Original subtitles

This is a land known by two names.

The first is Persia.

TRADITIONAL MIDDLE EASTERN SINGING

Ancient.

Mysterious.

A place of adventure...

..of mighty temples and palaces...

..built by powerful kings.

A land of unimaginable beauty.

The other is Iran.

Isolated...

..proud...

..defiant...

..especially of foreign interference.

Western documentary teams are seldom given access,

but I am a British journalist

and I've been granted a rare opportunity to travel

across this vast country

and discover its complex history and culture for myself.

The Persians can seem like a mystery at the edge

of the western imagination,

in the Old Testament, or battling Alexander and the Romans

in classical history.

But the ripples of Persia's art and language have travelled

outwards throughout the world,

transforming culture across Europe and Asia.

If you think you know the Persians, think again.

In this first episode,

I'm going to start at the birthplace of Persian civilisation,

at one of the world's first cities,

and discover the mysterious writing of its people.

Persia's great kings built a vast empire and a rich culture

that became the envy of the ancient world.

I'll find out how they defeated no less than three Roman emperors

and how the Arab armies eventually conquered the Persians

to build a new Islamic empire.

So, come with me on a magical journey

to reveal Iran's fascinating ancient past

and its impact on the world.

To most people, Iran is a closed book

and our understanding of it has been largely driven

by the last 40 years, when, in 1979,

revolution came to Iran and Ayatollah Khomeini

transformed it into an Islamic republic.

The country has been locked in conflict with the West ever since.

When you look at modern Iran,

when you see it surrounded by hostile forces,

by countries that are hostile to it,

Iran would like to remind them that there was a time

that we were, not only were we up there at the top table,

we were the hosts of the top table.

And look at this.

And look how much it has actually influenced your literature,

your art, if you like.

The Persian civilisation and the art and culture it produced

was once the envy of the ancient world.

But, over the centuries, Persia was invaded again and again

by brutal conquerors, greedy for her lands and treasures.

They brought with them new laws, new languages and a new religion.

But Persian culture survived, even thrived.

Today, Iranians' sense of who they are

is as strong as it was when their story began.

They are the only people in the Middle East

to preserve their identity and language

despite waves of invasion and revolution.

If you look at the people of North Africa,

they used to speak Latin, now they speak Arabic.

If you look at the Syrians, they used to speak Greek,

now they speak Arabic.

So do the Egyptians.

It's the Persians who have kept their language,

and, by the way, only the Persians.

There's something special going on there.

That special thing that allowed Persian language and culture

to survive was, remarkably, this book.

It's called the Shahnameh...

..a collection of tales about Iran's pre-Islamic kings.

The characters are part-mythical and part-historical

and the book tells of their heroic deeds

against divine and human forces.

It's a poetic rendition of these supernatural tales,

historical tales, romances.

It's really a most magnificent, grown-up storybook.

Shahnameh is the soul of Iran.

It's the absolute essence of being Iranian.

It's a masterpiece of Persian

literature and history and language.

And, to most Iranians, certainly to me,

it's like a Bible.

Although it was written in the 10th century,

the characters and tales are still much-loved today

because they provide a link between the present

and 3,000 years of Persian culture.

I'm starting my journey here in Tehran

because I want to get a taste of this magical storybook.

I'm in a south Tehran teahouse where a 1,000-year-old story book

is about to come alive on stage.

The Shahnameh, the Persian Book of Kings,

is part-myth, part-epic history

and Iranians can't get enough of its adventures.

It's central to their sense of identity.

If you want to understand the story of the Persians,

you need to dive into the Shahnameh.

The performance is about to begin.

HE SPEAKS IN FARSI

Tales from the Shahnameh are retold by storytellers

in theatres and teahouses all over Iran.

And the man who wrote it would have been astonished

to learn his life's work would still be performed and read

1,000 years later.

He was called Abul-Qasem Ferdowsi.

Handed down from one generation to the next,

his epic book became Iran's national myth.

Ferdowsi took 30 years to write the Shahnameh,

but its storytelling power has lasted 1,000

and travelled far beyond the borders of Persia.

I'm of North Indian heritage with a Persian name, Samira,

and was raised speaking Urdu, a language closely related to Farsi.

And in the Indian comics I read as a child,

there were all these stories about the Persians as conquerors,

as bringers of culture, as religious refugees.

I want to find out how Ferdowsi's stories protected Persian language

and culture from repeated attempts to destroy them.

But, first, I'm going to explore the fabled civilisations

that emerged in this region...

..and find out how the Persian Empire was born.

Our story starts over 3,000 years ago...

..with some ancient plumbing.

This is the end of a qanat,

an underwater tunnel that was dug to bring water down

by the force of gravity from the mountains

right here to where people needed it to drink and irrigate their fields.

And it's still icy cold when you touch it.

Qanats made life possible.

They made barren landscapes fertile.

They allowed people to put down roots...

..to start making art...

..crafting beautiful objects, such as this ornamental axe head...

..adorned with the tiny figures of two wrestlers.

Or this figurine of a mysterious, stocky warrior dressed in snakeskin.

Archaeologists have nicknamed him Scarface.

But the skills of these early people

went far beyond the ability to fashion bronze and gold.

They also made extraordinary monuments...

..like this.

I've come to explore the ziggurat of Chogha Zanbil

in Iran's southwestern desert.

The people who built it were called the Elamites

and they attached great spiritual importance to mountains.

Where there were no mountains, they built their own.

This was constructed over 3,000 years ago.

This place is such a beautiful mystery, a relic of a lost world.

And I'm trying to imagine it as it was,

bustling with temples to the many Elamite gods and goddesses,

and the brickwork burnished with gold and silver,

a statement of power by its king.

Time, wind and sun have since taken their toll,

but the temple was once full of beautiful objects and statues

devoted to the Elamite gods.

The bull was central to Elamite culture.

In early Iranian creation myths, it was the first animal in the world.

The Elamites worshipped a bull god called Inshushinak.

And their kings constructed ziggurats like this to worship him.

In its shadow,

archaeologists found this blue, quartz pendant

polished and etched with two Elamite figures.

This is a really remarkable and absolute unique piece

of stone working because it depicts an image of the king

and then his daughter, and we rarely see women coming to the fore,

of course, in Elamite sources, unfortunately.

So, here we have one. And she's named as well as Bar-Uli.

And there she is, standing diminutively.

She's depicted on a much smaller scale in front of her father.

But the fact that she's there at all, her presence is really quite

remarkable in an age, really, where women just get bypassed

in the royal record.

We know of very, very few Elamite queens or princesses.

Archaeologists made other finds, too,

taking us even closer to the people who once worshipped here.

This footprint is over 3,000 years old.

It's tempting to believe it belongs to Bar-Uli,

the daughter of King Shilhak-Inshushinak,

who gave her the pendant.

Perhaps she came here with her father to worship,

to watch the bloody sacrifices carried out by priests

to gratify the Elamite gods.

But Chogha Zanbil is much more than a temple.

It's a book designed to be read by future generations.

This is the writing of the Elamites called cuneiform.

There are thousands of engraved bricks.

Only nobody knew what the writing meant until the 19th century

when archaeologists unlocked their secrets.

The Chogha Zanbil inscriptions are very repetitive

in many respects,

but they're important because what they do is quite

literally stamp the authority of the king on to the building itself.

So, every brick essentially is saying,

"I am the King of Elam, the King of Kings".

The Ziggurat of Chogha Zanbil is testimony to the sophistication

of the Elamite civilisation,

a civilisation that was not only literate,

but gave rise to one of the world's first urban cultures.

I'm now travelling a few miles north of Chogha Zanbil

to explore what remains of the Elamite capital city...

..Susa.

If you want to understand the complexities of Persian culture,

then you couldn't come to a better place than Susa.

I am really aware of the hum of the modern city of Shush

in the background. And the ruins of this Elamite city

are known to archaeologists as the 15th City

because they're the earliest of

15 distinctive sets of eras and ruins on this site,

dating back to at least 1,500 BC.

Excavations first started here during the 19th century.

Among the finds, this bronze of two Elamite worshippers.

In her left hand, the woman clutches a bird,

whose significance is unknown to us.

It's incredible how rich the land around here is

with these pieces of Elamite culture.

So, just lying on the ground, we've spotted stuff and picked them up

like this piece of blue, glazed pottery

which has this amazing colour.

And then this, you can see the grooves in it.

And we've been told by the guide it's the lid of a storage jar

that would have contained something like rice.

Stories about the wealth of Susa spread throughout the ancient world

and soon her enemies began to circle.

To the north, the Medians,

and to the east, the war-mongering Persians led by King Cyrus.

This glazed relief shows a Persian warrior ready for battle.

It was during the 7th century BC that King Cyrus led

his mighty army to first overthrow the Medians,

and then the Elamites, after he captured their capital.

With the defeats of both kingdoms, Cyrus became Cyrus the Great

and his descendants built a new capital here at Susa.

The Elamites were now subjects of a new empire,

the Persian Empire.

The centuries have been unkind to what Cyrus

and his successors built here.

Susa eventually disappeared into the sands of time

until it re-emerged after archaeologists

started digging here in 1850.

What they discovered here was vast.

I want to give you an idea of exactly how vast

those buildings were.

I know what you're thinking.

This building looks remarkably well preserved.

Is it a fortress?

Is it a palace?

This is the Chateau de Suse.

The chateau was built in the 1890s

on the orders of a French archaeologist,

Jean-Marie Jacques de Morgan.

Morgan needed somewhere secure for his excavation team

and their finds while they worked on the Susa site.

He thought what could be safer than a French castle?

And he decided to use the ancient bricks from all around here

at Susa and from the ziggurat at Chogha Zanbil

to build this place

from 15 different buildings up to 3,000 years old.

And, once you know, you start seeing it everywhere, like this one.

These are bits of glazed ceramic probably from a temple or a palace.

It's not just glazed bricks.

If you look carefully, many bear the language of cuneiform.

From the Elamite capital of Susa,

to the city built by Cyrus to replace it,

right through to the early Islamic period,

this single building contains the span of Persian ancient history.

The bricks have all ended up in this pastiche

of a French medieval fortress,

a fitting symbol of how colonial-era archaeologists

saw themselves as superior protectors of civilisation,

while desecrating ancient sites like Susa.

So, if you can, put the archaeological vandalism aside

for a moment, imagine the palaces and temples

once constructed from this enormous quantity of bricks.

It would have looked truly monumental.

Susa was once one of the Persian Empire's greatest capital cities.

After Susa,

Cyrus the Great conquered the city of Babylon in 539 BC.

And we know this because of what archaeologists found there,

the world's earliest example of political spin.

This is known as the Cyrus Cylinder and it's an exact copy,

but the original is kept in the British Museum.

And, here, inscribed in all these tiny lines of cuneiform,

is a piece of propaganda,

a kind of compact trophy, which describes how Cyrus

overcame his enemies, not through violence, but through showing

tolerance towards the people and their gods.

"My vast army marched into Babylon in peace.

"I did not permit anyone to frighten the people

"and sought the welfare of Babylon...

"..and all its sacred places".

So, this is very clearly some Persian spin.

It was a conquest,

but presented very much as a liberation of peoples.

And it's come to affect how, for generations,

we've regarded Cyrus the Great.

We absolutely bought in to his propaganda campaign.

The Cyrus Cylinder is one of the world's earliest examples

of propaganda, but Cyrus' policy of tolerance did have an impact

on different religious populations -

one in particular, the Jews.

The Jews who were brought to Babylon by the previous Babylonian king

were allowed to go back to their homeland.

So, Cyrus enjoys a particularly important position,

both for us Iranians as well as for Christians

and also the Jewish people.

Susa is one of the world's oldest cities.

People have lived here for over 6,000 years.

And it was not only home to Persia's great kings,

but to one of the Bible's greatest heroes.

Not far from the chateau can be found this unusual structure.

It is or is believed to be the tomb of Daniel,

famous for his stay in the lion's den in the Old Testament.

Jews and Muslims honour Daniel as a virtuous man,

who maintained his religious beliefs throughout

the long years of exile in Babylon,

living to see the liberation that Cyrus promised on his cylinder.

As a child, one of my favourite stories in the Bible

was that of Daniel in the lion's den.

And here in Susa is where he died.

And this is his tomb.

And it's incredible to find that out.

This place has become a site of pilgrimage for Muslims,

for Christians, and for Jews.

And, after they were freed by Cyrus, many Jews chose to remain

and are still here today.

It may come as a surprise to learn that the largest community of Jews

in the Middle East outside of Israel is here in Iran.

So, what happened to Cyprus and this first Persian Empire?

To find out, I'm going to travel many miles east

into the deserts of central Iran to Pasargaede.

Pasargaede was where Cyrus made his capital.

Now all that survives is his tomb, remarkably modest for the founder

of what was the biggest empire the world had ever seen.

The Persian Empire, at its height, stretched from

Greece to the Indus,

from the Occis through to what we would now know as Libya.

I mean, this is vast in the ancient world.

Iranian visitors flock here, particularly during the holidays,

to see the tomb of the king, who not only founded the Persian Empire,

but its people's sense of national identity.

The tomb of Cyrus lay at the centre of a huge, formal, walled garden

known in Persian as a pardis, from which we get the word paradise.

And, although it's hard to imagine right now,

this was once surrounded by lush greenery and flowing waters -

a statement of Cyrus' civilising power

against the wild desert beyond.

A clue to what Cyrus' great garden once looked like can be found

in the familiar design of Persian carpets today.

Many are based on his garden's layout.

Imagine Cyrus' tomb in the centre,

surrounded by statues of fantastic birds and beasts.

Qanats supplied water for the ponds, flowers and trees,

which provided shade on hot, summer days.

His gardens have long since perished.

But Cyrus did attempt to secure his family's legacy.

He carved a simple inscription

in three different forms of cuneiform...

..Elamite, Babylonian, and a brand-new script

named after this new Persian dynasty...

..the Achaemenids.

The words are very simple.

"I, Cyrus the King, an Achaemenid."

This was a declaration that Cyrus the Great's vast new empire

was under the rule of the Achaemenids...

..a Persian royal dynasty.

Cyrus the Great may have forged the first Persian Empire,

but, in 515 BC, it was his successor, Darius I,

who built the jewel in its crown...

..the legendary city of Persepolis.

Darius was the greatest royal architect of his dynasty.

Even in its ruined state,

the imposing gateways,

monumental columns, and exquisite reliefs

leave you in no doubt about the message Darius wanted to project.

His empire heralded a new world order.

Darius was also famous for many firsts.

He dug the first Suez Canal,

introduced standardised weights and measures,

and coinage, too.

It was this administrative genius

that earned him the title Darius the Great.

Archaeologists have found tablets here at Persepolis,

showing careful record keeping and rates of exchange

for payments in kind.

To his subjects who admired this administrative flair,

their Emperor was known as Darius the Shopkeeper.

Darius didn't bother to fortify Persepolis.

He didn't need to.

All his enemies had been defeated.

And here are the enemies his dynasty had overcome,

all subject to the Persian King.

A real highlight of Persepolis is this magnificent frieze

which shows 23 subject peoples of the Persian Empire

queuing up to bring their tributes to the King.

In incredible detail on their faces and costumes,

you can see they come from everywhere,

from southeastern Europe, to down here,

these five are from Sind in India, modern Pakistan,

bringing gold dust and spices and battle-axes.

And over there, there are figures from Nubia,

bringing elephant tusks and a giraffe.

Persepolis was a masterpiece of imperial architecture.

And you might assume Darius exploited a vast army of slaves

to build it.

But archaeologists made a surprising discovery.

There were lots of people working at Persepolis.

We also have tablets from Persepolis which reveal a lot of interesting

information about the workmen -

the salaries, how they were paid in kind.

And also women worked at Persepolis.

We know that, for example, women were overseeing some particular

parts of the structure.

And, in one case, one woman gives birth to twins and she receives

a special allowance for maternity.

And, so, it's all very interesting

how he produced this enormous palace.

The imposing entrance to Persepolis is where King Xerxes,

Darius' successor,

inscribed a message that left every visitor in no doubt

about the power and ambition of his empire.

It reads, "I am Xerxes the Great King,

"King of Kings,

"King of the lands of many people,

"King of this great Earth, far and wide."

Xerxes I called this his Gateway Of All Nations.

And, for anyone arriving at Persepolis, there is a real sense

of the whole world passing through here,

from the clearly Assyrian figures guarding each side of the gateway,

to the classical columns that you could recognise,

to the graffiti on the walls

from travellers coming through here from India,

people from the British Empire, from America, from Europe.

All these travellers who came through here

from the 19th century onwards,

for them, Persepolis must have been their first gateway

to understanding Persia.

It wasn't just architecture that projected

Achaemenid wealth and culture.

These beautiful, decorative objects made of solid gold

are 2,500 years old.

This is the apex of sophistication.

We have objects of gold drinking vessels,

kind of like a sangria jug, I suppose,

in which you pour the wine directly into your mouth.

And we have cups that sit absolutely perfectly in balance

in the palm of your hand, in...chased in gold and silver.

We have jewellery upon jewellery of all the most semi-precious stones

that Persia could pile together.

Tales of the city's untold wealth grew in their telling.

And, soon, Persepolis became an object of Greek desire.

The decision not to fortify Persepolis proved to be its undoing.

The white marks on this pillar are a clue to what happened next.

When limestone is subjected to intense heat, it turns white.

In 330 BC, the Macedonians, led by Alexander the Great,

invaded Persia and burnt Persepolis to the ground.

Why did Alexander destroy Persepolis?

It wasn't about the wealth.

The Treasurer had offered him the city's riches

and Alexander spent two months looting them.

He burned Persepolis to the ground because it was a shrine

and the mother city of Persian culture.

Alexander wanted to obliterate Persian resistance and identity

once and for all.

With the destruction of Persepolis,

it was as if Alexander wanted to completely erase the memory

of Darius and the kings who once lived here.

And he succeeded.

They vanished entirely from history.

Centuries later, when visitors wandered the ruins

and encountered statues of strange, fantastical beasts,

they imagined that mythical kings, not the Achaemenids,

had ruled the Persian Empire.

By the 10th century, Abul-Qasem Ferdowsi,

the master storyteller I met in Tehran,

collected the tales of these fairy-tale kings

and put them in a book called the Shahnameh.

Ferdowsi's mythical version of Persia's history

doesn't credit Darius for building Persepolis,

but this godlike king called Jamshid.

So, who is Jamshid?

SPEAKS IN OWN LANGUAGE

According to the Shahnameh,

Jamshid is responsible for the creation of Nowruz,

the unique Persian New Year celebrated to this day

to mark the start of spring at the end of March.

There's even a theory that Persepolis was built

to celebrate this annual festival.

All over Iran, families set out a table like this

filled with seven symbols of prosperity and renewal,

including fruit, money, and, well,

the wine's been replaced by vinegar since the Islamic conquest,

but Nowruz is Jamshid's enduring legacy.

Jamshid was one of the first mythical kings in the Shahnameh.

He was responsible for many miraculous inventions,

including New Year, and he was able to do this, Ferdowsi tells us,

because he was possessed by a special quality called farr.

Farr could be described as a light.

It is God given.

It comes from above.

Radiance streams from the ruler.

Now, that's a metaphor, it didn't actually happen.

But when you see it in in the visual arts,

it's often shown in the form of a halo.

And we understand that,

we have a halo around sacred figures in Christianity.

Until recently, this symbol at Persepolis, a winged man,

was believed to be a representation of the deity worshipped

by the Achaemenids, the Zoroastrian God, Ahura Mazda,

the Wise Lord, the Lord of Wisdom.

Scholars now believe that this figure might actually be a visual

representation of farr, farr made flesh.

But this definition of kingship,

a king who rules with God's blessing, is double edged.

The king with farr rules well,

but the king who loses farr rules badly and can rightly be deposed.

When Jamshid became arrogant and started to present

himself as the supreme power, God in a way...

..he was punished and he was punished in the way that

the glory, or the farr, flew away from him in the shape of a bird.

And this says something, I think, about the Persian way

of thinking of history.

It's ever changing. It's always cyclic.

There is rise and fall, there is rise and fall.

It would be nearly 2,000 years

before archaeologists excavated Persepolis.

After deciphering the cuneiform language,

Darius and the Achaemenids

were restored to their rightful place in history.

Just a few kilometres away, there's another site that tells a similar

story, but with a surprise twist.

This necropolis was where

four Achaemenid kings

were brought for burial.

Their huge tombs are cut into the cliff face.

This is Darius' tomb...

..the king who built Persepolis.

Darius' hand is raised in recognition of his own imperial

farr which hovers before him.

The inscription reads,

"If now you wonder how many countries did King Darius hold,

"look at the sculptures and you will know."

If you count them, there are 26 men.

But, like at Persepolis,

the original events depicted here were forgotten

and replaced with stories from the Shahnameh.

Once again, real history was replaced by mythology

courtesy of Ferdowsi and his Shahnameh.

In the way Persepolis was actually founded by Darius,

but attributed to King Jamshid,

so this burial site was credited to another fantasy hero.

His carving is to be found just beneath Darius' tomb.

He's called Rostam.

That's Rostam there on horseback, on the right,

a warrior, a hero of incredible strength,

a kind of Persian Hercules.

With his great horse, Rakhsh,

Rostam rages through the first half of the Shahnameh,

defeating dragons, demons, and all the enemies of Iran.

He may not have much up top, but he's got plenty of muscle.

You can really rely on him,

so, he becomes a kind of foundation stone for the Shahnameh.

And the reason he can do that is that he just doesn't die.

So, his worst enemy is the White Div-e,

the absolute incandescent essence of evil.

Killing the White Div-e is killing the evil in all of us.

It is a straightforward moral victory.

Many Iranians know this site as Naqsh-e Rostam,

the Place of Rostam.

With cowering enemies kneeling before his powerful horse,

this figure looks every inch like the mythical hero of old.

It's easy to see why people came to believe these carvings portrayed

the exploits of Rostam, but none of them represent him at all.

In fact, they date from 500 years after Alexander the Great destroyed

Persepolis and the Achaemenid Empire.

So, if this figure isn't Rostam, who is he?

He is in fact another real Persian king, Shapur I.

And his story is to be found in the closing pages

of the Shahnameh.

The first half of the book is a sort of mythic preface,

where dynasties like the Achaemenids and the Parthians,

who followed them, are largely left out.

It's only towards the end where we encounter real history

and real kings like Shapur I,

who's from a Persian dynasty of rulers called the Sasanians.

So, this is the next kind of indigenous Iranian dynasty,

which Ferdowsi clearly sees as a good thing,

because they really are Iranian to their fingertips.

So, Ferdowsi spins this really interesting web of stories

around the historical figures of this Sasanian kings.

So, now myth and legend finally gives way to history proper.

I'm heading into the Zagros Mountains, in the southwest of Iran,

to find out more about the Sasanians.

It's an hour's climb.

But what's hidden there, I'm told, is unmissable.

And it is.

Seven metres high, chiselled out of a single stalagmite,

this is the very same king who was carved into the rock face

I saw earlier.

He was crowned in the year 240 AD,

Shapur I.

He looks like a God, doesn't he, with his crown, his flowing locks?

You can see that strong arm on his weapon belt,

staring out at the landscape.

But this is no God.

Shapur I is making a statement and setting out his Sasanian dynasty

to rule Persia for centuries to come.

In the Shahnameh, Ferdowsi talks about him as this great king.

He is the very embodiment of farr,

the divine right to rule appointed by God.

Like the pupil of an eye,

Shapur stands at the mouth of the cave,

looking out to cross his empire...

..determined posterity will never forget what he achieved.

Shapur ruled for over 30 years.

He built many cities during his reign,

but perhaps the most remarkable was the city he named after himself...

..Bishapur.

Unlike Persepolis, very little has been excavated.

But these lone commemorative columns bear witness to what was once here.

Written in Sasanian script is the declaration

of Shapur's brand-new city.

Under the Sasanians, Zoroastrianism became Iran's official religion.

Above ground, the crumbling remains of a fire temple

where an eternal flame once burned.

But below ground can be found a temple of quite another kind.

The most intriguing aspect of this underground temple

are the four corridors that run all the way around it,

with these channels clearly for flowing water.

And there's a direct link to the river,

which is why this site is thought to be sacred

to the water goddess Anahita.

This silver gilt plate absolutely captures the magnificence

of Sasanian craftsmanship.

It's the goddess Anahita, swimming surrounded by male attendants,

draped in ornate jewellery with her hair twisted into braids

and with her swelling hips very much a symbol of fertility, too.

It's a glimpse into an ancient Persia where women were worshipped.

Even in its ruinous state, you can sense the vaulting ambition,

the unshakeable confidence of Shapur.

But his greatest achievement wasn't building cities.

It was this.

Recorded in stone in a gorge nearby,

the epic saga of Shapur's triumphs over Rome.

In this remarkable relief,

you can see his victories against three Roman emperors.

First, he's trampling on the body of Gordian here.

He's also taking a truce from Philip the Arab.

And, behind, he's taking the Emperor Valerian prisoner.

And, as if to add insult to injury, above it all,

a Roman cherub handing him his symbol of victory.

But, unlike Gordian, Valerian was taken alive.

According to the Shahnameh, this is what happened to Valerian.

"Shapur flattened the evil Emperor's pavilion.

"His men set fires on all sides throughout the Roman camp

"and the sky seemed to come down to the Earth.

"They split his ears with a knife and bored a hole through his nose,

"in which they put a piece of wood

"of the kind by which a camel is led."

But this is Ferdowsi sidestepping real history.

It's true that Valerian was taken prisoner

and brought here to Bishapur.

But, after that, well, Roman historians have come up

with a variety of grisly outcomes, including the possibility

that he was flayed alive and his skin stuffed with straw.

But it seems more likely that he was treated well by Shapur.

Still, Valerian never went back to Rome.

After his capture, Valerian's legionaries were soon put to work

building Shapur's new city.

When Bishapur was excavated in the 19th century,

the city's surviving chambers were found decorated in mosaics,

like these, in the Roman style.

And when they weren't making mosaics, the legionaries were set

to work improving roads, dams and building bridges like this one

400 miles to the north.

A testament to Roman engineering,

much of the bridge still stands,

its crumbling arches a magnet for locals

who sit on the river's edge to relax and enjoy the warm summer evenings.

This is one of those places where I really feel Persia,

ancient and modern, meet.

Iranian families picnicking, paddling, speed boating

in the river against the ruins of Valerian's bridge.

Many kings followed Shapur

and these rock reliefs nearby depict his successors.

I know what you're thinking.

They all look remarkably similar.

From bronze sculptures, to coins, to stone effigies,

each king was portrayed Shapur style,

a crown set upon flowing locks.

The Sasanians were masters of marketing themselves

as Persia's new rulers.

But they had enemies.

In the north and east, tribal warlords, the Huns and Turks,

began to threaten the Persian Sasanian Empire.

To protect their borders, the Sasanians embarked

on their biggest-ever building project - a great wall.

It's long since disappeared, but the outline of the forts

that defended it have survived.

I'm standing on what remains of the Great Wall of Gorgan,

one of the greatest human defensive walls ever constructed.

It's on Iran's northern border with what is now Turkmenistan.

It's 1,000 years older than the Great Wall of China.

And, at 200km in length,

it's far longer than any wall the Romans ever built.

Built in the 5th century, the wall once stretched from the mountains

on Persia's eastern borders, to the Caspian Sea.

With a water-filled ditch dug in front,

this was a walled fortress protected by nearly 40 forts

manned by a garrison of soldiers

that some archaeologists have estimated to be around 30,000 men.

This mighty wall crossed plains,

hilltops and, in places, deep gorges.

It was an extraordinary feat of engineering.

Most of the wall had fallen prey to looters over the centuries.

So hardly anything remains.

But, if you know where to look,

there are sections that have survived.

Here, the wall crosses a river, and I've come to take a closer look

at the original brick structure

where archaeologists are hard at work.

Walking across the farmland up above,

I had no idea what I would see.

Now I've come down and I realise

I've walked down through levels of centuries in history,

there's six metres of topsoil I can now see that's accumulated

over the remains of what is obviously a well-constructed

military dam, and this fortification of real bricks.

You can see it stretching out, turning into the bridge there.

And it would have gone all the way up over those mountains.

And I just find it incredible to think this was the frontier

of the Persian Empire, stretching for 200 miles east and west.

And all that remains are a few, tantalising fragments.

I've come to meet archaeologist Dr Umrani to find out

more about its construction.

SPEAKS IN OWN LANGUAGE

The Gorgan wall is testimony to the engineering skills

and military organisation of the Sasanian Empire.

And, for 200 years, it kept the Huns and Turks at bay.

But, ultimately, the empire depended on the ability of its kings,

rather than a wall, to defend it.

No dynasty could last forever.

And the Sasanians were no exception.

According to Ferdowsi, the last few were a decadent bunch of kings,

whose cruel and evil deeds led to the decline and fall

of the Persian Empire.

Ferdowsi's aim in the stories of the Sasanian kings is to show again

that nothing is everlasting in Iran's history,

that kings can rule with farr and be aware of themselves and be aware

of their relationship to a higher power,

but how transient that can be.

The last years of the Sasanian dynasty were marked by years

of civil war in which four kings and two queens

ruled for no more than a few months each

before their lives ended in violence.

And, when they weren't fighting each other, the Sasanians were kept busy

guarding their northern and western borders against attack.

The sheer length and scale of the Gorgan Wall demonstrates

just how big a threat they faced.

In one sense, the Sasanian kings were right to build this great wall.

There was a tribal, nomadic army on the march.

A storm was heading this way.

But it was to come from the West.

They'd built this barrier in the wrong part of the country.

At the beginning of the 7th century,

far away in the Arabian Peninsula,

a trader named Muhammad began to receive

what were believed to be a series of revelations from God.

The revelations ultimately formed the basis of the Koran

and a small but radical movement would rise to change Persia

and the ancient world.

Islam was born.

SINGING IN ARABIC

# Allahu Akbar

# Allahu Akbar. #

It was a powerful idea, so powerful that, in a matter of decades,

the Islamic crusading armies decisively defeated

the Sasanian imperial forces.

The Arab invasion would be the greatest threat

the Persians had ever faced.

And the story of how they confronted it echoes to this day.

Next time, I'm going back to find out

how the Arabs conquered Persia...

..a conquest that was more than a confrontation

between two, mighty armies.

It was a clash between two, powerful cultures.

The Arabs brought with them a new culture,

a new language and a new religion.

But, despite subjugation and conversion,

Persian culture flourished.

The story of how Persia survived is one of the great chapters

in Iran's history.