Original subtitles

Deep in the remote desert of Southern Iraq,

a team of archaeologists

hunts for traces of an ancient catastrophe.

Once I dig a small bit

we can find fossils here.

This is telling us that water was there.

Their cutting-edge aerial investigation

reveals an enormous canal network,

spreading almost 80 square miles.

One of the earliest ever discovered.

We have more than 4,000 canals.

Clues in this landscape could reveal the truth

behind one of the Bible's greatest mysteries...

Noah and the Great Flood.

The stories in the Bible are famous across the world.

They tell of great battles between good and evil,

earth-shaking catastrophes, and heroic characters.

Now, new archaeological discoveries buried in the Middle East for thousands of years

are shedding fascinating light on real events

that may have given rise to these legends.

Today, multi-national teams of archaeologists

are tracing the origins of the famous story of Noah's Great Flood,

an epic inundation which wiped the Earth clean.

These texts suggest that there was a flood thousands of years before the Bible story.

The Bible says that the flood happened

in an ancient land called Shinar, today, Southern Iraq.

Why did the Bible place this story here?

What evidence is there that this catastrophic event

really happened?

One hundred and fifty miles south of Iraq's capital, Baghdad,

lies the remote ancient site of Uruk.

Known as Erech in the Old Testament,

the Bible claims it was one of the first cities founded

after the flood.

Geo-archaeologist Jaafar Jotheri has spent over a decade exploring

this ancient metropolis and others in the region.

The thing that I actually enjoy most in my work

is discovering the landscape archeology.

You know, whenever I work, I discover a new thing.

Jaafar grew up on a farm nearby

and feels a close link with Iraq's ancient peoples.

Maybe we don't have a direct connection with people who lived here

but, you know, we share the same place.

We are representatives of these people

and it's a great pleasure, of course, a great honor.

The city of Uruk was founded

more than 5,000 years ago in around 3,500 BCE.

Jaafar wants to find out if an all-consuming flood

could really have happened here

before Uruk became a city, as the Bible says.

His first mission is to explore what Uruk looked like at this time.

It's hard to get a sense of these crumbling ruins from the ground.

They have disappeared beneath the desert sands

after thousands of years of erosion.

So, Jaafar turns to aerial archeology for answers.

He sends up a drone-mounted high-definition camera.

The drone can pick out the shape of many buildings

scattered across the landscape.

We can see lots of temples, houses and city walls here.

At the city's heart

lies the remains of one of its most impressive structures...

an enormous man-made mound,

a ziggurat.

We can see a ziggurat.

A beautiful ziggurat.

Everything is well-preserved.

Ziggurats are similar to huge, stepped pyramids.

Some towered over 100 feet high.

The oldest predate those in Egypt by several centuries.

Egypt's pyramids are giant tombs for the dead,

but these ziggurats were monuments topped with temples

dedicated to the gods.

Uruk belonged to a people called the Sumerians,

one of the world's first urbanized civilizations.

The Sumerians built large cities with a social hierarchy

and an organized administration at a time when most people lived

in small agricultural settlements.

This led them to create some of humanity's

greatest inventions in writing, law, and science.

The full drone survey reveals the scale of Uruk.

You can see here, it's a large city. A very large city.

One of the largest cities in Southern Mesopotamia.

In its heyday, around 5,000 years ago,

Uruk was the largest city on Earth with a population of at least 40,000.

It must've needed a huge supply of food

and, crucially, water.

But today, Uruk's ruins are dry and lifeless,

so where did the city get its water?

The Euphrates was running for a long time here.

This is the only source of water.

We don't have, let's say, groundwater or springs.

That's why people actually use the river to live.

The mighty river Euphrates is the longest in Western Asia.

It runs north to south through Iraq, along with the river Tigris.

Together, they were so important, the whole region was named after them:

Mesopotamia, "the land between two rivers."

Today, the Euphrates runs 12 miles to the west of Uruk,

but Jaafar believes that over thousands of years,

it changed course.

In ancient times, it ran right by the city.

In its prime, Uruk was an enormous metropolis.

By 2,900 BCE, it stretched over two square miles.

Holy priests worshipped at the city's main temple

on top of the ziggurat, the center of religious life.

Surrounding the city, a network of canals

brought fresh water from the river Euphrates,

irrigating vast areas of farmland to feed the citizens.

This ancient megacity relied on water.

Was there some catastrophe here, linked to the river,

that sheds light on the biblical story?

When you visit the city now

you can't imagine this city was a Garden of Eden, right?

But it was for more than a thousand years.

Jaafar hunts for signs

that the river Euphrates could be responsible

for an immense flood, thousands of years ago.

Ancient writing expert Lara Bampfield investigates long-lost texts

which tell of world-changing floods in the region's distant past.

Mesopotamia, as a whole, is definitely a source of inspiration

for a lot of biblical stories:

the Garden of Eden, Abraham, the Tower of Babel.

They all stem from Mesopotamia.

The Biblical story of the Great Flood

centers on a man called Noah,

who it says was 600 years old when the rains came.

The Bible's Book of Genesis tells how God warns Noah

that a flood will soon cleanse the earth of all the wicked people.

Noah builds a gigantic ark,

and fills it with pairs of every animal on Earth.

Hunkered in the ark, Noah and his family endure

the deluge for 40 days and 40 nights.

Finally, the waters recede,

and Noah's ark comes to rest on a mountaintop,

ready to create new life on Earth.

Biblical historians believe that Noah's story

is set around the mid-third millennium BCE,

but Genesis is not the only ancient text to record a flood story.

There are actually earlier stories that also talk

about a man, and a boat, and a great flood.

Lara uses her expertise

to decode an ancient clay tablet found in Mesopotamia.

The language is written in cuneiform,

the world's earliest known form of writing.

It dates to the 7th century BCE,

a few hundred years before the Old Testament

is believed to have been written.

This tablet is a portion of the "Epic of Gilgamesh."

It is a story about a king who is from Uruk,

who goes on a great journey to try and find immortality.

The legendary Sumerian, King Gilgamesh,

is believed to have ruled the city of Uruk in around 2,700 BCE.

In the epic,

Gilgamesh meets an immortal man called Utnapishtim,

who tells him of a great flood which occurred in his youth.

It's a surprisingly similar story to the Bible.

"All the windstorms and gales rose together.

And the flood swept over."

In this version of the flood story,

the gods also decide the whole human race must be wiped from the earth.

Utnapishtim is the chosen man who has a similar visitation from a god,

warning him of the flood and telling him to build a boat.

A fierce storm rages.

The air is thick with rain,

and the south wind drives violent waves across the land.

Finally, the storm abates.

The boat runs aground on a mountain top and humanity is reborn.

The name of the central character is different,

and the flood lasts for six days instead of 40,

but this tale has much in common with the Bible story.

The tablet which details the flood in the "Epic of Gilgamesh"

is thought to derive from a version of the story

at least a thousand years earlier.

And it's not the only Mesopotamian text of this time

to detail a cataclysmic flood.

There's actually a corpus of many different myths

talking about a great flood.

At least two other known stories exist

from the early second millennium BCE.

This suggests that flooding was a big preoccupation

for early Mesopotamians.

Our biggest question is, therefore, are they all

describing the same flood event?

In Oman,

1,000 miles to the southeast of Uruk,

is the village of Qantab.

Here, maritime archaeologist Alessandro Ghidoni

runs a unique specialist research boatyard.

He uses tools and techniques from thousands of years ago

to investigate how ancient civilizations built their vessels.

Experimental archeology

brings you closer to the people of the past.

It forces you just to put yourself in the mind of people

and try to solve problems that they actually have faced.

Alessandro wants to understand

how the ancient Sumerians built their boats

and whether they could've built one

to survive a flood of Biblical proportions.

He investigates an amazing find,

a cuneiform tablet dating to around 1,700 BCE.

This tablet is an incredible discovery.

It's a list of steps

to build

the Ark.

This text is an ancient construction manual,

the first of its kind ever found.

And what's more, it's for a gigantic boat an acre in size.

It seems to be a blueprint for the Sumerian ark

described in stories like the "Epic of Gilgamesh."

It gives you, first of all, information about

the materials used, the techniques.

It's an incredibly valuable archaeological find.

The tablet describes how the ark

had a hull made of twisted fiber ropes attached to a wooden frame.

Alessandro wants to put this ancient design to the test

to find out if it's a seaworthy craft, or a purely mythical invention.

The ark outlined on the tablet is enormous,

so he plans to make a sample section of it 1,800 times smaller.

This will help him study

the materials and techniques described.

Every material has a limit.

I immediately wonder is it possible to build something

to escape the flood, to survive the flood.

Alessandro and his colleague Ayaz Al-Zadjali

set out to gather wild reeds,

a likely candidate for the twisted fiber ropes,

to put this 3,700-year-old blueprint to the test.

At Uruk, in Southern Iraq...

Jaafar is trying to find out what archaeological evidence there is

for the Sumerian and Biblical flood stories.

In the 1920s and '30s,

archaeologists excavated many ancient Sumerian cities.

At several of the sites, including Uruk, they found a thick layer of red clay.

This distinctive clay is ancient mud caused by river flooding.

They took lots of photos

and whenever excavation teams in Southern Iraq

found a thick bed of red clay

they think it is the Great Flood.

This supposed proof of the Biblical flood

made headlines around the world.

But Jaafar believes there's more to the story.

He turns to evidence from a nearby quarry,

where thousands of years worth of sediment layers

are on show.

In this quarry, we can see a succession of different sediments

different in color, of course, and in thickness.

Each color represents a different sedimentary environment.

So here, for example, we have the red clay

which is the flood.

This distinctive red clay layer

is evidence that the Euphrates flooded this area

almost 7,000 years ago.

But the quarry also shows something else intriguing.

We don't have one flood, one major flood in Southern Mesopotamia.

What we do have in Southern Mesopotamia

are multi-layers of floods. And we can see them clearly.

This discovery is turning the 1930's theory on its head.

The origins of the Biblical and Sumerian flood stories

could lie not in a single catastrophic flood,

but in many.

Jaafar wants to find out how bad these floods were

and how ancient people coped with them.

But here at Uruk, remains left by later civilizations

make exact dating challenging,

and the continuous movement of the river Euphrates

has covered the land in sediment,

so evidence on the ground is hard to untangle.

He heads over two hours' drive south

to an even more remote site that has remained unoccupied

for over 2,500 years.

Ancient writing expert

Lara Bampfield examines cuneiform texts for any more records of great floods.

She wants to find out if the "Epic of Gilgamesh" flood story

was based on a real event.

She investigates one of Mesopotamia's most famous ancient artifacts.

This is a replica of a clay prism that was made in around 1,800 BCE.

Each of the prism's four sides

is covered with tiny cuneiform writing.

This prism is really important.

It tells us a succession of kings

that ruled Southern Mesopotamia and also the cities.

Rather than recording a story,

this text was written as a historical account.

While some of the reigns are unfeasibly long,

many of the kings it mentions can be verified

from other archaeological sources.

Lara spots a familiar name.

Up here, we can see Uruk,

but further down, we can see one of the kings of Uruk, Gilgamesh.

This is an exciting piece to the puzzle.

It suggests that the legendary king was a real person.

Could the Great Flood, which appears

in the "Epic of Gilgamesh," have happened too?

Lara searches the cuneiform for any mention of a flood event.

"Ejer a-ma-ru ba-ur3-ra-ta.

Kish-ki nam-lugal-la."

And that means, "After the flood had swept over the land,

Kish became the seat of kingship."

This is an incredible piece of evidence.

The Sumerian king's list

records the Great Flood as historical fact.

This echoes the Bible's claim that it took place

before the foundation of cities like Uruk.

The people who created this document in 1,800 BCE

describe a great flood in their ancient past,

a civilization-defining event.

How did this catastrophe unfold?

Back in Qantab on the coast of Oman...

Alessandro and Ayaz

have found a good supply of reeds for their test ark.

But working in this area is not for the faint-hearted.

There's many animals here?

Yes.

Really? Snakes?

Snakes, yes.

Scorpions?

Yes. Scorpions.

Oh.

Thin reeds like this

may not seem like the obvious choice for boat-building,

but they have some unique structural properties.

The good thing about reeds is first of all the flexibility

and the strength of this material.

While it's easy to bend, it's quite difficult to break,

which is a good thing when you want to build a boat.

You want to use something that is resistant

which is strong enough sailing in rough sea.

The team takes the reeds

back to the boatyard

to begin construction of their sample section

of the Sumerian vessel.

The ancient instruction manual that they are following

describes how the ark builders made the reeds into rope-like bundles,

twisted and lashed together with date palm fiber.

Alessandro wants to test

if such bundles could create an effective waterproof hull.

He uses archaeological evidence of ancient Mesopotamian reed boats,

together with his knowledge of modern versions,

to prepare the reeds.

We have evidence for the use of these ropes

in the Bronze Age and also in the Neolithic.

They are handmade

and it's a long process to make them.

So, we're talking about a lot of work,

and probably the involvement of a big community.

The pair's next task

is to attach these bundles to a wooden frame,

like the Ark tablet describes.

They have constructed a section of the hull

from locally-grown cedar wood,

also available in the ancient Middle East.

Alessandro and Ayaz bind the bundles tightly to each other

and to the frame to prevent water seeping through the gaps.

But as they work, Alessandro spots a problem.

Basically, what we notice is that

there's these interstitial spaces between the bundles.

Some of them you can fit one finger.

So, you want to avoid that because it's a hole

in the hull of a boat.

It's likely the ancient boat-builders

faced this same problem.

Alessandro and Ayaz draw on their own experience

to figure out how the Sumerians might've plugged the holes.

We came up with this solution by putting some crushed reeds

in these gaps between the bundles

to close these holes and at the same time to create an even surface.

Within just a few hours, the sample structure starts to take shape.

This speed of assembly would've been an advantage

for an ark builder working under the pressure

of an impending flood.

I feel quite good about this experiment.

People don't really think reeds are a strong material,

but actually when it's lashed together

and also lashed onto frames,

it becomes a very solid, very strong layer.

You can walk on it if you want.

The experiment reveals that reeds can form a hull

that's both strong and hole-free.

But could an ancient ark built this way survive for 40 days and 40 nights

on the ocean waves?

Jaafar arrives at the remote ancient Sumerian city of Eridu.

It lies 40 miles south of Uruk and appears in another version

of the Sumerian flood story, the Eridu Genesis.

One of the oldest-known cities in Mesopotamia...

Eridu has been unoccupied since the 5th century BCE.

At its heart, lies a mound made of bricks, another ziggurat.

Jaafar wants to explore this untouched landscape

to find out how the ancient floods unfolded

thousands of years ago.

First, he scours the desert for traces of ancient water.

Once I dig a small bit, I can see the sand here.

We can find some fossils.

This was actually a river or a riverbed.

Jaafar launches the drone to get a clearer view of the river.

Immediately, hidden features in this ancient landscape

become visible to his expert eye.

We can see the ancient Euphrates so clearly here.

You can see meandering lines.

And close by, Jaafar spots another clue,

this time, straight lines.

They can only be man-made.

You can see some irrigation canals.

We call it a herringbone irrigation system.

These canals are known as herringbone

for their branching shape.

The Sumerians pioneered this clever channel system

to divert water to farmers' fields when the river was high.

Jaafar and his team have been documenting Eridu's canals for the past five years.

They use satellite imagery

to identify potential man-made waterways,

and check this against evidence on the ground.

Now, they can finally combine their thousands

of GPS coordinates and ground measurements

to build a picture of Eridu's canal network.

The result is breathtaking.

It reveals a maze of ancient canals

connecting Eridu's farmland with the river Euphrates.

It covers almost 80 square miles.

In total in the Eridu region

we have more than 200 large, main canals.

And then we have 4,000 small or branching canals.

Some of these canals date from the fifth millennium BCE,

making this the oldest-known preserved irrigation network in the world.

It is evidence that people here

harnessed the power of the Euphrates river much earlier than previously believed

to develop some of the world's first agriculture.

Next, Jaafar surveys the landscape for evidence of flooding.

He spots distinctive markings near the riverbed.

In this section here, it is so clear.

We have a crevasse splay.

Crevasse splays occur when river water

breaks through weak points in the riverbank.

In other parts of the world, rivers flow through valleys,

but in Southern Mesopotamia, they move across the top of the flat land,

bound by small banks of sediment.

The number and size of the splays here

suggests water often burst through the riverbanks,

spreading for miles across the floodplain.

To a Sumerian, this may have looked like a massive ocean.

Flooding is the most disastrous thing here.

We don't have earthquakes,

but we have, unfortunately, flooding.

Jaafar thinks that the origins of the flood stories

could stem from the devastation

caused to farmers' fields when the riverbanks broke,

often in the spring when the river swelled.

Flooding actually is a continuous tragedy for them.

People spend the year taking care of their farm

and then, suddenly, we have flooding that destroys their farm.

These devastating, if relatively localized, floods

are one explanation for the origins of the flood myth.

But why do both the Bible and Sumerian tablets

tell of a single great deluge?

Was one flood greater than all the others?

At University College London,

Mark Altaweel, a colleague of Jaafar's,

prepares to analyze some important sediment samples.

We got some samples from Uruk.

Well, it's really good stuff.

- Wow. This is the best. - Fried earth.

Yeah, fried earth.

Mark's team took these core samples

from just outside Uruk.

They come from layers deep in the ground, corresponding to around 4,000 BCE,

just before the city was founded.

The Biblical and Sumerian stories

both say the flood occurred before Uruk became a city.

Mark and his colleague Anke Marsh

hope the samples might reveal

if this was a period of continuous flooding

or a series of smaller isolated events.

The question is, of course,

is, is Southern Mesopotamia a kind of environment

where a flood story could develop?

A place where, where you can see extensive flooding,

you can see why people would have to flee, perhaps, away from this kind of place.

They want to isolate tiny plant fossils called phytoliths,

which could allow them to reconstruct

what type of plants existed around Uruk in 4,000 BCE.

Phytolith translates as "plant rock."

And it is actually that.

It is silica that has been taken up from the soils by the plants.

It's hardened within their cells.

And when the plant dies, the plant rocks are deposited into the sediment

and then preserved over time.

Anke uses a centrifuge

to spin the samples at 800 revolutions per minute.

This separates out the phytoliths from the rest of the sediment.

She then records the proportions

of each type of plant cell visible in the sample.

Mark, do you wanna come here? I'll show you something.

What do you got?

This is a really interesting slide.

There are a lot of sponge spicules.

These are parts of sponges that live in ponds or lakes.

And if you look here, we have a diatom.

Oh, right.

This diatom is a micro-algae, which lives in marshes.

Looks quite convincing.

We're in this freshwater environment in the early phases of Uruk basically.

Yeah. Pretty excited about this one.

Yeah, definitely. It's good results.

The sample shows that around 4,000 BCE,

just before Uruk's foundation,

people weren't only dealing with occasional floods.

They were surrounded by marshy wetland,

proof that the whole environment was much wetter than today.

There's a lot more standing water in this area,

which is something that you wouldn't really associate with

when you think about Iraq.

Mark and Anke want to know how this wet period

affected the founders of the first cities

and their descendants who would go on to compose the flood stories.

In Oman,

Alessandro and Ayaz prepare to put ancient Sumerian

waterproofing techniques to the test.

The instructions on the clay tablet

describe a natural sealant, known as bitumen.

Bitumen is basically like

a petroleum product that you can

find naturally in some areas of the Middle East.

Mesopotamia is one of the world's

richest regions for oil and bitumen.

The ancient Sumerians realized its potential

and used it as a water-repellent layer for buildings and roads.

This is the kind of bitumen that was used in Mesopotamia

during that time.

Rock hard bitumen.

The ancient Sumerians

would've collected bitumen from seeps on the surface

and melted these lumps down over a fire to a pliable liquid.

You have to be careful when you do this process

because you heat the bitumen and you reach

temperatures over 100 degrees.

It then becomes quite dangerous

because if you spill it on your skin

it sticks on your skin and it burns.

It's dangerous.

You have to be very careful.

All right, so it's time to add the fish oil.

Alessandro has studied

the chemical composition of ancient bitumen

and knows that other ingredients were often

added to improve its natural properties.

Fish oil to make the bitumen flexible when dry,

sand for strength,

and plant material to bind it all together.

We know that they used crushed reeds

in a process that just reminds me a bit of fiberglass,

like prehistoric fiberglass.

I think it's good. I think it's ready.

Once the bitumen has cooled, the team can apply the black liquid

to the outer surface of the boat.

This is a wooden roller that helps the application

of the bitumen on the hull.

It was used until very recently in Southern Iraq for the same purpose.

It's a very simple, but very effective tool.

They add a final coat of sand

to protect the bitumen from the sun.

Yes, that's nice.

After working for hours in the searing heat,

they finally test the sample

to see if it's waterproof.

Yes, it's perfect.

The bitumen has held true and waterproofed the reeds.

Good job.

Could this technology have been

scaled up to waterproof a huge ark described

in the 3,700-year-old text?

Alessandro follows the instructions laid out

on the clay tablet

to sketch out a design for the Sumerian ark.

One line of cuneiform reveals something surprising.

It reads,

"Draw out the boat that you will make on a circular plan."

This is no traditional boat design.

The Sumerian ark is round.

It doesn't look like the ark in the popular imagination at all.

It looks like a kind of boat which was very common in Iraq

until relatively recently.

It's a coracle and it's called Kufa in Arabic.

It's basically a basket coated with bitumen

and used to carry people and goods and animals

across the river.

All these cuneiform clues

finally reveal the full design of this mighty ship.

The Sumerian ark described in the tablet is monstrous.

A vast round vessel...

with a massive wooden skeleton...

bound tightly with reed bundles...

and sealed with hot bitumen.

Alessandro's tests show it would be tough and watertight.

With walls two stories high,

and a deck half the size of a soccer field,

this ark was designed not to sail, but to survive.

Floating like a gigantic basket in the floodwaters,

it was intended to preserve life within its buoyant walls.

It's spacious, it's large.

You can carry a lot of people.

It's incredible.

An ark of such epic proportions would take hundreds of people to build,

a monumental undertaking for the ancient Sumerians.

What evidence is there that the boat described

on the Ark tablet was ever actually built?

Mark is on a mission to discover the impact

of the wet and marshy climate on the early people of Uruk.

Their experience could help to explain the origin

of the Biblical and Sumerian flood stories.

He turns to an unusual source of information,

stalagmites from a cave in Northern Iraq.

Stalagmites are basically

rocks that grow from cave drips.

So, imagine a cave is dripping water, uh,

and it grows this rock over time.

And it sort of forms these nice, kind of, conical shapes,

which we can then sample to study the paleoclimate,

specifically ancient rainfall.

He can use these rare time capsules

to build a detailed picture of the ancient climate in Northern Iraq,

nearer the source of the Euphrates river.

This is a stalagmite that we had sampled.

It's about three meters in height.

So, it had grown for about 10,000 years.

And it also has annual layers, like a tree ring.

Mark studies the chemical composition

of each annual layer.

He looks for those with the highest magnesium levels,

a marker of high rainfall.

You see this nice spike?

This is, literally, the wettest century in Iraq's history

for the last 10,000 years.

And it exactly occurs around 3,500 BC.

3,500 BCE is around the time when Uruk becomes a city.

Mark believes this is more than a coincidence

that Uruk is founded during the rainfall deluge.

The two events are closely linked, and mark a turning point in human history.

The immense rainfall in Northern Iraq swelled the Euphrates river

and turned areas of Southern Mesopotamia into lush and fertile wetlands.

Settlements like Uruk now had a surplus of agricultural goods,

which allowed them to trade.

The Sumerians exported these products to remote lands in one of the world's

first large-scale trading networks,

and they imported stone, metal, and wood.

This allowed them to grow their cities.

The need to administer the goods coming into the city

opened up new job opportunities for people and writing flourished.

Rather than forcing them to flee,

this influx of water gave the Sumerians a reason

to stay exactly where they were and prosper.

But the Bible refers to the flood

as a catastrophe from which humanity recovered,

so what was this traumatic event?

In Oman, Alessandro wants to know

if the giant Sumerian vessel described on the Ark tablet

was ever actually built.

He knows from past experiments that bitumen can behave differently

when it's submerged in water.

It will harden because the water cools it down.

It will become brittle and it could crack because of

the difference between the flexibility of

the hull made of reeds

and the bitumen which is much harder.

This might not matter to a small river craft,

which could easily come to shore for repair,

but a colossal ark with greater pressures across the hull,

floating far from land, would be in huge trouble.

The water will apply extraordinary force

pushing the bitumen into any

even small hole or gap

causing leakage.

In a 40-day flood, this version of the ark would surely sink.

If the massive ark described on the tablet is not viable,

why do these detailed instructions exist?

The size is definitely very exaggerated.

But everything else makes sense,

materials make sense, processes make sense,

and proportions also make sense.

This leads Alessandro to one conclusion.

I think it could have been a mathematical exercise

to educate students on maths and proportions.

And, perhaps, using something like the flood myth

just to kind of spark their interest.

The fact that ancient math students

may have been using the Sumerian Ark for their studies

suggests this story captivated people then

just as much as today.

What were the roots of this legend?

In London, Mark delves deeper into the Iraqi stalagmite data.

He's interested in the climate when the Sumerian flood stories

were first written down in the third millennium BCE.

What we're seeing here is this

big spike around 3,500 BC.

Also, we see a kind of... a somewhat sharp decline,

actually, later around 3,200 into 3,000, uh, BC,

which is probably telling us it's getting drier.

This is an exciting discovery.

It shows that the wet period in which civilization

began to flourish was short-lived.

Mark wants to know how these urban-dwellers

met the challenge of a drying world.

To find out, he turns from the ground samples

to the air, to decipher satellite imagery,

another valuable source of information

on Iraq's past environment.

CORONA satellite systems

were basically spy satellites from the 1960s and '70s

that were used by the United States

to look at regions related to the Cold War.

This satellite imagery is a unique resource.

It shows Iraq when it was much less developed

than it is today.

And studying it reveals ancient secrets lying just beneath the sand.

You can actually make out nicely

these canals.

So, you have the city of Uruk here,

the ancient site, uh, and then these canals

that would've gone into and out of the town itself.

By dating structures found alongside the canals,

Mark has discovered that there was an intensification

of canal-building after 3,000 BCE,

when the climate had become drier.

Ancient texts record that many of the region's major canals

were funded by the Sumerian kings.

Think of it as people who have vested interest in power.

If you're interested in maintaining that power, what do you do?

Well, you have to invest again into your cities.

You have to develop ways in which you can sustain those cities

and-and irrigation water channels are gonna be critical to this.

The kings built large canals that drew water from the Euphrates

to irrigate the city's now dry gardens and fields.

They developed more and more complex ways to manage the precious water.

Dams waterproofed with bitumen

regulated the flow from rivers into canals...

while systems of weirs, distributors, and reservoirs

controlled and captured water, sending it to where it was most needed.

While the land around them dried up,

the kings kept the cities going and growing.

Their awe-inspiring ability to control nature

and provide food for their people gave the kings power and status.

Mark believes that the catastrophe which prompted the first flood stories

could actually have been this drier time.

This is a time of great change.

It's not just the environment that was changing,

but also, people were changing.

The burgeoning Sumerian cities had to learn to cope

with two opposite extremes in climate.

Occasional floods were still an issue, but now, there were also regular droughts.

This fragility was ingrained in the minds of the Mesopotamians

because they saw the nature being quite fragile

and quite volatile.

And life, in a way, was, was like that as well.

They... Their fortunes can change overnight.

The Sumerian flood stories could perhaps have been a metaphor

for the vulnerability of early civilization.

Why has this particular myth survived over thousands of years,

retold from the Bible by hundreds of generations

across the world?

Lara thinks the key could lie in how cuneiform writing itself developed.

This is a very old tablet,

dated about 3,000 BCE.

Each image or sign represents an object.

So, we can see very clearly a representation of barley.

And that is exactly what it means, barley.

Over just a few centuries,

the characters in this early cuneiform script changed.

They move from just showing a particular object

to try and express more of a sound or a syllable.

This was a huge transformation.

Now, symbols could be put together to make longer words

to express more abstract, complex thoughts.

A change Lara believes was driven by the Sumerians'

growing interest in their own origins.

They were almost obsessed with trying to find out

what came before them and how they came to being.

This sophisticated cuneiform writing,

the Sumerians' greatest invention, spread across Mesopotamia

in the centuries that followed.

Each civilization embellished the flood story

and made it their own.

And when Jewish writers compiled

the Bible's Old Testament in the first millennium BCE,

after years of living in this region,

they included the flood story as they sought to understand

their own place in the universe.

The teams' new discoveries of repeated inundations,

and dramatic climate changes shed new light on the real events

that inspired the flood stories.

The Mesopotamians' volatile relationship with the river Euphrates

is a story so powerful it endures with us to this day

as the story of Noah, the Ark, and the Great Flood.