remarkable moment in history when a great power, possessing all the means to dominate all worlds it encountered and with vessels seaworthy enough to cross all the open oceans, including the Pacific to the New World, suddenly decided not to press its advantage. Historians have mused how world history would likely have been radically different had the Portuguese encountered a powerful Chinese empire controlling the key ports and sea-lanes of the Indian Ocean when they rounded the southern African cape in 1498 to establish the world-changing direct ocean link between Europe and the East. Indeed, one cannot help but further wonder whether Europe itself might have been subordinated and colonized if, instead of cutting off from the world, China had applied its maritime and industrial superiority to press southward around Africa, to master the Atlantic Ocean wind and current systems, and announced itself to Europe and the Americas before Columbus and da Gama ever hoisted sail.

Why did China suddenly turn inward? Xenophobia and angst about the revival of Mongol power in the north, where the modern Great Wall was being built, were motivating factors. But the world-history-shaping about-face in China’s geopolitical strategy was made possible, and also driven, by the successful completion in 1411 of the greatest of all Ming water engineering triumphs—the New Grand Canal. The dredging, repair, and expansion of the entire Grand Canal had become a top priority once the Ming government moved China’s capital back to Beijing in 1403. By providing the means to supply the northern frontier’s fortresses with food and munitions, the Grand Canal became the vital defensive artery for the entire country. The existing sea transport system was not reliable enough to provide the needed food supplies for the northern frontier due to piracy and the inherent natural uncertainties of sea travel. To move supplies along the inland Grand Canal extension to Beijing, however, the Ming had to devise one canal innovation that had stymied the Yuan engineers—how to supply enough water to enable perennial passage, even in the dry season, over the highest point in the hills. Often large cargo ships were sidelined for up to six months until water levels refilled with the seasonal rains. The breakthrough Heaven Well Lock was made in 1411. The new lock split the combined flow of two rivers and allowed managers to regulate seasonal water flows through a network of 15 locks. Heaven Well Locks were introduced along the length of the Grand Canal, which at a stroke became a reliable, all-season inland waterway and all-important supply line of the Ming dynasty. With the government employing 15,000 boats and some 160,000 transport workers, food supplies to the north rapidly quadrupled.

The sea transport supply route became redundant and was shut down. “With the re-construction of the Grand Canal to Peking (Beijing) in 1411, and the abolition of the main sea transport in 1415,” China historian Mark Elvin observes, “the navy became for the first time a luxury rather than a necessity.” After 1415, shipbuilding resources were diverted to the building of canal boats; after 1419 all ocean shipbuilding ceased. The decision to end Cheng Ho’s expeditions after 1433 and rely exclusively on China’s internal resources, therefore, was but another sequential step in the same inward political direction.

The completion of the New Grand Canal proved to be the decisive turning point that enabled China to make its history-changing policy U-turn and cut off from the rest of the world. Moreover, by artificially creating a more self-contained, command-controlled, hydraulic environment, the New Grand Canal also enhanced the centralized authority of the Ming state. The emperor and his conservative neo-Confucian mandarins, in alliance with the landed agricultural interests, used this power to suppress the surviving private merchant class that had been such a vibrant component of the Sung golden age. This contrasted starkly with contemporaneous developments in Europe, where the absence of a unifying inland waterway system and the focus on transport by sea helped produce smaller states, whose competition led to the expansion of unregulated trade and free-market enterprise.

Although economic growth continued after the mid-fourteenth century, China’s inner dynamism and creative inventiveness gradually declined. This also helped illuminate the second historical enigma why it was that industrially advanced medieval China, possessing virtually all the requisite scientific know-how, did not make the next advances to create modern industrialism hundreds of a years before the decisive breakthroughs were finally achieved in the West. A key part of the answer, simply put, was that the reassertion of a strong, isolationist, centralized state inhibited the emergence of a market-driven economic engine that in eighteenth century England ultimately combined the profit motive with innovations in technology to make the breakthroughs that fueled the Industrial Revolution. Another part of China’s failure to achieve early industrial takeoff also stemmed from the chronic surfeit of cheap manpower resulting from the dense populations produced by its rice farming society. This diminished both the political and economic incentives to develop labor-saving technologies, such as the steam engine, whose catalytic synergies with iron were to drive the early industrial age.

China’s isolation lasted almost four centuries. Yet by trying to preserve its ways without engaging the innovative ferment of the outside world, it made itself vulnerable, once again, to external incursions. Just how far China had fallen behind technologically was stunningly demonstrated by mobile British steam gunboats during the first Opium War of 1839 to 1842, which forcibly reopened the helpless empire to the world. China’s foreign trade contacts at the time were restricted to a single port, Canton. Seeking a way to balance a lopsided trade pattern favoring Chinese exports to the West of tea and other luxuries, the British had gradually cultivated a Chinese market for opium grown in its Bengal, India, colony. As Chinese opium addiction, and with it opium imports, mounted, Chinese officials in 1839 resolved to interdict importation of the drug. At first they appealed to England to halt its opium exports. With unimpeachable logic, they noted in a letter to Queen Victoria that opium was banned in England and that the same principle should apply to China. To the British, however, moral or legal consistency was subordinate to its mercantile and colonial interests. The Chinese implorations were rebuffed. In an act reminiscent of America’s Boston Tea Party, Chinese officials seized some 30,000 chests of drugs from British and other European merchants and dumped many into the river. Britain’s response was to dispatch a fleet of cannon-armed, paddle-wheel, steam gunboats to the mouth of the Canton River in June 1840. To the amazement of the Chinese, the steamboats seemed to have the power to fly across the water, regardless of wind or current. It took only half a dozen skirmishes for Britain to win the Opium War. British steamers sailed up Chinese rivers, entering the Yangtze River to take Shanghai and then the strategic choke point where the Grand Canal met the great river. When Nanking was threatened in August 1842, China capitulated to Britain’s unequal and humiliating treaty terms. In addition to indemnities for merchant losses, the Chinese were compelled to cede in perpetuity to Britain the barren island of Hong Kong and to open five port cities to the free trade of low-cost British merchandise, which Britain reasonably expected would help enrich its world-class manufacturers. France and the United States soon demanded and received similar rights; the second Opium War in the late 1850s ended with Anglo-French forces occupying Beijing, more port openings, and the right of foreigners to travel inside China, including having diplomatic representatives dispatched to the emperor’s Forbidden City at Beijing.

The humiliating defeat in the Opium Wars rendered publically visible the extent of the demise of China’s 2,000-year-old empire. It added insult to the widespread disaffection with the ineffectual government and helped stir the rebellions that ultimately toppled it. A telltale sign and fomenter of this internal decay was once again waterworks deterioration. Millions died in three major dike breaks in the Yellow River between 1841 and 1843. In 1849, the worst flood in a century ravaged the lower Yangtze. The major shift of the Yellow River toward its present northern course in the 1850s caused major breeches in the Grand Canal. Northern sections of the canal were left unrepaired and the critical channel supplying Beijing was abandoned altogether following the Taiping Rebellion and other major uprisings in the 1850s and 1860s. Floods worsened in the late nineteenth century due to inadequate diking and waterworks maintenance, hastening the final days of the ruling Manchu dynasty and the long Chinese empire in the 1911–1912 revolution. The revival of the Grand Canal and other major water infrastructure, reminiscent of the restoration of new dynasties, began with the coming to power after a Japanese occupation and long civil war of the post–World War II Mao Zedong–led communist regime.