The Real Impact of the Silk Road | Extra Long Historical Documentary

[dramatic music] male narrator: Eurasia. The world's largest land mass. Some 10,000 kilometers from the Pacific to the Atlantic oceans. A formidable distance, even in today's world. And yet over that vast distance, human beings have pursued one of history's greatest enterprises. The Silk Road. A tremendously profitable trade route and so much more. For thousands of years, exotic goods, new technologies, conquering armies... [shouting] And brilliant ideas traveled along the Silk Road. [shouting] Silk Road trade helped to build empires and to break them. It fanned the fires of revolution... [booming] Drove great explorations, and forged powerful bonds between

faraway peoples. - The Silk Road made human beings realize that there are other people out there, and it opened the eyes of the east and the west. narrator: This is the story of how Silk Road trade made so much more than money. It's the epic tale of how the Silk Road helped create a world; a world that created us. 2,000 years ago, the Roman Empire seemed unstoppable. Rome had conquered much of Europe and was sending its legions beyond the eastern Mediterranean to the Middle East-- gateway to the riches of Asia. But a journey to the

east could become a road of blood. In 53 B.C.E. near the Mesopotamian town of Carrhae, the Parthians-- and empire blending Persian and Greek cultures-- confronted a Roman army. The outcome of the battle seemed beyond doubt. Some 40,000 Romans faced only 10,000 Parthians. And Rome's Legions were Europe's finest foot soldiers. [chanting] There was just one problem. The Parthian army didn't fight on foot. - The Parthians, they were cavalry. They were horse archers. Versatile. Rode like the wind. What the Romans did was what the Romans always did. They took a fixed position. They were ordered into a

hollow square defending all sides. But that was nothing to the Parthian horse archers because they could just ride around them, and they did. They galloped around and around and around and around, shooting as they went. [shouting] Thousands and thousands of arrows loosed into those Romans. [shouting] What the Romans eventually did was they were ordered to go into testudo. That's that Roman formation where they lock their shields together and put the next layer of shields to make a roof. Testudo is Latin for tortoise. But the Parthians had the answer to this tortoise. They had a hammer

to break open its shell. narrator: The Parthian hammer was a cataphract-- a Greek word meaning clothed in full armor. Horse and rider wore heavy coats of mail. The cataphract was the ancient world equivalent of a battle tank. At Carrhae, charging cataphracts broke open the testudo... [shouting] Exposing the Romans inside to more arrow attacks. Some 30,000 Romans were killed or captured. Parthian losses were minor. It was one of Rome's worst military defeats. But it may have been something else as well. A Roman historian wrote that the Parthians dazzled the Romans with banners made of a beautiful

fabric--silk. That may only be a legend. But around the time of Carrhae, Romans began coveting Chinese silk, and China began selling silk to Rome in exchange for fine Roman glassware and gold... Inspiring the name we give Eurasian trade today-- the Silk Road. But long before Romans and Parthians fought at Carrhae, trade between the peoples of Eurasia were shaping lives, making new things possible, and changing the world. At Carrhae, the Parthians won with a style of warfare that had evolved centuries earlier and thousands of kilometers away. On the steppes of Central Asia... An ocean of land...

Where victory in battle, and life itself, depended on moving very far, very fast. Thousands of years before the battle of Carrhae, a transportation revolution took place on these vast plains. - There's good evidence for, uh, the existence of domesticated horses in what is today Kazakhstan and southern Russia by 3500 B.C. And we actually think that probably horses were domesticated and began to be ridden 500 or maybe 1,000 years before that, maybe as early as 4500 B.C. [horses whinnying] narrator: The domestication of the horse was the first step towards cavalry warfare. But the second step would

be a long time coming. - The first use of horses in warfare was with chariot warfare, and we have that well established-- Tutankhamun's chariot, uh, which many people have seen in museum exhibits. And we know that people were using chariots in warfare starting in the Near East in about 16000, 17000 B.C. Horses were not used as organized cavalry until after about 900 B.C., almost 1,000 years after chariot warfare began. And it's always seemed odd to me that cavalry began after chariotry. Chariotry is very difficult to manage. You have to train horses to work together. They

have to pull this clumsy vehicle that has two people in it-- a driver and a warrior. Training the units to work together, very difficult thing to do, whereas jumping on the back of a horse is an easy thing. So why did cavalry come after chariotry? I think the real reason that, um, cavalry waited is that, uh, you needed to have really three innovations. The earliest evidence for the recurved bow is in Shang Dynasty, China, probably dated between 1300 and 1100 B.C. narrator: Shang emperors communicated with their ancestors by heating animal bones or turtle shells until

they cracked and then interpreting the patterns made by the cracks. One of these so-called oracle bones is carved with the Chinese character for bow--the earliest known image of a recurved bow. And in the tomb of Lady Fuhao-- and imperial consort and renowned military commander-- archaeologists found more evidence. - It's a thumb cover for drawing bow string and there's another piece that went in the middle of a recurved bow, a hand grip. The bows themselves are not preserved, so it's a difficult thing to identify the origins of the recurved bow. The different components of it probably

came from different places geographically. narrator: Just how far the recurved bow traveled across Eurasia was revealed in 2005 at Yanghai in China's Xinjiang region. Wooden bows rarely survive burial in the ground, but Xinjiang's cold, dry climate preserved one in a 3,000-year-old tomb. Other grave goods and the human remains found in the Yanghai tombs confirmed that the bow was made by the Scythians--a highly sophisticated culture that originated in southern Russia and migrated on horseback across the length and breadth of Eurasia. The true birthplace of the recurved composite bow remains an archaeological mystery. But there is no

doubt that 3,000 years ago anyone who fought on horseback would have found it revolutionary. - A bow is as strong as it is long. It derives its strength from its length. And the recurved bow packs the same length into this very short bow that can be swung over the horse's rear and over the horse's neck. And it was much, much easier to use on horseback. And the recurved bows are technologically quite difficult to make. It took a long time to develop the craft of bow making to that point. - The recurve are all these sinewy

bends-- reflex and deflex, that gives it in-built spring. But that can only be created with composite materials. What we mean by that is it's made of a number of materials. The heart of it is wood, usually beech. And then you have horn-- horn from a water buffalo, and then sinew-- the tendons of an animal. That, when you bash it, you can tease apart and get these very fine fibers-- fibers with tremendous tensile strength. That has elasticity and spring, and it stops the bow bursting apart. These are all materials that enhance the power, the spring, of

the bow. narrator: But only if bow makers could solve a very big problem. How to keep such a powerful bow made from so many different materials from breaking up when its own power was pulling it apart. Somewhere in Eurasia, sometime long ago, some unknown genius discovered the answer. - This is the swim bladder of a sturgeon-- fish from the Black Sea. And if you start to break these up then put it in hot water, and you get this wonderful, viscous glue. This simple idea of making a glue out of a swim bladder of a fish

was a technological breakthrough of immense consequences. It is what enabled the composite bow to exist. And in turn the composite bow was a military revolution of far-reaching consequences. narrator: The composite recurved bow gave birth to a new kind of warrior-- the horse archer. - The horse archer was able to shoot from the saddle in part because of the new technology of the composite bow. They were short, compact bows, and that meant that you can shoot them from horseback. You see I can cross to the other side of the horse. I can turn and shoot behind.

It's much more suitable for shooting on horseback. [dramatic music] narrator: Everyone who fought with Eurasian nomads, whether as enemy or friend, wanted a recurved composite bow. By the early first millennium B.C.E., it was in use from east Asia to eastern Europe. A recurved bow gave a horse archer unprecedented killing power. But it didn't make him a cavalryman. Before horse archers could fight as an effective military force, they needed a large supply of identical arrows. And that didn't exist. - Arrowheads were a variety of different sizes and weights. Some were made of bone. Some were made

out of flint. Some were made out of bronze. All of them would be individually made and you had to adjust your shot for the weight of different arrows. Also a unit of soldiers who were firing at the same time would be firing arrows of slightly different weights and they might go different distances. [dramatic music] - One of the technological innovations was the invention of the socketed, uh, arrowhead. They were made of bronze, usually, and, uh, they were made in a mould and cast in a mould, so that an infinite number of socketed arrowheads of the

same weight could be made from the same mould. Making socketed projectile points was actually a big deal. You have to have a mould with a core where the socket is going to be that you can pour molten metal around so that it's the same thickness all the way around. narrator: Making arrowheads of the same size and weight was another Central Asian technological revolution. For the first time, mounted warriors could unleash coordinated arrow attacks on their enemies. - With arrowheads of the same weight, every time you drew the bow to shoot, you knew that you were

firing an arrow that was exactly the same weight as the last arrow that you fired, uh, so you could determine the range and the distance well. And also all of the archers that were firing were firing arrowheads at the same weight at the same time. So the distance for all of them would be the same. narrator: Archaeologists believe that sometime in the second millennium B.C.E., socketed bronze arrowheads began spreading east while the composite recurved bow spread west. [dramatic music] Sometime around 900 B.C.E., socketed arrowheads and recurved bows met in the Tarim Basin area of Central

Asia, brought together by traders, warriors, and migrating nomads. - After about 700 B.C., you begin to see really thousands and thousands of arrowheads and dozens of arrowheads in a single quiver in a grave. It's like they're being mass produced. narrator: Bronze socketed arrowheads turned central Asia into an arsenal, but cavalries still couldn't exist until warriors could become soldiers. - It was really the age of heroic warfare-- individuals going out and doing great deeds by themselves and attracting glory for their own name, and this is the kind of warfare that's described in the "Iliad" the "Odyssey,"

uh, or in the "Rigveda," a religious text that's at the deep roots of modern Hinduism. What had to change was a psychological change in the nature of the warrior. You had to change from individuals to units working under the command of a commanding general, who would attack and retreat upon command. The psychological change from the heroic warrior to the soldier, uh, probably is a feature of urban warfare-- the armies that were associated with the great cities of Mesopotamia and Iran. That psychology had to spread northward up into the steppes and be accepted by warriors in--in

the steppes, uh, in the same area where the recurved bows and the socketed arrowheads were crossing. narrator: While recurved bows were spreading west and socketed arrowheads were spreading east, the concept of military discipline was spreading north. Sometime around 900 B.C.E., all three combined in the heart of central Asia. - When those three things came together, cavalry became a really deadly form of military force. narrator: A force that would severely test the ancient world's most powerful armies. 2,000 years ago, as the Romans pushed east to expand their empire, China was pushing west. And like the Romans,

the Chinese encountered a formidable enemy on horseback. The Xiongnu were nomads from the Central Asian steppes. Armed with recurved bows and socketed arrows, they fought under commanders as a disciplined military force. [shouting] They raided Chinese villages and plundered the growing trade between east and west, and no one could stop them. - The Xiongnu was the migraine of the ancient world for the Chinese. They simply just kept coming, and they would not stop. The Xiongnu wanted the finest material goods produced by the Chinese. [horse whinnying] [shouting] That is why they raided. - Imagine you're a villager

in China and these men come from nowhere. They come from over the hill without warning tearing into your village. They shoot the headman. They shoot your husband. They chase the women out. There is no hiding place, and there's a flurry of dust and arrows. They're in and they're out and they take the stuff and they go. [shouting] narrator: China sent its military might against the Xiongnu. The famed Terracotta Warriors reveal the size and power of Chinese armies. But the Chinese fought on foot and from chariots. Not effective against hit-and-run cavalry. A Chinese courtier wrote that

the Xiongnu moved like a flock of birds over the land, impossible to control. - Once mounted warfare really became deadly and effective, it became a real problem. If you're a farmer, the nomads know where you're going to be all the time. Your house is in the same place 12 months of the year, and when your crops become ripe, you have to harvest, and the nomads know when that season is. Whereas when you're trying to strike them back, it's impossible to know where they're going to be or when they're going to be there. You have to

search to find them. narrator: To beat the Xiongnu, the Chinese needed soldiers who could fight like them. They needed cavalry. - There are manuals of warfare that were written to instruct Chinese warriors on how to counter the tactics and the methods of the Xiongnu. Those manuals introduced the idea of cavalry to the Chinese military. The Chinese military had not really used cavalry before about probably 350 B.C. - Chinese military at first with some resistance from the old aristocratic families said, "Well, my father fought on a chariot "and his father fought on a chariot "and I'm

gonna fight on a chariot in my long robes like my ancestors." narrator: But it wasn't long before Chinese warriors traded their traditional long, flowing robes for shorter tunics that didn't get in the way of fighting on horseback. - Eventually the practicalities forced them to get rid of their robes, to put on riding trousers, to learn to shoot the bow on horseback, and they, too, became a mighty horse archer force. narrator: Chinese cavalry became experts at shooting the recurved composite bow and a lethal Chinese weapon, the crossbow. While its cavalry trained, China agreed to Xiongnu demands

for payments of money and silk until the year 133 B.C.E., when Emperor Han Wudi refused to pay... And sent his army to attack the Xiongnu. [shouting] [horse whinnying] Chinese cavalry defeated the nomads. And China seized new territories in the steppes... Pacifying trade routes and opening new horizons. - On one hand we have this perpetual conflict in-- in Chinese culture would be the Xiongnu and the Han Chinese that created incessant warfare. On the other hand, it is this conflict that demolished physical boundaries. Even territory boundaries were constantly being pushed farther, pushed back between the two forces.

This was a stimulus for exchanges, for political changes, for new ideas, for artistic traditions. narrator: It was also a new era for the Silk Road. A fortune in Roman gold traveled east in exchange for Chinese silks. And the Central Asian kingdom of Kushan made its own fortune selling another luxury to China-- jade. Silk Road caravans passed through this border station on China's western frontier. So many of them carried Kushan jade that this station became known as the Jade Gate. Chinese aristocrats coveted jade for its beauty and something more. They believed that jade would keep them

alive forever. The ruling elite commissioned jade burial suits to preserve their bodies in the grave. - They believed that upon death all the orifices should be plugged in to preserve the spirit inside the person. And this notion of jade as a material with protective power in the afterlife is further enhanced by the fact that they built an armor made of thousands of pieces of jade. And of course if you're the emperor, your--your jade armor would be made from the finest jade from the western regions. narrator: During the Roman empire, Silk Road trade flourished as Chinese,

Persian, and Kushan armies kept the trade routes open across Eurasia. [dramatic music] China had leveled the battlefield with nomad raiders from the steppes. But Central Asian horse archers were about to carve their names on history. In the 4th century C.E., Europe was invaded by a Central Asian people whose name still evokes barbaric cruelty. [shouting] The Huns, who fought their way west, all the way to Rome. European peoples like the Goths and Visigoths-- the so-called barbarians-- fled before their onslaught, and sought refuge in Roman territory. When the Huns withdrew from the Roman world, those barbarian refugees

stayed. [shouting] And the rest is history. narrator: The western Roman empire was plunged into chaos as barbarian tribes, dissatisfied with their lot, rebelled against Roman authority, and weak Roman emperors failed to crush them. As Rome declined, migrating horse archers called the Avars carved their own country out of eastern Europe... Bringing with them another Asian military innovation. The stirrup. This Chinese statue from the fourth century C.E. is the earliest known depiction of stirrups. Some 300 years later, an Avar horseman was riding with these stirrups across Hungary. By the eighth century C.E., the stirrup had spread from

one end of Eurasia to the other and mounted warfare was entering a new era. - The importance of the stirrup relates to what kinds of weapons can you use from horseback, and it made it possible to use certain kinds of weapons from horseback that you couldn't use without stirrups. Those weapons are the long sabre. You have to lean over and absorb shock if you're going to use a long sabre in battle. And the stirrups allow the rider to absorb the shock of contact with a stationary target. The other big weapon that was possible with stirrups

was a seated lance held under the arm. You could stab somebody with the lance and then remove it riding past them without stirrups. But if you seated it under your arm and used the lance as a shock weapon, it would knock you off the back of the horse if you didn't have stirrups. So stirrups made it possible to use long swords and lances as shock weapons against stationary targets and keep your seat, and of course that made it possible to have really heavy mounted warriors. - Now the rider becomes a unit with the horse. He's

so anchored with his stirrups, anchored with this, and then with his long lance he becomes a single projectile unit. [dramatic music] Man, horse, saddle, lance, all locked together for the impact charge. This was the age of the medieval knight. [horse whinnying] narrator: A medieval knight's power came from combining the Asian stirrup and the ancient shock tactics of the Persian cataphract with a European invention-- articulated plate armor. [horse whinnying] Strong enough to protect the wearer from sword and lance thrusts while light enough to allow him to move freely on horseback and on foot. Heavy cavalry had

never been a more potent weapon of war. - Medieval mounted warfare could be warfare that generated a lot of force on the rider, high impact warfare. In that case, the mounted warrior is being used really as a shock weapon to strike the enemy. narrator: But even Europe's formidable mounted knights would be outfought by Central Asian cavalry that burst out of the steppes and changed the world. - The largest conquest empire that the Earth has ever seen was created by pastoral nomads from Central Asia. narrator: In the 13th century, the Mongols conquered as far west as

Poland and as far east as the Sea of Japan. Mongol armies combined the devastating shock tactics of horse archers with a highly sophisticated military organization. narrator: The Mongols have gone down in history as bloodthirsty killers, but they were also sophisticated, open-minded, often generous conquerors. They pacified the Silk Road. Trade between west and east flourished under this Mongol-enforced peace-- the Pax Mongolica. - Before the age of Pax Mongolica, banditry was a very serious problem for traders, for caravans, along the Silk Road. The reputation of Genghis Khan and his descendents created peace and safe passage along the

Silk Road because bandits were so afraid of the Mongol soldiers. - The Pax Mongolica, the--the, uh, control of, uh, trade and exchange that was made possible under the Mongols connected China with Europe and with the Near East in a really close way for the first time in world history, and that had a profound effect on the development of European civilization. narrator: Protected by the Pax Mongolica, and anxious for good relations with the Mongol empire, Europeans began traveling east as never before. Merchants, missionaries, and diplomats flowed east along the trade routes, bringing back popular Asian goods

like cloth and spices and tales of the wealth and wonders of the east. Some true, some fabulous, but all fascinating. From Europe to China, Silk Road trade spread new knowledge of far-away lands. - The Silk Road made human beings realize that there are other people out there, and it opened the eyes of the east and the west. narrator: The Italian cities of Venice and Genoa reaped huge rewards. Their merchants traveled safely throughout Eurasia and founded trading posts on the Black Sea to receive and pass on Silk Road goods. Their Silk Road profits funded magnificent art

and architecture. But their competition frequently plunged them into war with one another. In one of these wars, Genoa captured a prosperous Venetian merchant named Marco Polo. Imprisoned by the Genoese, Polo dictated the story of his Silk Road journey to China to a fellow prisoner. - [speaking Italian] narrator: Today, experts debate whether Marco Polo really visited China or was simply retelling stories he had heard from fellow Silk Road travelers. - [speaking Italian] But there's no debate that "The Travels of Marco Polo" was one of the most influential books in all of human history. It tantalized Europe

with tales of China's immense wealth and advanced civilization. - [speaking Italian] narrator: And years before Marco Polo was telling those tales in a Genoese prison... - [speaking Italian] narrator: A Chinese invention was making its way across Eurasia to the west. Something created centuries earlier when an experiment ended very badly. Ancient Chinese alchemists prepared potions of lead or mercury for their aristocratic patrons who believed that drinking these metals would help them live forever. Instead, those concoctions killed them or made them insane. Another deadly combination was sulfur heated with an organic nitrate found in soil throughout China,

known today as saltpeter. When alchemists experimented with this formula, it burst into flame, injuring the alchemists... [explosion] And burning down their laboratory. From that disaster was born a chemical mixture like none other. It may have failed as an elixir of immortality, but it would prove to be a potent agent of death. This Chinese Buddhist scroll dating from around 950 C.E. depicts demons surrounding a seated Buddha. One demon holds what the Chinese called a huo quiang, or fire lance. It's the earliest known image of a weapon powered by that deadly mixture of saltpeter and sulfur... Known

to history as gunpowder. [shouting] In the early 13th century, the Mongols attacked China's Jin Dynasty. The Jin Dynasty's army fought back with exploding gunpowder bombs. But as the Mongols conquered more and more of China, Han Chinese artillerymen joined their armies and marched west, bringing their gunpowder weapons with them. The Mongols attacked Russian and Polish cities with exploding fire bombs. [explosions] And Europeans found out the hard way what gunpowder could do. By the end of the 13th century, the formula for gunpowder was known as far west as England, and Europeans were inventing their own versions of

the new weapons. It wasn't long before this Chinese invention changed European history. On 26th August, 1346 near the village of Crecy in northern France, the armies of France and England prepared to fight. Mounted on their war steeds, encased in their armor, the flower of French nobility formed their battle line... [horse whinnying] While the English deployed a very different force. Thousands of expert archers. The French sent their higher Genoese crossbowmen to attack the English before French knights annihilated them. But the English king, Edward III, had spent years training his longbow men. And all that training was

about to pay off. [grunting, shouting] - Nothing like this had been seen on a western battlefield up to this time. The first time that a volley of arrows was unleashed by the archers at Crecy would have represented something completely new to many of those in the French army watching it. A cloud of arrows descending towards them. It would have been frightening, and of course the effects almost immediate. narrator: Showered by English arrows, the Genoese turned and ran, and according to Medieval accounts of the battle, they were also panicked by another English weapon. [explosion] - Giovanni

Villani, writing very soon after the battle, says in his chronicle that so loud and intimidating was the noise created by the guns that they thought God was thundering. [explosions] - The English guns cast iron balls by means of fire. They made a noise like thunder and caused much loss in men and horses. [shouting] - Noise like that would have been unprecedented to the soldiers on the battlefield. Nothing in their lives could have prepared them for a-- a bang of that size and accompanied by smoke and acrid sulfur smell, which would hang in the air. The

impact of which, of course, they couldn't see until men around them dropped. Not even professional soldiers like the Genoese would have experienced anything like this before in their lives. That would have been terrifying, and it's no wonder that they scattered and ran. - They turned and fled into the face of the oncoming French cavalry charge. The French cavalry were now coming onto the battlefield and they were appalled at these people they'd hired running away. And they cursed them and they rode into them, and as many Genoese fell to French hooves as they did to English

arrows and gunshots. And the French Knights, all 12,000 of them, double the size of the English army, they came charging down onto the English. [horses whinnying] And they, too, fell to the English arrows and the English gunshot, and they came again and again and again. 15, 16 times, they came. And their horses were ripped to shreds and the men were thrown from their horses. And those that weren't thrown, they had the opportunity that the dagger men rushed in and they brought these knights down. This was a moment in history where the world changed. It spelled

the beginning of the end for the Medieval knight. narrator: The Battle of Crecy has gone down in history as one of the earliest uses of gunpowder weapons on a European battlefield. [explosion] Some 500 years after it burned down a Chinese alchemist's workshop, gunpowder had become destiny's weapon of choice. After Crecy, it was only a matter of time until the fates of peoples and nations were decided by the gun. [gunfire] Within two centuries, Europeans would use their powerful gunpowder weapons to dominate the world. Creating empires that would evolve into today's global trading culture... Which binds people

together by commerce instead of the gun. But before Europe could embark on its empire-building adventure, its medieval social order would be shattered by a catastrophic event. One that would forge a new Europe in a crucible of horror. While guns thundered at Crecy, something else was spreading along the Eurasian trade routes. Something that would kill tens of millions of Europeans. An apocalyptic destruction of human life that would lay the foundations of the modern world. (Tense music) (Horses neighing) NARRATOR: At the Battle of Crécy in 1346, the English won an historic victory over France. Helped by a

Chinese invention that had travelled to Europe. (Hollering) NARRATOR: Gunpowder. (Yelling) (Dramatic music) (Horses neighing) NARRATOR: And in the same year of 1346, some 2,000 kilometres east of Crécy, another battle was taking place on the shores of the Black Sea. (Hollering) NARRATOR: A Mongol army had been laying siege to the Crimean port city of Caffa, a Silk Road trading post belonging to the Italian city of Genoa. NARRATOR: The Mongols were masters of siege warfare. But Caffa was still holding out after more than two years. Suddenly, the Mongol army was decimated. Not by Caffa's defenders, but by

an unknown disease. The Mongols quickly ended their siege. But before they left Caffa, they loaded their siege engines with the corpses of their dead and flung them over the city's walls, believing that the stench of death would kill the defenders. Medieval chronicles say that Caffa's defenders did die by the thousands, but not from the smell of death. (Tense music) NARRATOR: One year later, in 1347, the same disease that had killed the Mongols at Caffa was killing people in Constantinople. (Computer beeping) NARRATOR: By 1348, it was killing people across Western Europe. By 1350, it was killing

people as far away as Greenland. (Soft music) NARRATOR: And terrified Europeans had given it a name. NARRATOR: The Black Death. In just under a decade, from 1347 to 1356, the Black Death killed at least 25 million Europeans. One third of Europe's population. Today, most scholars believe that the Black Death was an outbreak of bubonic plague. that was transmitted to humans by infected fleas living on rats. And we believe that it spread across Eurasia by hitching a ride with armies, ships, and caravans along trade routes that were already ancient by the time of the Black Death.

Micro-organic travellers of all kinds have moved across Eurasia for thousands of years. A bio-migration that has had as big an impact on history as the more famous exchanges of new technologies and luxury goods. And as a recent discovery shows, tiny living things moving along the Silk Road brought life as well as death. MARTIN: We were putting together some new methods of looking for early agriculture, and for that we needed to do a--a survey of all the finds of early crops in Europe. When you looked at a map of all of Europe, then you could see

there were these Chinese crops in small numbers very early on in Europe. NARRATOR: "Very early on" was around 2,000 BCE, when a Chinese grain called broomcorn millet appears in the Eastern European archaeological record. MARTIN: The actual crop itself will--will decay or be eaten, but, uh, rather fortunately, if it's cooked and over-burnt, it turns to carbon. That will stay in the archaeological record for a long time. (Dramatic music) NARRATOR: In the Chinese province of inner Mongolia, archaeologists are studying the origins of broomcorn millet, one of the world's oldest domestic crops. NARRATOR: But it isn't clear just

how and why broomcorn millet travelled thousands of kilometres across Eurasia, through some of the world's harshest environments, all the way to Europe. Millet's long journey may have begun simply because it travelled so well. Millets are essentially cereals, but they're very small. And because they have very small brains, they're hardy and they're tough, and they can grow quite fast. Broomcorn millet, at a push, can get from seed to seed in 45 days. You can plant a seed in the ground and 45 days later, in the right conditions, you may have plants. That's incredibly fast. So if

you're moving around parts of Asia, where, on the one hand, there's a long winter, a short growing season, and you can't particularly rely on rainfall, then something that gets a move on in terms of its growth cycle is--is very valuable. (Horse chuffing) MARTIN: There are accounts of communities that are on horseback for quite a lot of the time and herding animals and so forth, but for that short-- short season of the year that millet grows in, uh, they can actually sow the millet on horseback, trample it in with the horse's feet, and then either leave

a few teenagers there to scare the birds off for a couple of months, come back two months later, and harvest the crops. (Dramatic music) NARRATOR: Millet was a highly mobile grain, but there wasn't any evidence of how it might have travelled from its home in northern China. NARRATOR: Until archaeologists found signs of millet cultivation around 2500 BCE in the foothills of the Tian Shan Mountains in central Asia. (Tense music) MARTIN: At that point we asked ourselves, "Well--well, what is it about these foothills?" You know, "Why the foothills?" Clearly, it's about water. If one travels across

the centre of Asia, one realizes why water is a key. And wherever you are in Asia, it can be very dry, of course. But if one goes uphill to those foothills, then one has somewhere where there will be streams running off the mountains and water. NARRATOR: Archaeologists found that around 1,000 BCE, millet farmers left the Tian Shan foothills and their reliable water supply and began moving into much harsher environments. MARTIN: We can, see, uh, if you like, the confidence of farmers spreading out from where the water is really safe to areas where you have to

know more about the water and the landscape and the geography, both into the steppe to the north and to the desert to the south. NARRATOR: Millet's local migrations may have linked it with the world. Migrating millet farmers in search of water may have settled near trade routes. And long-distance travellers would have chosen routes near reliable sources of food and water. MARTIN: I think very much those traders are definitely working through networks that are already centuries old. It's at least a millennium before you see something crystallizing that you can start calling the Silk Road. NARRATOR: Another

discovery has revealed that this ancient grain migration wasn't only from east to west. NARRATOR: Trading millet and wheat between China and Europe may have done much more than feed people. (Soft music) NARRATOR: It may also have enabled profound social change. MARTIN: Seeds germinate at one time of year and are harvested another time of year, and that's kind of hardwired into their biology. And so farming is a one-season activity, and there are things going on at other times of year. And during the second millennium BC, a number of societies are doing something which is quite radically

different, and that is putting more than one season in a single year. Crops like millet are really useful for that, in that if you are a western farmer, with wheat and barley fields reaching maturity during the summer and you think, "Right, with the same plot of land, "I want to increase production. "And so I want another crop after I've harvested the first crop." You can't do a long season, large-grain crop like wheat and barley again, so something that's short and sharp like millet you can tag on to the end of it and catch another season

before the winter's set in. (Soft music) Interestingly, when you get to China, it's the converse. You have this short season crop already there, and by rearranging your life, you can bring a long season crop such as wheat and barley in at that stage. So the implications are, with the same plot of land, you could basically get two harvests rather than one. So two sets of calories rather than one. It may release some of the community to not farm at all and occupy roles within cities, or as craftspeople, or leaders. (Dramatic music) MARTIN: If we look

at the second millennium BC, what we certainly see is at the same time as multi-cropping is there, then there are a lot of the community-- are not farmers, but instead metalworkers, or kings, or priests, or something else. And so what we see evidence of is multi-cropping allows a non-farming, uh, sector within the community. MARTIN: So what we have is a small, not very impressive-looking seed, but because of the way it grows and because of its biology, it has a massive impact in changing the productivity of the heartlands of western farming. So those western farmlands could,

in the same area, produce two crops rather than one, and that enabled a whole series of things that we associate with the word "civilization." (Soft music) NARRATOR: Finding Chinese millet in Europe and European wheat and barley in China suggests that long before the Silk Road, East and West were introducing one another to new foods, and that the movement of crops may have helped create the earliest east-west trade routes. And in the deserts of far western China, archaeologists have discovered another way living organisms could travel the Silk Road. This is Xuanquanzhi Relay Station, an archaeological site

near the town of Dunhuang, a major stopping point on the Silk Road. 2,000 years ago during the Han dynasty, Xuanquanzhi was a very busy and very cosmopolitan place. PIERS: It would be used for merchants, and it would also be used for government business. People could travel long distances knowing that there was somewhere they could stay and be refreshed and recover, change their horses, and then move on to the next relay station. The wonderful thing about the Xuanquanzhi trading post was that it's in a part of the country that is not built up now, and the

environment, very, very dry and often very cold in the winter, means that things are preserved there very well. So a lot of the things with-- inside that trading post have--have survived instead of decomposing. NARRATOR: Excavators were especially excited to find something that perhaps only an archaeologist could love. The 2,000-year-old equivalent of toilet paper. PIERS: In China, they wrote back in-- in the Han dynasty times how they would have a stick with cloth wrapped on the end for people to wipe themselves with, and there were quite a few of these sticks thrown into the latrine, as

if people discarded them in there when they'd finished. These sticks have been found at some other excavations in China as well, but what's great about this particular relay station is we still have the cloth wrapped on the end, and we still have the human faeces on. (Tense music) PIERS: So we scraped off the dried faeces from the cloth and took them to the lab. We found four different species of parasite in those who used this latrine. Two of the species are spread by faeces contaminating your food or your hands or your drink. It's roundworm and

whipworm. Another species was a kind of tapeworm that they probably acquired by eating raw or undercooked pork. And then, we found the really exciting find, which was the Chinese liver fluke. PIERS: This is a small flatworm that lives in eastern and southern China and in Korea. It can only survive in marshy, wet places. But here, we found it 1 1/2 thousand kilometres away from anywhere that has it in modern times. So it wasn't what we expected to find. It was brilliant that we could find it on the Silk Road. The liver fluke requires a lifecycle

where it passes through freshwater snails, and through small fish, and then, bigger fish. And if you cook the fish, then you don't get the liver fluke. But if you eat the fish raw, then it hatches out in your stomach, migrates through your body, crawls into the liver, and then develops there. There was no way that people in the area of this relay station could have caught it in that particular area because it was far too dry. There were no lakes. There were no freshwater snails and fish for them to infect. NARRATOR: The finds at Xuanquanzhi

have shown that humans could carry diseases long distances along the Silk Road. (Soft music) NARRATOR: Another discovery has revealed what could happen when they did. In 2009, German scientists began investigating a puzzling discovery in the Bavarian town of Aschheim. NARRATOR: The Aschheim mass burial was an archaeological enigma, but there was one crucial clue. The bodies had been buried during the 6th century CE. (Computer beeping) (Tense music) NARRATOR: In the 6th century, a terrifying illness called the Plague of Justinian ravaged the Eastern Roman Empire. NARRATOR: It killed 30 to 50 million people in Europe, Asia, and

Africa. Nearly half of all the people on Earth. NARRATOR: The Justinian plague arrived in Constantinople on ships from Egypt, but what the disease was and where it came from remained unknown. The team investigating Aschheim's mass burial hoped its bones might reveal the answer. NARRATOR: Studies like the Aschheim DNA project have concluded that 800 years before the Black Death, plague travelled the Silk Road and that centuries later, the Black Death followed in its path. (Tense music) NARRATOR: Most scholars now agree that the Black Death originated in central Asia and that it first reached Europe on Italian

merchant ships returning from the East. NARRATOR: The Black Death killed with incredible speed. Victims had only a week to a few hours to live. Entire towns and monasteries were wiped out, and no one knew what to do. PIERS: It may have spread about five miles a day, which is a lot faster than a lot of modern bubonic plague outbreaks. Whether it was because of the rate at which people fled from it that spread it faster than it might otherwise have been. And it certainly was something that had a dramatic effect on people in Europe. They

all wrote about it. They were all scared of it. (Speaking foreign language) (Soft music) PIERS: So they had some concept of contagion and the idea that the disease could be spread from one person to another, but they didn't know how. They had no idea about bacteria or the spread of microorganisms at that stage, so they hadn't worked out how a disease was spread. But they just realized that one person seemed to be able to spread it to the rest of their family, so they realized something must be happening there. (Tense music) NARRATOR: Baffled physicians consulted

the works of ancient authorities like Hippocrates, who lived four centuries before the birth of Jesus, and Galen, who lived two centuries after Jesus' death. (Tense music) NARRATOR: Hippocrates and Galen believed that illness was a result of an imbalance among four so-called humours: blood, phlegm, yellow bile, and black bile. PIERS: The theory was that if you had your four humours in balance-- your blood, your phlegm, your black bile, and your yellow bile, then you'd be healthy. If they came out of balance or if you had corruption of one of your humours, then that would make you

unwell. So the treatments that doctors used were largely based on their understanding of humoural theory. So at the beginning, they tried the normal treatments of dietary modification and bloodletting and baths and so on, but they had no effect. (Dramatic music) PIERS: They believed that bad vapours were coming up from the ground, making people ill, affecting their humours. They believed that a strong southerly wind was a bad thing that made a lot of people ill, That it was a combination of the alignments of the planets, because they believed in astrology and its effect on your risk

of disease. They really didn't have a structured medical approach to how to deal with it. It took everyone off guard. No one knew how to deal with it. The doctors were effectively powerless. (Indistinct shouting) NARRATOR: Some citizens attempted another cure. Jews in Europe suffered fewer deaths from plague. That may have been because they were socially isolated and practiced better hygiene than the general population. But surviving the Black Death cost thousands of European Jews their lives. All across plague-stricken Europe, the already age-old Christian prejudice against Jews exploded into murderous hatred. PIERS: They believed that people with

leprosy or Jewish people may have actually exacerbated the plague by poisoning people. So this is a sign of how panicked and how worried everybody was, that they were thinking of really quite bizarre kind of interpretations as to why everybody was becoming sick. (Indistinct yelling) NARRATOR: While mobs murdered Jews, physicians tried to stop the Black Death. When traditional theories of disease failed, they resorted to studying the disease itself. (Tense music) NARRATOR: They were desperate to understand what was causing the Black Death, how it spread, and how to treat it. Slowly, they found answers. PIERS: They tried

various treatments, but no medicines had any effect. But that's why they moved over time to trying to restrict the contact of people, burning the clothes of people that had died rather than giving them to other people. And they realized that the clothes and spread of people was an important way they could stop the spread of disease. So we have the introduction of concept of quarantine, where people weren't allowed to move from one area to another if there was a plague outbreak and also that when sailors in ships arrived in a port, they may have to

stay in a quarantined area for a certain number of days until they were found to be clear of the disease, and then they could move inland and actually go into town. NARRATOR: Over time, this new trial and error approach would spawn a medical revolution. Some 200 years after the Black Death, the brilliant physician Andreas Vesalius published meticulous studies of the human body that exploded ancient and medieval theories and gave birth to modern anatomy. Europe's battle against the Black Death taught lessons that helped create modern medicine. And even centuries later, the Black Death still has much

to teach. So this is a skull of a man who survived the Black Death and died in Cambridge in the later part of the 1300s. We know he survived the Black Death because we have a radiocarbon date that's shown when he died, and we know he was a fairly old individual. (Tense music) One of the things we're doing here is a project looking at the effect of the bubonic plague upon the British population, specifically in Cambridge. And what we're trying to find out is what are different about people who survived compared with people who died.

That way, we can work out how the Black Death really changed the population of Britain and what our population might have been like had half of us not died in the mid-1300s. And to do that, we're looking at the genetics, the height, the health, and many other aspects of the skeletons that we find who died before the Black Death and the ones who died afterwards so we can see the effect of this epidemic upon people in Britain. So what we're hoping to find out is what is different about the genes of the people that survived.

Did they somehow have a better resistance to bubonic plague than other people, or was it just mere chance as to who survived and who died? (Tense music) NARRATOR: Those who did survive led better lives as the greatest horror of their age gave way to a new era. NARRATOR: The Black Death had decimated Europe's workforce. Desperate for labour, the nobility had to compete for surviving workers by offering higher wages. (Soft music) PIERS: Over the next few centuries, we see a complete rebalancing in the population. So the poor hungry farmers who didn't have enough land were suddenly

in a different position. The farmers around them had died. Their income could go up because they could farm much more land. And so there was less poverty and famine among the farmers. NARRATOR: Opportunities increased due to the shortage of workers. Women could now be scribes and hold other jobs formerly reserved for men. The European middle class was born. The fact that we then had fewer people able to do manual labour means that not only did the price of their labour go up so then they had better income. It also means that there seems to have

been a number of inventions made specifically for labour-saving devices. We find the introduction of the spinning wheel. We find horizontal looms. We find fulling mills. We had blast furnaces, mechanized tools, and we have three-masted ships that could hold a lot more cargo for only a small number of more sailors, so it's a much more efficient way of trade. So over the next 200 years or so, we see big improvements in mechanization. And the fact that-- fewer people around meant that these things may have been invented because of the shortage of people following the Black Death.

(Soft music) NARRATOR: Newly affluent Europeans created a bigger market for exotic imported goods. (Indistinct chatter) NARRATOR: Especially for one faraway luxury traded since ancient times along the Silk Road. (Bright music) NARRATOR: Spices. NARRATOR: In the late Middle Ages, Asian spices like pepper, cinnamon, and cloves were highly valuable commodities. (Indistinct chatter) NARRATOR: In London, dockworkers' bonuses were paid with Indonesian cloves. In Venice, people bought houses with pepper. NARRATOR: Anyone brave enough to seek out spices could get very, very rich. And trading in spices meant travelling the trade routes between East and West. NARRATOR: Venetian merchants travelled

those routes and dominated the spice trade. Europe had to pay whatever Venice demanded. Venice became a fabulously wealthy city, while the rest of Europe grumbled and paid. (Soft music) Meanwhile, China was also making epic voyages to the spice lands and developing some of the world's most advanced maritime technology. During the 13th and 14th centuries, foreign visitors to China were awed by the size and sophistication of Chinese vessels. In the year 1345, the Moroccan traveller Ibn Battuta wrote of seeing massive ships that could carry a thousand men, the only ships big enough to make the long

journey from China to India. (Speaking Italian) NARRATOR: And Marco Polo told of sailing on a Chinese spice trading vessel in the year 1292 CE. The experience deeply impressed him. He claimed the Chinese ship he sailed on was capable of holding 5,000 to 6,000 baskets of pepper, a much bigger cargo than the spice ships of his native Venice could hold. And that his vessel was escorted by smaller ships that could carry a thousand pepper baskets. (Tense music) NARRATOR: Polo embarked on his journey from the Chinese port of Quanzhou, a place he described as teeming with hundreds

of vessels from China and from distant lands. But he didn't report his vessel's exact dimensions, leaving historians to wonder if he'd exaggerated the ship's size or even if he'd actually sailed on it. And then, in 1973, Chinese archaeologists found a shipwreck in Quanzhou Harbour. NARRATOR: The Quanzhou Ship was carrying rare woods from Java and Cambodia, frankincense from Arabia, even ambergris from Somalia. (Soft music) NARRATOR: It sank in the year 1277, just 15 years before Marco Polo visited Quanzhou. And its design and construction were remarkably advanced for their time, featuring watertight compartments and other innovations centuries

before Western vessels had them. NARRATOR: 35 metres long and 10 metres wide, the Quanzhou Ship could have been one of the smaller vessels that escorted Marco Polo's bigger ship. (Tense music) NARRATOR: And there's also evidence that very large Chinese trading vessels did exist. NARRATOR: This park in the Chinese city of Nanjing is built on the remains of a shipyard dating from the 14th century. When they excavated that shipyard, archaeologists found two giant rudder posts, each of them over 10 metres long. NARRATOR: Chinese records speak of giant treasure ships carrying trade goods on epic journeys to

faraway lands. Commanded by the distinguished admiral Zheng He, a Chinese armada called the Great Fleet made seven voyages between the years 1405 and 1433. From Liugiagang in China's Jiangsu Province, the fleet sailed on diplomatic missions to southeast Asia, the great Indian seaport of Calicut, Arabia, and along Africa's east coast, forging relationships that linked seaborne and overland trade. Over 300 ships carrying nearly 30,000 men sailed on the first of those expeditions. (Dramatic music) NARRATOR: Chronicles of those voyages claim that the largest of Zheng He's ships were over 130 metres long and over 50 metres wide. NARRATOR:

But marine engineers doubt ships that big would have been seaworthy. The American clipper ship "Great Republic" launched in 1853, was 102 metres long and 16 metres wide. In 1872, her leaking hull sank her in a hurricane. The "Wyoming," built in 1909, was 110 metres long. (Soft music) NARRATOR: Its extreme length made it structurally unstable in heavy seas. In 1924, the "Wyoming" sank during a storm. If Zheng He's treasure ships were as big as Chinese chronicles claim, they would have been as long and wide as the "Wyoming" and longer than the "Great Republic." NARRATOR: Whatever the

size of its ships, the Great Fleet deeply impressed maritime trading nations from Indochina to Africa. China seemed poised to dominate the coveted spice trade. But in 1433, Admiral Zheng He died. About the same time, the Chinese court began losing interest in long-distance voyaging, and Chinese seafaring entered a long decline. Scarcely more than 100 years after the Great Fleet's last voyage, the emperor declared overseas voyaging a crime, and it wasn't long before east-west trade suffered another blow. (Computer beeping) NARRATOR: By the middle of the 15th century, the once-mighty Byzantine Empire was in deep decline. The Ottoman

Turks, descendants of central Asian nomads, had conquered most of its territory. The Byzantine emperor ruled only his capital of Constantinople. (Tense music) NARRATOR: In the Spring of 1453, the Ottoman sultan Mehmed II laid siege to Constantinople. (Clamouring) NARRATOR: The city was defended by a mere 7,000 troops. Mehmed had an army of some 80,000 men, but Mehmed wasn't sure he would win. The city's massive walls had withstood sieges for a thousand years. Protected by those walls, Constantinople's defenders held out for weeks. (Clamouring) NARRATOR: But Mehmed didn't just have an army. He had a mega-weapon: a bronze

cannon nearly 10 metres long with a barrel nearly a metre in diameter and 20 centimetres thick. It's said it could hurl a 450-kilogram stone cannonball more than 1 1/2 kilometres. This behemoth and nearly 70 smaller cannon bombarded Constantinople's walls day and night, damaging them so badly that the Turks succeeded in taking the city. (Clamouring) (Soft music) NARRATOR: The fall of Constantinople was a devastating blow to Europe. Constantinople had been one of Christendom's oldest and holiest cities. Now it was the capital of a powerful Muslim empire renamed Istanbul from a Turkish word meaning "find Islam." From

their new capital of Istanbul, the Ottomans now controlled access to the Black Sea and the eastern Mediterranean. Europeans merchants were cut off from the Silk Road. For nearly 100 years, Europeans had been growing wealthier and more and more eager to buy Asia's luxury goods. Europe needed to find new routes to the East. (Tense music) NARRATOR: And within 50 years of Constantinople's fall, it would. At the Battle of Crécy and the siege of Constantinople... An ancient Chinese invention, gunpowder, had helped transform medieval Europe. (Soft music) NARRATOR: Now another Chinese invention and European innovation would help transform

the future. NARRATOR: Sometime in China's ancient past, some unknown person invented something new... (water running) NARRATOR: By pounding plants until they fell apart... (wet thudding) (flames crackling) NARRATOR: Then boiling them in water... (flames crackling) (water sloshing) NARRATOR: And then collecting the boiled plants on a screen and letting them dry, making what the ancient Chinese called "refuse fibre"... And what we know today as paper, an invention so influential that some believe the Silk Road should have been named for it. JONATHAN: I would call it the paper road, because I think paper was far more important than

silk, and that, you know silk is a very nice fabric. It's very strong; it's beautiful, lustrous, and stuff like that. But it didn't have the impact on world history, I would argue, that paper did. The Chinese believe that the court eunuch Cai Lun invented paper around the year 100 of the Common Era and started using it for writing then. Chinese archaeologists, however, have discovered examples of paper in the deserts of western China that pre-date this by several centuries, perhaps three centuries or even more. NARRATOR: The Chinese probably first used the new invention as a wrapping

material, while they kept writing the old-fashioned way, on strips of bamboo. JONATHAN: You can write so many characters on a strip of bamboo that's maybe 40 centimetres long, or you know, 12 inches. The problem is, if you want to write a novel, for example, or a long historical text, you need to have a whole pile of those bamboo strips and keep them together in order. So that becomes heavy. Paper, which is made from plant materials, from the cellulose in plants, can be made anywhere that plants grow. So you can make it virtually anywhere in the

world, out of virtually anything. NARRATOR: By the early centuries of the Common Era, China was using paper in all the ways we do now, even as facial tissue and toilet paper. And it wasn't long before it travelled West along the Silk Road-- a journey that began as a pilgrimage. JONATHAN: The transformation of paper into a writing material came just at the time that Buddhism was introduced to China. Buddhists of China were interested in finding the original writings about the Buddha and would travel to India to collect them. And so, it's thought that the Chinese Buddhist

monks and missionaries brought knowledge of paper and papermaking with them to India to collect these Buddhist scriptures and brought them back to China. NARRATOR: Chinese Buddhists travelled to India along the Silk Road, detouring around the Himalayas through China's western desert and turning the Silk Road oasis of Dunhuang into a magnificent Buddhist library. In a desert without plants, Dunhuang monks made paper from rope and rags and copied thousands of Buddhist texts they'd brought from India. Thanks to Chinese Buddhism and to paper's obvious usefulness for keeping commercial accounts, papermaking began to spread throughout Asia. As the Chinese

then disseminated Buddhism throughout East Asia, they took knowledge of paper and papermaking to such places as Korea, Japan, Vietnam. We know that this is certainly before the time of the Muslim conquest of Central Asia, which occurred around the year 700. NARRATOR: In the eighth century C.E., Arab armies fighting in the name of a new religion, Islam, thrust deep into Central Asia and clashed with Chinese forces. During the same century, the Arab world began making its own paper, something that's traditionally been explained with a story about an iconic victory of Arabs over Chinese. (swords clanging) The

Battle of Talas was a battle that took place between Muslim forces and Chinese forces in central Asia in 751. According to the historian Atha Al Abi who lived something like 250 years after the event, he says that at this battle, Chinese papermakers were captured and that is how Muslims learned about papermaking. It seems to me that this is a sort of nice but not terribly believable story. Why would papermakers have been in the Chinese army? It's not as if, when you needed a sheet of paper, then you said, "Please, make me a sheet of paper."

(swords clanging, men shouting indistinctly) NARRATOR: It's more likely that Arabs learned about paper by trading along the Silk Road and recognized its immense practical value. Middle Easterners could write on Egyptian papyrus, but they had to buy papyrus from Egypt. Paper they could make themselves. By the end of the eighth century, Arab papermaking was well underway. JONATHAN: The break-out moment for paper was when Muslim bureaucracy encountered it. NARRATOR: Those bureaucrats ran the Abbasid Caliphate, founded around 750 C.E. From their capital in Baghdad, the Abbasids ruled the greatest empire of its day. JONATHAN: The administrators of the

empire had responsibility to keep records about who was paid what, who owed what, who owned what, who had to do what. Less than a century of Muslims first encountering it in central Asia, they were already making it in the capital of the empire. NARRATOR: And they quickly began using paper for more than keeping records. In eighth-century Baghdad and across the Arab world, the availability of cheap paper made possible one of humanity's greatest literary eras. JONATHAN: Baghdad becomes a centre of learning where books are written, books are translated from other languages. People wrote books on every

possible subject, not only on words in the traditions of the Prophet, but also cookbooks, popular literature, science, astronomy, geography, translations of Greek books on mathematics, all sorts of subjects. And this explosion of learning has long been known, but it's never been appreciated that it was based on the availability of paper. NARRATOR: During the Middle Ages, an intellectual Golden Age flowered in Arab Spain. Muslim, Jewish, and Christian scholars collaborated to translate, teach, and preserve great works of science, mathematics, and philosophy. One story about the library of the Cordovan Caliphate in Spain in the year 960 or

970 or something like that says that there were 400,000 books in the royal library. Now, that probably is an exaggeration. So let's take a zero off it and say that there were 40,000 books, but that is still more than ten times the number of books that was in the largest university library in Europe, several centuries later. Because libraries in Europe were all on parchment and the libraries in the Muslim world were on paper. NARRATOR: Spain was probably where Europeans first encountered paper. But Italian merchants were also discovering it through long-distance trade. This is a time

when Christian merchants from Europe, from such cities as Pisa and Genoa, Venice, are travelling to the cities of the Muslim world such as Cairo and Damascus in search of exotic items, goods like spices and silks, and they undoubtedly encountered paper. Our first European use of paper would've been by merchants who had seen Muslims using this stuff and must have brought it back. NARRATOR: But at first, many Europeans were suspicious of paper. It seemed so flimsy compared with parchments made from animal skins. The Holy Roman Emperor Frederick II, for example, was familiar with paper but didn't

think much of its qualities for preservation or didn't know how long it would last, so he ordered all documents that had previously been copied on paper to be recopied onto parchment. Similarly, the Abbot of Cluny, Peter the Venerable, knew about paper but said, "Oh, it was really disgusting "that they made this stuff "from vile materials rather than the pure reeds of the riverbed," meaning papyrus, or the skins of--of pure animals. And he was worried that paper could be made from dirty or unclean things. NARRATOR: But Europe's growing middle class was not concerned with paper's cleanliness.

A single parchment book needed 200 animal skins and cost a fortune. And as it happened, geography had given Europeans the edge in mass-producing paper. (bell tolling distantly) (water sloshing) JONATHAN: The rivers in the Middle East tended not to flow fast enough to create enough water power, whereas the greater variability in European terrain meant that you could harness the water power more efficiently to make more pulp more quickly. Europeans also had a ready supply of linen rags. In the late Middle Ages, a new way of processing linen had been developed using something called the flax breaker,

which meant that there was a lot more linen being made from flax and made into people's underwear. (fabric ripping) JONATHAN: Linen underwear was lot more comfortable than woollen underwear because it didn't scratch, and so linen became very, very popular and became the source of rags for papermaking. NARRATOR: By the late Middle Ages, Italian hill towns like Fabriano and Amalfi had become Europe's leading paper manufacturers shipping tons of paper to businessmen throughout Europe. (machinery clanking) NARRATOR: And this mass production of cheap paper was changing Europe in other profound ways. One of the most interesting documents that

I've seen, or seen photographs of, is a poem by Petrarch, the Italian poet. It's on paper. And it is crossed out. He wrote out the poem and then he changed his mind and he put in a better word. So he was able to compose, in effect on paper, as opposed to composing it in his mind, repeating it over and over again until he got it perfect and then putting down a fair copy on the final expensive material. This is something you wouldn't do on parchment because it was too expensive. You'd have to scrape it off.

Paper allowed all sorts of new ways of doing things. It seems to me that it's no accident that the art of drawing really develops in the 15th century in Italy. JONATHAN: Paper allowed an artist to actually do a drawing and work out an idea in front of his eyes and preserve it for later use, or to look at it and say, "I'll change this; I'll change that." And save it and make a copy of the drawing. And we know that Michelangelo, for example, did drawings of his drawings or did drawings of other people's drawings. This

wouldn't have been possible with parchment because it was too expensive to waste in this way. NARRATOR: Meanwhile, in Asia, the country that had given paper to the world had developed a technology that had turned book production from a laborious job for scribes into a standardized process: Printing. In the ninth century C.E., the time of the Tang Dynasty, Chinese printers were printing book pages carved from a single block of wood. The world's oldest printed book is this Chinese copy of the Buddhist Diamond Sutra printed in the year 868 C.E. Some 400 years later, around 1300, Asian

woodblock printing had travelled the Silk Road to the West. But by then, China had invented a more efficient way of printing. Instead of carving a single wooden block into a book page, printers engraved pieces of clay with individual Chinese characters, baked the clay letters to harden them, and then arranged them in a frame to create a book page... The earliest known use of moveable type. And then, in the year 1440, Johannes Gutenberg, a goldsmith in the German city of Mainz, came up with a new way of printing. Gutenberg began with a screw press, a wooden

screw that pushed a plate down on a flat surface invented by the Romans to make wine and used in Gutenberg's time to make woodblock prints. He made his own moveable type by punching letters out of metal and casting them using a hand mould he'd invented himself. He devised a system for quickly composing lines of type in trays. And he invented a new oil-based printing ink that transferred easily to metal type. Gutenberg's new printing process was much faster and more efficient than Asian printing techniques. But its biggest advantage may simply have been this: The Latin alphabet.

JONATHAN: In Chinese you have many characters, and so you have to have like 6,000 individual characters in order to print something. In Europe, where you have the Latin alphabet with individual letters that are not connected to each other and you only have 26 of them and you have upper case and lower case capital letters and small letters, you don't really need that many to write out a text. NARRATOR: If ever a new technology re-wrote human history, it was Gutenberg's printing press. Within a few years of Gutenberg's first printing run, millions of Europeans were reading the

Bible and other best-selling books translated into their own languages, something we take for granted. But in 15th-century Europe, it was revolutionary. Working together, paper and the printing press had achieved something never done before. They had democratized knowledge. (speaking German) NARRATOR: Europe's new demand for books and its new ability to mass-produce books to meet that demand would soon have enormous consequences. In Germany, a firebrand monk named Martin Luther wrote a list of 95 proposals for reforming what Luther denounced as the corrupt practices of the Catholic Church. Thanks to paper and the printing press, his ideas spread

like wildfire across Germany and Switzerland. And so began the Protestant Reformation, a spiritual revolt that ended Catholicism's thousand-year monopoly of the European soul. And some other best-selling books helped an Italian living in Spain realize his dream. His name was Cristobal Colon, and he was deeply disturbed that the holy cities of Christendom had fallen under the rule of the Ottoman Turks. Colon drew up plans for a new Crusade to liberate Jerusalem. To fund it, he decided to travel to Asia to trade for spices and other luxury goods he could sell for a large profit back home.

NARRATOR: But the Ottoman Empire had blocked Europeans from the Silk Road. Colon needed to find a new route to Asia. His deep study of two books, "The Travels of Marco Polo" and the ancient Greek author Ptolemy's "Geography," convinced him that he could find Asia by sailing West across the Atlantic. And when he landed in the Americas in 1492, Colon, known to history as Christopher Columbus, was sure he'd found it. In fact, it wouldn't be until 1498 that the Portuguese explorer Vasco da Gama rounded Africa's Cape of Good Hope and sailed east to India, discovering the

true sea route to Asia. But the new world Columbus had given Spain proved to have riches of its own. By the middle of the 16th century, the Portuguese had established good trading relations with China in Guangzhou and Macau. And Spain's American colonies were sending so much silver home that there was hardly any room to store it. Spain was sending it on to northern Europe, especially the Netherlands, as payment for trade goods. Their pockets bursting with American silver, Europeans became addicted to two Asian luxuries. One was porcelain, an extraordinary ceramic made by firing a soft white

clay called kaolin at very high temperatures, well over 1,000 degrees Celsius. China had been making porcelain for export and trading it throughout Asia and the Middle East since at least the ninth century C.E. In the 17th century, the Dutch captured two Portuguese ships filled with porcelain and held a giant porcelain auction. It was the beginning of Europe's 300-year obsession with Chinese ceramics or, as they became known in Europe and America, "fine China." It was a status symbol for the West, and they had never seen anything like that before. But also, they certainly didn't know how

it was made. NARRATOR: Porcelain imports were indispensable to consuming another Chinese trade good craved by Europeans: Tea. Like porcelain, tea had been a profitable Chinese export since at least the ninth century to the Middle East but not to Europe. The Portuguese began trading for it in the 16th century. In 1657, a London merchant sold the first tea in Britain. By the year 1700, tea-drinking had become a British obsession heavily promoted by the British East India Company, which traded British textiles to China and needed a profitable luxury good to bring back to Britain. And as Chinese

tea began moving West to Europe, Europeans began trading exotic new foods to China. (children laughing) NARRATOR: In the 17th century, dozens of never-before seen food crops from the Americas-- potatoes, sweet potatoes, corn, peanuts, pineapples, chilies, and tomatoes-- began appearing in Chinese markets. Some of these new foods offered more than just the appeal of the exotic. Corn, potatoes, and sweet potatoes grew in harsh New World environments like the South American Andes. Chinese farmers soon discovered these hardy crops would survive the frequent droughts that wiped out many native crops starving large numbers of Chinese. It's no coincidence

that in the 17th century, after the introduction of drought-resistant crops, China's population began to grow and kept growing until China became the world's most populous nation. And the new sea routes brought even more to China from the West. An Italian named Matteo Ricci arrived in China in 1582 and spent the rest of his life there. Ricci was a Catholic missionary, and his mission to China produced one of history's most enlightened meetings of minds. Ricci learned to speak, read, and write Chinese, and formed deep friendships with Chinese scholars. One of Matteo Ricci's closest collaborators and first

converts to Catholicism was the mathematician Xu Guangqi. AGNES: My ancestor Xu Guangqi, who is known in Vatican history as Paul Hsu, met him around the time when he first came to China. And in 1603, my ancestor converted to Roman Catholicism. NARRATOR: Working together, Matteo Ricci and Xu Guangqi translated works from the ancient Greek mathematician Euclid and other classics of Western science and mathematics into Chinese. They also translated Confucian writings into Latin. Ricci wrote to his superiors in Europe, asking them to send more missionaries to China, but only their smartest men. In China, he wrote, "We

are dealing with a people both intelligent and learned." Xu Guangqi himself was an astronomer, a highly accomplished astronomer and a mathematician. But the introduction of Western science opened his eyes to a different way of thinking, a different way of approaching natural phenomena. NARRATOR: Matteo Ricci was a Jesuit, a member of the Society of Jesus, a new Catholic order founded on the principles of the European Renaissance. Jesuit priests were trained in science and mathematics as well as in theology. As missionaries, they respected other cultures and worked to integrate Christianity with non-Christian beliefs. From the 16th until

the 19th century, nearly a thousand Jesuits worked in China teaching everything from engineering to mathematics to geography and sending back translated classics of Chinese learning to Europe, giving Europe its first in-depth knowledge of Chinese civilization and China its first in-depth knowledge of the West. Chinese and Europeans became more and more fascinated with each other's civilizations. King Louis XIV of France sent French Jesuits to the mission in China. And Chinese emperors appointed Jesuits to important government positions. For more than 100 years, Jesuit astronomers directed the Imperial Astronomical Bureau. One of them, the German Johann Adam Schall

von Bell, helped create a new Chinese calendar that predicted solar and lunar eclipses with more accuracy. He also introduced his Chinese colleagues to a new European invention, the telescope. The Belgian priest Ferdinand Verbiest built an aqueduct, made European-style cannons for the army, and built a steam-powered vehicle for the emperor considered by some to be the world's earliest automobile. In 1674, Verbiest presented the emperor with a new map of the world. The collaborative product of European and Chinese knowledge, it was more than just a map. It was an expression of a new worldview. A worldview based

on science, exploration, and confidence in the human ability to discover, to invent, and to create a better world. A worldview that saw the world as one. Arguably the most famous scholar of that age is Voltaire. And in his essay "Sur le Moeurs" which was first published in 1756, he argued that China was the paragon of Enlighted monarchy ruled by intellectuals. It challenges the fundamental notion that the Christian European world was the beginning and the centre of civilization. China, in Voltaire's mind, was a civilization ruled by reason and ruled by men promoted through education... Through virtue,

and through their scholarly accomplishments, their merits; not by hereditary rights. (gunfire, faint shouting) NARRATOR: In Voltaire's time, Europeans were fighting their hereditary kings for the right to rule themselves. By 1800, political revolutions in Britain, America, and France had ended centuries of absolute monarchy. New technologies like the mechanical loom and the steam engine and the rise of industrial capitalism were connecting the far corners of the world. And an ancient Chinese invention that had spread westward centuries earlier was playing a critical role. (men shouting faintly, gunfire) NARRATOR: Gunpowder had made modern warfare possible. (cannon booms) (gunshot) NARRATOR:

And in mineral-rich areas like France's Vosges Mountains, it was helping in a different way to create the modern world. At the beginning of the 17th century, these mountains were honeycombed with mines and crowded with miners from all over Europe chasing rumours of riches underground. (Francis speaking French) (water dripping) NARRATOR: In the accounting books of the Thillot Mine, archaeologists discovered an entry from the year 1617 recording the purchase of gunpowder to do something revolutionary-- blast a mine tunnel from the living rock. (water dripping) (speaking French) NARRATOR: By the beginning of the 19th century, gunpowder was helping

European mining evolve from laborious hand digging to a modern enterprise, supplying Europe's growing industrial economy. And across the Atlantic, it was about to help a new nation unlock its vast economic potential. On July 4, 1817, the United States of America's 41st birthday, crews in New York State began digging the Erie Canal, a nearly 600-kilometre shipping channel designed to connect the Great Lakes with the Hudson River and the Atlantic Ocean so towns and farms on America's frontier could ship and sell their products worldwide. Most of the canal route lay in flat country, and the canal builders

had little trouble digging through soft soil. But 50 kilometres from Lake Erie, the landscape suddenly changed. By 1824, they got here, to Lockport. And what they encountered was a solid rock ledge of a very hard rock called Lockport Dolomite. 10 or 12 miles from here, there was more hard rock excavation than anywhere else in the canal system put together. This is the same rock that forms the lip of Niagara Falls. It's as if they were climbing the face of Niagara Falls in order to get canal boats past here and onto Lake Erie and the upper

Great Lakes. NARRATOR: Lifting canal boats from Lockport to the level of Lake Erie meant raising them 15 metres high. The only way to do that was by building a series of locks. But cutting those locks though dolomite with picks and shovels would have been next to impossible. You can chip away with chisels and picks, but it would've taken years and years and years to whittle down, to hew your way down through this rock. Without explosives, they weren't going any further. They weren't gonna reach their ultimate goal of Lake Erie; they weren't gonna be able to

open the Great Lakes to maritime commerce. They needed some way to move massive quantities of rock. NARRATOR: Using gunpowder instead of pick and shovel, the canal builders excavated the lock chambers in two years. But gunpowder's work was just beginning. As soon as the canal diggers reached the height of Lake Erie, they had to lower the channel below it so the lake would flow into the canal and keep it full of water. Behind me you're looking at the final challenge in Erie Canal construction. It's not terribly exciting looking. It's not like the locks. But this, cutting

this slot, the Deep Cut through four miles of rock was the last major challenge before the canal builders could get to Lake Erie and the one that took them more than a year to accomplish. The Deep Cut required them to cut a vertical slot through rock, something they hadn't encountered anywhere else on the entire canal construction project. They probably used more gunpowder, more explosives in these four or five miles than they used in the rest of the canal put together. (explosion) DUNCAN: Rock went all over the place. There are lots of stories about anything from

a pebble to a boulder raining down on the construction camp, this hail of rock every time they set off a charge. And the blasting went on day and night. (explosion) DUNCAN: Construction workers were killed in blasting. There were residents of the city who were killed, There are newspaper accounts of women being killed by falling rock while they were simply minding their business walking from one house to another. NARRATOR: By the end of 1825, the Deep Cut was finished and the Erie Canal was officially open for business. Before roads and railroads had penetrated the North American

wilderness, the Erie Canal made possible the westward economic expansion of the young United States. And the digging of the Erie Canal had another enormous consequence. It would play a key role in transforming the American seaport at its eastern end into the modern world's greatest city. The Erie Canal vaulted New York City from being one of several Atlantic ports competing with Philadelphia, Baltimore, and Boston to the head of the pack. New York became a world leader in maritime commerce, and all the other business activities that go along with maritime commerce, things like insurance and financing and

the grain exchange, that all happened in New York because the Erie Canal brought the produce of the interior of a continent to the Atlantic in New York harbour. NARRATOR: By the 20th century, New York had become the prototype of the megacity. Spawned and sustained by global trade, the megacity transcends its national roots and becomes a world city, encompassing human diversity. New York's evolution was the ultimate expression of forces that have been at work for thousands of years, set in motion and sustained by the East-West commerce of the Silk Road... A path through history that didn't

just link human beings together but shaped their fates. AGNES: The Silk Road was like a ray of light. It opened our eyes, East and West, to intangible ideas, to beautiful things, to beautiful thoughts. NARRATOR: Today, the ancient tale of the Silk Road seems like the story of an exotic past. But in fact, it's just as much a story of the future. Two or three times a week, a train departs from the Chinese city of Yiwu. It's loaded with Chinese- manufactured consumer goods, and its route takes it across six countries in Central Asia and Eastern Europe.

(train whistle blows) NARRATOR: It takes 18 to 20 days to reach one of several destinations in Western Europe, over distances of some 12,000 to 13,000 kilometres. Loaded up with European manufactured goods, it returns to China. The Yiwu Railway is pioneering the return of the Silk Road. On 14 May 2017, China hosted a conference in Beijing to promote its "One Belt, One Road" initiative. Attending were delegates from around the world, including the heads of the International Monetary Fund, the World Bank, and the United Nations and nearly 30 heads of state. Known as OBOR, One Belt, One

Road plans to build a $1 trillion U.S. dollar transport network that will connect some 60 countries, 2/3 of the world's population, and 1/3 of the world's GDP. Inspired by the Old Silk Road, it will re-establish the ancient trade routes overland and by sea. And it will also create a New Silk Road in space. On August 1, 2017, China's Tianzhou-1 cargo spacecraft released the nano-satellite SilkRoad-1 01 CubeSat into orbit. SilkRoad-1 is a pathfinder for a constellation of around 30 satellites operating across a variety of wavelengths. (rocket roaring) NARRATOR: These satellites will help build an efficient and

reliable satellite navigation system that will provide mapping and navigation services and remote sensing technology to all the cities of Western China and to other countries along the new Silk Road. (speaking foreign language) (rocket roars) (speaking foreign language) (Yang Liwei speaking foreign language) (Zhou Jianping speaking foreign language) NARRATOR: For thousands of years, the movement of goods, people, and inventions across Eurasia has played a critical role in shaping human destiny. And it may soon be helping to shape humanity's future.