Part 1 of 2
The Real Impact of the Silk Road | Extra Long Historical Documentary
Get.factual
Nov 17, 2024
The Silk Road stands as one of humanity’s most transformative endeavors, connecting East and West across Eurasia for thousands of years. This documentary series examines its profound impact on history, shaping empires, spreading ideas, and revolutionizing civilizations. Today's extra long history documentary explores how the Silk Road influenced conflicts, from cavalry tactics to the invention of gunpowder. It then reveals how the route became a conduit for both life and disease, reshaping societies. Finally, it uncovers the pivotal role of Silk Road trade in driving the Age of Revolutions and shaping the modern world.
Transcript
[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)