Agriculture and Trade Sustained Song Prosperity

Prologue: The Ship in the Mud

In 1973 people working along the shore of Quanzhou Bay, on the coast of Fujian province, found old timbers sticking out of the mud at low tide. The next summer archaeologists dug them out. What emerged was the lower half of a large wooden sailing ship. Its upper decks and masts were long gone, but the hull survived, about 79 feet long and 30 feet wide, and it was divided by twelve wooden walls into thirteen separate compartments.

The compartments were still full of cargo. There were more than two tons of fragrant wood from Southeast Asia, the kind burned as incense or used in medicine. There was pepper, betel nut, cowrie shells, tortoiseshell, cinnabar, and ambergris, a rare substance from the Indian Ocean prized for perfume. There were Chinese ceramics and hundreds of copper coins, and dozens of small wooden tags that seem to have labeled goods for their owners. The latest coins were minted in the Xianchun reign (1265–1274). The ship had sunk, it seems, around 1277, just as the Song dynasty was collapsing before the Mongols.

The Quanzhou ship is a small object with a large story behind it. Its cargo had come from across the sea to a Chinese port that was then one of the busiest in the world. Its design—a big hull, watertight compartments—was more advanced than most ships anywhere. And it belonged to a dynasty that, a century and a half earlier, had lost the whole northern half of its territory to the Jurchen Jin.

That is the puzzle Lecture 1 left behind. In 1127 Song lost Kaifeng, its emperor, and the north China plain. Yet the dynasty survived for another 152 years, and in that time it ran one of the richest economies on earth. How could a dynasty lose its northern capital and still sustain a prosperous economy?

The answer is not a list of inventions. It is a chain of connected changes—food, people, markets, transport, money, industry, and trade—each making the next possible, and most of them centered in the south long before the court arrived there.

Act I: Rice and People

A Population That Doubled

Start with numbers. In 742, under the Tang, the government counted roughly 50 million people, a little fewer than the Han had counted in the year 2 CE. By 1102, under the Song, the population had reached about 100 million. China was by far the largest country in the world; it held more people than all of Europe combined.¹

Notice the dates. This was not a sudden boom in one emperor’s reign. The doubling took place over more than three and a half centuries, from the height of the Tang through the Five Dynasties and into the Song. It was a slow, cumulative change. Its foundation was food.

Why the South?

For most of Chinese history, the heart of the empire lay in the north, on the plains of the Yellow River, where farmers grew wheat and millet. The Yangzi valley and the lands south of it were warmer, wetter, hillier, and long more thinly settled. Over the centuries after the Han, and especially after the An Lushan rebellion of 755, more and more people moved south. By Song times the balance had tipped. The economic center of China lay in the Yangzi region.

The textbook points to three geographic advantages. First, the south grew rice, and rice yields more calories per unit of land than wheat or millet. The same field can feed more people. Second, the milder southern climate often allowed farmers to grow two crops on the same land in a single year, one after another—rice followed by wheat or vegetables, for example. Not every farm did this, and not every year produced two rice harvests, but the possibility mattered. Third, the south was laced with rivers, streams, lakes, and canals. Moving goods by boat cost far less than hauling them overland by cart or on human backs.

The Emperor’s Seed Rice

The Song court understood the value of better rice. In 1012, after drought in the lower Yangzi, Emperor Zhenzong had officials bring seed of a fast-ripening rice variety from Fujian, where it had been introduced from Champa in what is now central Vietnam, and distribute it to farmers in the Yangzi and Huai regions. Champa rice ripened quickly and could tolerate drier conditions than older varieties. That let farmers plant land that had been too high or too dry for rice, and it made a second crop in the same year easier to fit in.

Seed was only one part of the change. Southern farmers built terraces on hillsides, drained marshes, enclosed lake shores with dikes to create new fields, and used water wheels and pumps to move water. Officials printed and circulated farming manuals. None of this happened all at once, and the north’s wheat and millet agriculture did not disappear. But step by step, the south became the most productive farming region in China.

Act II: Into the Market

Farmers Who Bought and Sold

Denser settlement changed how farm families lived. The textbook puts it simply: “Agricultural prosperity and denser settlement patterns fostered commercialization of the economy.” Commercialization means more and more buying and selling. In densely populated regions with many markets, farmers found that they did not have to produce everything themselves. They could sell their surplus and buy charcoal, tea, oil, and wine. In many places farmers bought grain and specialized in crops grown for sale: sugar cane, oranges, cotton, silk, and tea.

Imagine two households—an illustration, not real people. One lives on a hillside in Fujian, where the slopes are good for tea but poor for rice. It grows tea, sells it, and uses the money to buy rice. The other lives in a lowland valley, grows more rice than it needs, and sells the extra. Each household now depends on the other, and both depend on the boats and merchants that connect them.

It is easy to exaggerate this change. Rural households before the Song were not all perfectly self-sufficient, and Song farmers did not all become specialized commercial producers. Many families in remote areas still grew most of what they ate. What changed was the degree of market participation, especially in the crowded, well-watered regions of the lower Yangzi and the southeast coast.

Boats Everywhere

Specialized farming only works if goods can reach buyers cheaply. Commercial production created demand for transport, and that demand built a great system of inland and coastal shipping that gave work to shipbuilders, boatmen, porters, and sailors. Shipping, in turn, made specialization more practical. Each encouraged the other.

The scale impressed outsiders. Marco Polo, the Venetian merchant who traveled in China in the late thirteenth century, shortly after the Song fell, described the traffic on the Yangzi with amazement. He claimed to have seen some fifteen thousand vessels at a single river city. No one counted them, and Polo liked large numbers, but his astonishment is real evidence of how busy the river seemed to a visitor from one of Europe’s great trading cities.

Money That Did Not Weigh Anything

More trade needed more money. The basic Chinese coin was a round copper coin with a square hole, strung on cords in “strings” of up to a thousand. The late Tang government had stopped using bolts of silk as a supplementary currency, which raised the demand for coins still further. The Song minted them on an enormous scale. By the 1080s the mints were producing about six billion coins a year, many times the output of the Tang.

Copper coins are heavy. A full string of a thousand weighed roughly eight pounds, and a large business deal could require a cartload. So, beginning in late Tang times, merchants developed a solution: they left money or goods with a “deposit shop” and received a receipt, then traded the receipts instead of the coins. In Sichuan, where the local currency was made of even heavier iron coins, the practice developed furthest. Early in the eleventh century the authorities gave a small group of Chengdu merchant houses the right to issue these certificates. When some of them failed to honor their notes, the government took over the system and in 1024 issued the world’s first government paper money.

Notice the order: merchants invented the practice; the state took it over. Paper money was not a bank balance on a screen. It was a printed certificate of value, backed for a time by reserves and limited to fixed terms and regions. As we will see, the temptation to print more of it would later cause serious trouble.

Business organization grew more complex too. Merchants formed partnerships and joint-stock arrangements that separated the people who put up money from the people who managed the business. In large cities merchants were organized into guilds by product—rice dealers, silk dealers, and so on. Guilds set prices from time to time, arranged sales from wholesalers to shopkeepers, and served as the government’s contact when it needed to buy goods or assess taxes. These were not modern corporations, but they were sophisticated tools for organizing trade.

Iron, Coal, and Paper

Industry grew alongside commerce. According to one influential estimate by the historian Robert Hartwell, iron production reached about 125,000 tons a year by 1078, roughly six times the output of the year 800. Later scholars have questioned the figure, but no one doubts that output grew dramatically. Ironmakers first fueled their furnaces with charcoal, which stripped forests in parts of the north. By the end of the eleventh century, coke made from coal had largely taken its place—an early example of industrial growth pushing against the limits of natural resources.

Much of the iron went to the army. Armor was mass-produced in small, medium, and large sizes, and high-quality steel went into swords. Song engineers also experimented with gunpowder weapons, and in the twelfth-century wars with the Jurchens, defenders of besieged cities used gunpowder to hurl projectiles. Economic strength fed military production. As Lecture 1 showed, however, it did not guarantee victory.

Papermaking flourished as well, supplying books, government documents, wrapping paper, and paper money. Lecture 3 takes up what cheaper printed books did to education.

The City That Never Slept

The quickening economy produced great cities. When Song chose its capital in 960, it broke with tradition and passed over Chang’an and Luoyang. It chose Kaifeng, a city that had grown rich because of its location near the northern end of the Grand Canal, where grain and goods from the south arrived.

Kaifeng was not like Tang Chang’an. You may remember Chang’an from Chapter 5: a planned grid of walled wards whose gates closed at night, with trade confined to two official markets. Kaifeng had grown up around commerce, and shops and markets spread along its streets wherever business was good. Officials lived and worked among ordinary residents. By 1063 the night curfew had been abolished, and businesses in the entertainment quarters stayed open all night. The famous scroll Along the River During the Qingming Festival, painted by Zhang Zeduan in the early twelfth century and usually thought to show Kaifeng or a city like it, is crowded with boats, bridges, shops, inns, porters, and peddlers.

Song court painters sometimes turned to such ordinary scenes. In paintings known as The Knick-knack Peddler, a traveling salesman carries hundreds of small items on a shoulder pole—toys, tools, bowls, charms—while a woman and children crowd around him. The painting is not a sales record. It shows how people at the time imagined commercial plenty: many small goods and eager customers.

Act III: Trade Across Every Border

Selling to the Enemy

Remember the silver and silk Song paid to Liao, Xia, and later Jin? Much of it came back. The payments gave Song’s rivals the means to buy Song products, and Song set up supervised markets along its borders to encourage that trade and collect tariffs—taxes on goods crossing the border. Song exports usually far exceeded its imports, so a large share of the silver sent north returned as payment for Chinese goods.

The goods going north included tea, silk, copper coins (widely used as money outside China), paper and printed books, porcelain, lacquerware, jewelry, grain, and ginger and other spices. Coming south were some of that silver, camels and sheep, and goods that had traveled the Silk Road, such as fine Indian and Persian cotton cloth, gems, incense, and perfumes.

Above all, Song needed horses. China’s farmland could not raise good cavalry horses in large numbers, and a state facing mounted enemies could not do without them. Liao generally forbade selling horses to Song, so Song bought most of its warhorses from Tibetan and other peoples along its northwestern frontier. From 1074 the government ran a monopoly that traded Sichuan tea for horses on that frontier. Trade did not end the rivalry. Military competition and economic exchange simply went on side by side.

Turning to the Sea

The most dramatic change came on the water. During the Song, for the first time, more of China’s foreign trade went by sea than by land. With the overland routes to Central Asia blocked by Xia and later Jin, the southeast coast looked outward to the “South Seas”—the maritime world of Southeast Asia, linked to the wider commerce of the Indian Ocean.

The Song government actively courted this trade. In 987 Emperor Taizong sent envoys to Southeast Asian kingdoms to invite their merchants to China. The court set up Maritime Trade Offices in the major ports—Guangzhou first, then Hangzhou, Mingzhou (modern Ningbo), and later Quanzhou—to register ships, collect duties, and buy imported goods for the state. Foreign merchants, many of them Arabs and Persians, lived in their own quarters in Guangzhou and Quanzhou, with their own mosques.

Chinese ships, in turn, sailed in growing numbers throughout Southeast Asia and into the Indian Ocean, where Chinese junks competed with Indian and Arab merchants and in some waters displaced them. The leading export was porcelain. An early twelfth-century writer reported that ceramics were the most common goods ships carried, and shards of Song porcelain have been found as far away as the coast of East Africa. Coming back were spices and aromatics—pepper, incense woods, frankincense, myrrh—along with pearls, ivory, and cotton cloth.

In 1225 Zhao Rukua, an official who supervised maritime trade at Quanzhou, wrote A Description of Foreign Peoples, an account of the lands Chinese merchants traded with and what they produced: pearls from the Persian Gulf, ivory from Aden, myrrh from the Somali coast, pepper from Java and Sumatra, cotton cloth from India. Zhao gathered most of his information by questioning merchants in port; he did not visit these places himself. And a product’s place of origin does not prove that Chinese ships sailed there. Goods passed from hand to hand through connected markets. Song expanded old ocean networks. It did not invent them.

The Best Ships in the World

What made Song ships able to carry so much? The textbook summarizes: “Chinese junks were larger than the ships of most of their competitors, such as the Indians and Arabs, and had many technical advances, including waterproofing with tung oil, watertight bulkheads, sounding lines to determine depth, and stern-mounted rudders for improved steering.”

Each feature solved a problem. Large hulls carried more cargo. Tung oil sealed the wood against water. Bulkheads—the wooden walls the Quanzhou ship still had—divided the hull into compartments, so that water entering one could not flood the whole ship. Sounding lines, weighted ropes lowered over the side, measured the depth of the water near coasts and shoals. A rudder mounted at the stern made a big ship easier to steer. Some ships used both oars and sails and could hold several hundred men.

Then there was the compass. Chinese people had known for centuries that a magnetized needle points north, but the Song made that knowledge practical at sea. Needles were made smaller and mounted in ways suited to shipboard use—floating in a bowl of water or, in some later Song designs, balanced on a pivot. The first clear description of a compass used for navigation at sea appears in a book completed in 1119, which reports that on dark or cloudy days sailors steered by the needle. The Song achievement, in other words, was the use of the compass at sea, not the discovery of magnetism. None of these advances removed storms, shipwreck, or pirates. They made long voyages more practical.

Profit and Risk

Technology explains how merchants could sail. Incentives explain why they did. The demand for imported goods in Chinese cities was huge, and the profits could be enormous. The risks were enormous too. An early twelfth-century writer explained that ships had to be large and carry hundreds of sailors for two reasons: to fight off pirates, and to carry enough cargo to still make a profit after paying substantial “gifts” to the authorities at every port.

Investors protected themselves by spreading the risk. They usually divided their money among several ships, and each ship had many investors. If you put everything into one ship and it sank, you were ruined; if you held shares in five and one sank, you kept most of your stake. One Song observer complained that coastal people were so eager to invest in overseas trade that they were draining copper cash out of the country. They gave merchants money to buy foreign goods, he wrote (as quoted in the course textbook), and “regularly make profits of several hundred per cent.” His complaint tells us what people expected and believed. It does not mean every investor got rich.

Act IV: The South Carries the Dynasty

Hangzhou, City of a Million

After 1127 the Song court settled at Hangzhou, at the southern end of the Grand Canal, a natural center for trade. The city grew to a million people or more, one of the largest cities in the world. Southern Song writers who described it, including the author of a guide to the capital’s wonders written in 1235, give a picture of an urban consumer society. Entertainment quarters were crowded with fortunetellers, acrobats, puppeteers, storytellers, tea houses, and restaurants. Catering companies supplied food, tents, tables, chairs, and decorations for banquets. Better-off residents formed clubs: the 1235 guide lists a West Lake Poetry Club, a Buddhist Tea Society, an Anglers’ Club, an Antique Collectors’ Club, and more.

City life created new problems, and the government took on new responsibilities. Crowded wooden buildings burned easily, so the state stationed two thousand soldiers at fourteen fire stations in the city. Poverty was harsher in a crowded city than in the countryside, so the government distributed alms and ran public clinics, homes for the elderly, and graveyards for the poor.

Prosperity was uneven. Brokers in the city offered girls and young women for purchase or hire as maids, concubines, singers, or prostitutes. The wealth of Hangzhou rested on a great deal of labor by people who shared little of it. Lecture 3 returns to family life and the lives of women.

How Southern Song Survived

Now the puzzle can be answered in three parts.

First, geography and production. Because the economic center had already shifted south, losing the north did not ruin the Song economy. The rice fields, waterways, and markets of the Yangzi region were already in place when the court arrived.

Second, people and commerce. Southern Song kept about 60 percent of the population, along with much of the most productive farmland and active urban and maritime markets.

Third, revenue and its limits. In the textbook’s words, “The government still had to devote a large part of its revenues to defense, but it was able to raise much of its revenue through taxes on commerce.” Taxes on trade, on goods in transit, and on state monopolies such as salt and wine, together with duties on the maritime trade, gave the court money that did not depend on farmland alone.

The limits were real. Defense remained enormously expensive. And the government increasingly paid its bills by printing paper money. Southern Song’s main paper currency, first issued in the 1160s, was printed in ever larger amounts in the thirteenth century, and prices rose sharply. That inflation came from specific policy choices under wartime pressure. It does not mean paper money by itself causes inflation, and the textbook does not explain every mechanism.

Epilogue: The Last Voyage

The southern economy carried Song for a century and a half, but it could not carry it forever. In the 1270s Mongol armies, now masters of north China, pushed down the Yangzi. Hangzhou surrendered in 1276. In Quanzhou, the superintendent of maritime trade, Pu Shougeng, a man of Arab or Persian descent whose family had grown rich in the sea trade, went over to the Mongols. The last Song loyalists were defeated at sea in 1279.

Somewhere in those final years the Quanzhou ship sank in Quanzhou Bay with its incense wood and pepper still aboard. The trade it served did not die with the dynasty. Under the Mongols Quanzhou grew busier still, and Marco Polo described Hangzhou, which he called Quinsai, as the finest and noblest city in the world. The economy the Song had built outlived the Song.

Closing Synthesis

The story can be held together with a handful of anchor dates and numbers. Population rose from about 50 million in 742 to about 100 million in 1102. In 1012 the court distributed Champa rice. In 1024 the government issued the first state paper money. Iron output may have reached 125,000 tons in 1078. In 1127 Song lost the north but kept about 60 percent of its people. In 1225 Zhao Rukua described the lands of the sea trade. Around 1277 the Quanzhou ship went down.

The numbers matter because they mark links in a chain. Rice and southern geography increased the food supply. More food supported more people, and denser settlement supported markets. Markets needed transport and money, so shipping expanded and merchants, and then the state, created paper currency. Industry grew with civilian and military demand. Trade crossed land borders to Song’s rivals and sea lanes to Southeast Asia and the Indian Ocean. And the south’s resources and commerce carried the dynasty after 1127.

Historians have debated how to describe this transformation. Mark Elvin called it a “medieval economic revolution,” and Japanese scholars such as Shiba Yoshinobu documented the spread of markets and commerce in detail. More recent work, such as Richard von Glahn’s, stresses that the change was uneven—concentrated in the lower Yangzi and the southeast coast—and that it was not an industrial revolution of the modern kind. Both points matter. Song China was transformed, and the transformation had limits.

That returns us to the framing question. How could Song lose its northern capital and still sustain a prosperous economy? Because its prosperity was never located in the capital. It lay in the rice fields, rivers, markets, workshops, and ports of the south—a connected economy that had been growing for centuries and that kept the dynasty alive, even though it could not keep the dynasty safe.

Notes

Chinese population figures come from government registers, not modern censuses. Officials counted households for taxation, and the numbers depended on how thoroughly they could register people. The Tang register of 742 lists about 49 million people. Song registers counted households more reliably than they counted individuals, and the figure of about 100 million for 1102 is a modern estimate built on the roughly 20 million households the government registered around that time, multiplied by an assumed household size. Historians argue about the exact numbers, and registration could rise or fall for reasons that had nothing to do with births and deaths—when the state lost control of a region, or when families hid from the tax collector, the totals dropped. The broad trend, however, is not in doubt: China’s population roughly doubled between the mid-Tang and the early twelfth century, and most of the growth took place in the south.

The same caution applies to other Song numbers in this essay. The iron estimate of 125,000 tons for 1078 comes from Robert Hartwell’s reconstruction from tax records, and later scholars, including Donald Wagner, have questioned how it was derived. Coin output figures come from official mint records. Marco Polo’s fifteen thousand ships were an impression, not a count. Numbers like these are best read as evidence of scale and direction, not as precise measurements. ↩