Original subtitles

NARRATOR: In the immediate aftermath of the crucifixion,

the followers of Jesus numbered barely 100.

They were a persecuted underground cult on the verge

of being wiped out.

Yet within a few decades, this cult had thousands of followers

throughout the Roman Empire.

It spread through mighty cities like Ephesus,

where previously pagan worshippers had built

the Temple of Artemis, one of the wonders

of the ancient world.

It swept away the old beliefs.

It traveled as far as the deserts of Turkey,

to Cappodocia, where a mysterious people carved

underground cities and extraordinary churches

from volcanic rock.

And in the beginning, the message of Christianity

was carried on the roads that Rome had built for its soldiers

by one man, a preacher named Paul.

In his life, he walked 20,000 miles

bringing change and upheaval wherever he went.

Now, using the latest research and computer graphic imaging,

a team of experts will try to reveal the world that he knew,

the places that he traveled to and transformed.

This is the lost world of St. Paul and the first Christians.

[music playing]

36 AD in the city of Jerusalem Jewish leaders

are doing everything in their power

to crush a dangerous new cult, the cult of Christ.

Just three years after Jesus' crucifixion,

only a handful of his followers survives.

If they can all be killed, their religion will die too.

A conservative Jewish teacher presides over this persecution.

His name is Saul.

And he personally supervises the execution

by stoning of one of the Christian leaders.

Yet in time, this man will become Jesus' greatest

messenger.

More than half of the New Testament

is made up from his writings.

Many argue that without him, there would be no Christianity.

Saul became Paul and he shaped our world.

Now, our investigators want to uncover the world that

shaped him.

The story starts in Southwest Turkey,

in Paul's hometown of Tarsus.

It's still a busy town today.

But historian, Mark Wilson, wants

to find traces of the city that Paul knew

and which helped mold an extraordinary character.

MARK WILSON: It lies in the very fertile plane

with much agriculture in the area.

Textile production is prevalent in the area as well.

So as you look around Tarsus today,

it's a very prosperous and booming city.

NARRATOR: It's become a site of Christian pilgrimage.

This is the area on Tarsus where Paul lived.

And all pilgrims to the city visit this area.

NARRATOR: It's widely believed that this Well was in use

2,000 years ago and that St. Paul drank its water.

MARK WILSON: This would have been a water source

for his family.

Because of this, many people believe

this is holy water in the well.

NARRATOR: There's little in Paul's own writings

about his hometown but other sources reveal

a striking and significant fact.

Tarsus once stood on the shores of the Mediterranean.

The sea has since receded several miles.

But this was once a major port.

MARK WILSON: In the first century,

it was a very bustling city on a major crossroads.

And also note a university town, the Athens of the East.

NARRATOR: And just one block from Paul's will,

new evidence is emerging that gives us new insight into life

here at that time.

Recent building works were halted

when workers found ancient ruins buried right beneath the town

center.

Examining the find, the archaeologists

realized that they were looking at a row of stores,

an ancient mall dating back to the first century, Paul's time.

The walls of this excavation pit are marked with layer

on layer of artifacts.

Successive generations lived here.

But it's the discovery of a street at the bottom of the pit

that provides the biggest clue.

It's a paved road and it's dead straight.

Only one civilization built like this, the Romans.

Local archaeologist, Nadia Durgan,

points out other evidence of Roman occupation.

NARRATOR: As a port, Tarsus was wealthy.

That made it an attractive target for the Romans

and they occupied it in the decades before Paul's birth.

This Roman presence would have a major influence on the way

he would be brought up.

This street is amazing because the young Paul probably

played and walked along the street when he was

a boy growing up in the city.

NARRATOR: Archeological investigations

enable us to recreate what ancient Tarsus would have

looked like.

This was a busy commercial center.

Paul would have come into contact

with people of different nationalities,

different faiths.

MARK WILSON: Perhaps Paul came down here

and bought some groceries or traded in produce.

His family, of course, were leather workers, tent makers,

and they would have worked down in the central area of the city

as well.

NARRATOR: Tradition has it that his family were craftsmen

and traders.

They certainly had the means to give him

a privileged education.

He's raised a strict Jew and called

by the Jewish name of Saul.

But he's also a Roman citizen, something

which will prove advantageous throughout his life.

And he's taught Greek, the ancient international language

of diplomacy.

He grows up part of the establishment, a member

of a learned Jewish elite.

His first taste of travel is to Jerusalem.

He goes there as part of his education.

And this is where he first encounters the followers

of Jesus, a young revolutionary teacher whose popular support

makes him a major threat to the authorities.

To Saul, Jesus is the enemy.

In fact, he was so zealous that he was involved

in persecuting this new cult of people who are following Jesus

as the Messiah.

NARRATOR: There's no evidence that Saul ever met Jesus

but we know he considered his teachings blasphemous.

And after the crucifixion, he devoted his life

to wiping out his followers.

MARK WILSON: This was basically a nascent group

that was forming in cities throughout Palestine.

And Paul thought if he could kill and deprive

these communities of their leadership,

perhaps they could snuff out this new religion.

MARK WILSON: It is this background,

conservative, traditional, violently anti-Christian, that

makes the story of Paul's conversion all the more

remarkable.

The New Testament says that he pursued

a group of Jesus' followers who had

fled to the city of Damascus.

On the road, he was struck down by a blinding light.

It said that Jesus appeared to him in a vision

and Saul repented, transforming himself from that moment

on into a messenger of the gospel.

Well, certainly, his dramatic conversion

on the road to Damascus was the beginning

of his own spiritual journey.

Here, the persecutor now becomes the ardent follower of Jesus

as the risen lord.

NARRATOR: He continues on to Damascus where he is baptized,

taking the name of Paul.

And his mission begins.

Paul begins a journey that will last the rest of his life

and cover an estimated 20,000 miles.

It is made easier by the enormous network of Roman

roads.

We're walking along a section of Roman road about 10

miles north of Tarsus.

This gives us a good idea of what Paul experienced as he

traveled along these roads throughout the Eastern

Mediterranean region.

NARRATOR: These were being constructed by the Roman

military to make long distance travel as fast as possible.

Without them, the government of their vast and growing empire

would have been impossible.

The remarkable preservation of a Roman road like this

shows how well they were made.

We're looking here at the original stone pavement called

the meddling that was on the surface of the road,

as well as the original curbing.

NARRATOR: Roman roads are built to a strict formula.

First, the trench is dug, then packed with boulders and sand

to make a solid base.

This is topped with layers of smaller stone and clay.

And then paving stones, often made of basalt,

are laid on top.

They're slope so that rainwater runs into the guttering

at the sides.

Paul starts his mission in Antioch, the provincial capital

of Syria.

His followers there are the first people

to be called Christians.

And he then keeps moving through all the big cities

of the region, seeking the places where the old religions

are most powerful.

He will preach his message in the shadow

of the Temple of Artemis.

It is one of the wonders of the ancient world

and the biggest pagan temple on the planet.

In 52 AD, St. Paul comes to Ephesus, the fourth largest

city in the ancient world.

He is just one of tens of thousands

of pilgrims visiting the city.

Most have come to venerate the goddess, Artemis.

Artemis was the goddess of the hunt.

She was also the protectors of virgins.

And we know that during the yearly festivals,

this was a time when the young unmarried women would find

their spouses.

NARRATOR: Artemis was one of the most important gods

in Greek and Roman religion.

And here, she had a shrine to match her status.

The Temple of Artemis was known far and wide.

Its image was molded on the coins that

circulated the region.

This was one of the seven wonders of the world.

And in Paul's time, the largest temple in existence.

As a magnet for pagan pilgrims, it played a key role

in Paul's plan.

Ephesus became a wonderful base for him

because the Temple of Artemis was here

and he used it for his own benefit.

Because the many people came into the city

to participate in the various festivities

were an audience for him to preach the gospel to.

NARRATOR: Our investigators will reconstruct the Temple

of Artemis as Paul would have seen it.

The evidence suggests that the people of Ephesus

used revolutionary construction techniques.

But all that remains today are a few marble blocks recovered

from beneath 20-feet of silt.

EIREANN MARSHALL: To build this temple require

a monumental task.

Not only did they have to build it,

they needed to figure out how to build it.

They'd never done anything like this before.

NARRATOR: In their desire to honor their goddess,

the temples builders and engineers

set themselves a challenging task.

The decision was made to build the temple entirely

from marble.

And the nearest source of marble lay eight miles away.

It all had to be transported back to the construction site.

Archaeologist Julian Bennett is seeking

to discover how it was done.

Gangs of men will be working with metal chisels and hammers,

all the way around to create another turf less than six

inches wide.

You can still see the surviving turf there.

And then once they got the channel down

to the level of the block they wanted,

if you came from the side, you hit it with steel wedges

and the block would lift off.

NARRATOR: An estimated 51,000 tons of marble were needed.

The Ephesians didn't do the hard work themselves,

they delegated it to slaves and criminals.

A common punishment for crime was

to be sentenced to work in the quarries.

You weren't expected to live too long and you probably didn't.

NARRATOR: Once they'd carved out the blocks,

they still had to get them to the temple construction site.

In the 21st century, quarrymen rely on heavy machinery.

A few yards from the ancient quarry,

gray marble is still being extracted from the same site.

The average block is 13 tons, about the same size

as the blocks used to build the Temple of Artemis.

Today, a machine makes it look easy.

When the temple was built, sheer manpower.

NARRATOR: But the temple architects

used all their ingenuity to speed up the process.

They invented a method that would make them better stone

movers than even the Egyptians.

They turned the square blocks into wheels.

Wooden cradles were built around the cut rocks

so that it could easily be rolled the eight

miles into town.

Once they had the raw materials, they

could set about building one of the greatest temples the world

has ever seen.

In its heyday, it would attract more pilgrims than the temple

of the Jews in Jerusalem.

Today, the site where it once stood is a flooded marsh.

It's hard to imagine why such a huge temple would be

constructed here on a piece of land

no modern builder would touch.

The Roman historian Pliny claims the marshy ground

was chosen as a precaution against frequent earthquakes.

It would cushion the tremors.

Another theory is that a meteor landed here.

The ancients thought it was a god sent from heaven

and constructed their temple around it.

Either way, the location presented the builders

with a serious problem.

How to construct what would be one of the wonders of the world

in a swamp?

They started by creating a dry base,

treading down a layer of charcoal,

then covering it with sheep fleece

to prevent water rising up.

Slate blocks were put on top.

The floor of slate and marble was built 8-feet high

to stay above the water level.

It spanned an area 255-feet wide and 425-feet long.

This sturdy platform supported a forest of columns.

This one is 45-feet high, but Pliny

reveals that the originals were a massive 60-feet, 6 stories

tall.

To achieve this ambitious engineering task,

the architects used scaffolding.

They assembled the columns from a series of stack drums,

each weighing more than eight tons.

A column consisted of around 30 drums.

And once assembled, they were flooded with hammer and chisel.

This was done an incredible 127 time.

Amongst the ruins, Eireann Marshall

finds evidence of how they built the temple roof.

So having gotten the columns up,

now you had the task of actually erecting the lintels.

The lintels are all those stone blocks which you have

to put on top of the columns.

NARRATOR: Again, it's Pliny who tells us how the lintels were

positioned.

It was crucial to get it precisely right.

What they did was they erected a ramp of reed bags

all the way up to the level of the top of the columns.

Then they placed the lintels on top of them

and then poked a hole in the reedbags

so all the sand came out.

Slow enough so that the lintels could be adjusted.

And you have to bear in mind, these aren't mortared,

they have to be exact.

NARRATOR: It took 120 years to complete the temple.

We can now bring to life this incredible part of St. Paul's

lost world, an astonishing building that was bigger

than anything that had gone before.

It was the focal point of huge activity,

all centered around the cult of the goddess.

And awning in the roof bathed her statue in light.

And the cult of Artemis was by no means

the city's only religion.

The Romans believed in many gods and they

tolerated the traditional beliefs

of the peoples they conquered.

So at first, Paul and his new religion are well received.

And a few miles from the temple in the city center,

Paul discovered something that will allow

him to deliver his message to an audience of unprecedented size.

We're entering one of the most spectacular buildings

in Ephesus.

25,000 people came here for games and for protest.

St. Paul entered here.

NARRATOR: The city's theater, also built from white marble,

was undergoing expansion while Paul was in the city.

459-feet across, containing 66 rows of seats,

it was once the largest theater in the country.

Paul would have come here and address one of the biggest

audiences of his life.

This was the perfect theater.

It seated 25,000 people and acoustics

allow for a dramatic impact.

NARRATOR: The superb acoustics derive from the design

of the theater seating.

These seats are wider.

And the further up you go, they're narrower.

And this concave shape helps to retain

the sound in the theater.

NARRATOR: But the theater wasn't designed simply

for speeches and plays.

The partition that shields the front row

indicates that Paul shared his stage with more dangerous

entertainment.

The wall is high to protect the spectators

from the death and the blood and the guts of what went on here.

NARRATOR: The recent discovery of a dedicated graveyard

in Ephesus confirms that this theater was an arena where

gladiators fought.

These immensely popular contests drew large audiences.

And as far as Paul was concerned,

the gladiator games attracted even more people

to hear his message.

Because what separated St. Paul from Jesus's other disciples

is that he doesn't just target Jews,

he aims to convert people of all faiths.

His methods would cause Christianity

to become a worldwide religion.

Ultimately, they would bring about the downfall of the Roman

Empire.

And yet it was the Roman's own engineering skill

which gave St. Paul the opportunity he needed.

St. Paul lived and preached in the city of Ephesus, part

of modern day Turkey, for 2 and 1/2 years.

The largest city in Roman Asia with an open minded

and cosmopolitan population, it was the ideal place

to seek new converts.

Archaeologist Julian Bennett discovered

that the way the Romans built their towns

gave Paul a unique chance to bring huge numbers of people

to Christianity.

But he also finds that this city had its eye fixed

on more otherworldly pursuits than theology

and a new religion.

Well, everyone in the city would have had a brothel.

This is an everyday fact of Roman life.

NARRATOR: Paul is in a city with a reputation for pleasure

seeking.

JULIAN BENNETT: A male dominated society

when a young man would not marry until he was in his mid 20s

or 30s.

A place like Ephesus, the heart of the city,

would have had several brothels.

NARRATOR: Right in the center of town,

early archaeologists found an intriguing signpost.

It featured a foot and a heart.

This particular building when they excavated it

in the 19th century, they found a number of oil lamps

here with scenes of erotic art on them

and also an inscription referring to young people.

And so the excavators came to the natural conclusion

this was the main brothel of Ephesus.

It occupies such a prominent corner.

NARRATOR: Prostitution was an important source of income

for the Roman administration.

We even know that prostitutes pay the tax to the city

and to the government.

And that this tax was the equivalent of one sexual act

and they had to pay this tax every month.

NARRATOR: But it wasn't just about pleasure.

The fundamental challenge for the town administrators

was providing vital amenities for over 200,000 people.

The most important was running water.

The city source was eight miles away in the Meandros Valley.

Diverting it into Ephesus required an extraordinary feat

of engineering.

Well, here we have it.

This is the aqueduct bridge for Rome and Ephesus.

This was built something like 2,000 years ago

before the time of St. Paul's visit here

but it's still an incredibly good condition.

NARRATOR: An aqueduct this size needed funding beyond what

the city could pay for but it gave politicians a chance

to gain favor with the masses.

It gives us the name of the man, Gaius Sextillius Pollio,

with his wife, and also, their son.

For the people of Ephesus, [non-english speech] We pay

for this from our own pocket.

It is a way of making certain the people of Ephesus remember

who you are, or perhaps, more to the point,

when election time comes around again, remember my stepson.

NARRATOR: Whatever their motive, the private individuals

who paid for projects like this did a great service

for the city.

Pollio's aqueduct carried vital water supplies into Ephesus,

where they entered an elaborate cistern.

This is precisely the sort of thing

we're looking for when following an aqueduct.

And they're absolutely jam-packed with calcium

carbonate, and it's calcium that's been dissolved out

of the water coming down with the aqueduct

through these limestone hills, come into the city

somewhere in this area, onto this structure.

And over here, a section which has been broken loose.

If I can lift this, you have the flange

at one end, socket at the other end.

The flange would always be on the downstream side.

So a very good example of Roman technology.

NARRATOR: Pipes like these ran in a network down the hill.

There were 100 gallons a day for each Ephesian,

comparable to the provision made in most modern cities.

Paul and most other citizens got their water

from communal fountains, but some buildings

were supplied directly.

One was the bathhouse.

The Roman baths were the focal point

of the city's social life.

Here, the Ephesians discussed politics, philosophy,

and Paul's religious ideas.

Christianity spread by word of mouth,

and it was from places like this that Paul's message began

to pass to a wider audience.

The bathhouses were places equipped with what was then

high technology, including an underfloor heating

system called a hypocaust.

And we are, in fact, very lucky at this particular point.

This is a very good, preserved cross-section

of a typical hypocaust system.

So you can see the pillars here, which support the main floor.

A very thick, very hard pink Roman plaster

known as opus signinum.

It retains heat.

On top of this, we're very lucky.

Marble slabs from the floor.

NARRATOR: Hot air flooded the underfloor space

spreading up the walls to heat the room from all sides.

Hot water was piped into the bath.

The dirty water from the bath house was put to good use.

It flushed out waste from other buildings.

And just next door is one of the most important facilities found

in any large Roman city.

JULIAN BENNETT: And sure enough, a really nice Roman public

latrine.

Marble seats, nice and cool in the summer.

Not so nice, perhaps, in the winter.

And you would sit here next to your neighbor, talk

about the weather, gladiatorial games, what life was like.

You have a nice little water trough in front

because the Romans did not have toilet paper.

Instead, every Roman carried a personal sponge

and they would have the sponge on the end of a stick,

dip it in the end of the water, and now, you

see what this is for.

NARRATOR: Our evidence for this comes from an unusual source.

JULIAN BENNETT: We are told one gladiator,

rather than go out and fight his opponent,

decided to commit suicide.

And he did so by making the excuse of going to the latrine

and grabbing hold of the sponge and choking himself

to death with this.

So that's how we know about the sponges.

NARRATOR: While Paul would have used these public restrooms,

the upper classes had the privacy of their luxury homes.

Today, the remains of these lavish houses

are protected in a climate-controlled shelter.

Saint Paul would have seen them being built and furnished

in exotic marble brought from across the Roman Empire

to advertise their owners' wealth.

Each house had a private bathroom constantly

flushed by the continuous flow of the aqueduct system.

This is a very high quality latrine.

Small, private latrine.

We know in Rome, at least, we assume in Ephesus as well,

they had different sized water pipes

and they calculated the tax you paid by the size of your water

pipe.

So to have a private toilet like this is very much

a sign of status.

NARRATOR: The wealthiest households could even

afford an early form of air conditioning, walls of water.

JULIAN BENNETT: You to water every day just to stay alive.

You need water for washing, for cooking,

but it helps to cool down the air as well.

So all in all, this must have been an extremely pleasant

place to be in, especially in the middle of the summer.

NARRATOR: The Ephesian ruling classes enjoyed high quality

of life, and suddenly, Paul threatened to disrupt that.

Not only did he undermine their pagan beliefs,

but with it, he damaged the city's most important trade.

Religion was big business in this Ephesus.

Its market fed off pilgrims to the temple.

Silver statuettes of the goddess Artemis

sold as charms brought in vast revenue.

But the arrival of Christianity meant that people were turning

their backs on Ephesus.

25,000 people gathered in the great theater

to hear a silversmith call Demetrius speak.

He told them that Paul was not only insulting their goddess,

but also, threatening their main source of income.

He stirred the crowd to the point

where an anti-Christian riot erupted.

Tradition has it that to appease the angry mob,

Paul was thrown into prison.

It's thought that was where he would write some

of the letters that would make up so much

of the New Testament.

On his release, he was told to leave Ephesus.

But his new religion had already taken hold.

The city was becoming a city of Christians.

And the silversmith Demetrius was right.

The city of Ephesus declined with the cult of Artemis.

It was the beginning of a long, slow collapse that will see

the temple fall into ruin.

Paul moved on.

His message would have an equally powerful effect

elsewhere.

It would reach to the very furthest parts of the Roman

Empire, transforming every community it touched.

Next, we investigate the religious society that sprung

up in the wake of Saint Paul.

In the strange land of Cappadocia,

a mysterious group of Christians would seek safety

by building a secret world underground.

15 million years ago, a series of volcanic eruptions

around the Mediterranean threw up immense clouds of ash,

blanketing the land layer upon layer.

Over time, this created a bizarre otherworldly place.

Today, it's called Cappadocia.

Some scholars believe that Saint Paul came here

to preach his new religion.

Our investigators are trying to understand the part

that this alien landscape played in the birth of Christianity.

And the best way to see what traces remain is from above.

It stretches over 15,000 square miles.

It's dotted with sculpted cones, pyramids, and obelisks.

The ash is up to 300 feet thick.

Each layer is of a different consistency,

and this means that erosion by wind and rain

has created a remarkable, uneven terrain.

Early explorers thought the shapes must have been carved

by some ancient race.

The buildings do show the skill and craftsmanship of a highly

sophisticated people.

Their works can still be seen, and it still impresses.

These are some steps there cutting into the rock,

leading up to somebody's habitation.

It's an incredible gorgeous place.

Beautiful.

NARRATOR: The word Cappadocia derives from the Persian

for land of beautiful horses.

The Cappadocians were famed as suppliers of prize animals

for the Roman army.

Down on the ground, Veronica Kalas chooses the best form

of local transport and heads for the Ihlara Valley,

a canyon cut deep into the ash.

She finds an extraordinary concentration

of ancient churches carved into the rock face.

There are over 100 of them in this 10-mile valley alone.

It's clear that Paul's message had an immense impact.

The churches are decorated with frescoes that depict stories

from the New Testament.

Veronica wants to trace Paul's story back further.

She heads for a settlement a few miles north of the canyon

to try to discover how early Cappadocians lived.

What Paul would have come across was an extraordinary community

of cave dwellers.

This settlement has long since been abandoned,

but its ancient inhabitants left behind tantalizing glimpses

of their lives.

It's a large, square room, and it has a conical vault

that leads up into a ventilation shaft.

NARRATOR: There's a chimney.

They lit fires here.

This is most likely where they cooked.

This is an oven with fire burning down below and perhaps

a grill.

NARRATOR: To the trained eye, another room

reveals evidence of industry.

VERONICA KALAS: This is known as a pit loom.

And this is a fine example where you might have a wooden frame

erected around the sitter's lap in order to weave textiles.

NARRATOR: There are also pits for storing clay jugs

or amphoras.

Using these clues sculpted 2,000 years ago from ash,

Veronica is building up a picture of what

the Cappadocians were like.

VERONICA KALAS: The people who lived

here were said to be very rugged,

the cowboys of the empire.

And there's a story that when a biker would

buy the Cappadocian, the viper would die.

This is how tough the Cappadocians were.

NARRATOR: And yet, living on the trade route between Europe

and Asia, these people were becoming rich.

The Cappadocians' lifestyle was sophisticated and comfortable.

A large ceremonial hall indicates the high status

of the people living here.

Most of the ancient world's freestanding buildings

have long since crumbled away, but Cappadocia's volcanic ash

retains a record of its architecture.

It offers a unique glimpse of the lost world in which Saint

Paul operated.

And there is clear evidence that his religion gained a foothold

here.

This is a really nice church.

It's in a basilica style with columns and piers

and arcades separating this very large barrel-vaulted nave

from side aisles.

And here, we're entering into the sanctuary

where the altar should be.

NARRATOR: Although these columns appear to have been built

from bricks and mortar, they are actually

cut from the volcanic ash.

Their elaborate style simply mimics the building techniques

of the time.

Ash is easily worked with simple tools,

but hollowing out a sophisticated home like this

would have taken many months and a great deal of skill

and planning.

Veronica has analyzed each of the 15 rooms here,

and now, using computer graphics,

we can reveal the complex structure of this settlement.

This residence is the largest and most

elaborate in Cappadocia, covering 3,000 square yards,

about half the size of a football field.

The kitchen, ceremonial halls, and church mark it out

as an estate for the elite.

It was home to a large, aristocratic, and publicly

Christian family.

This place is part of Saint Paul's legacy.

The architectural details of the Church of Durmus Kadir

have been remarkably well preserved.

They give us a rare insight into how early Christians

worshipped.

VERONICA KALAS: This is a nice representation

of the kind of church that emerged immediately

after Saint Paul's times.

There's no paintings here, and yet, the architecture

is very, very elegant.

[music playing]

You can imagine what an amazing place this would have been

around the fourth to the sixth century.

This was known as an ambo.

That is a pulpit.

This is a very important feature in early Christian churches.

So this is the closest thing we have to the time of Saint Paul.

They mostly stood then.

It seems that people prayed with their hands

open and their chest up to the sky, not bowing down

and closed.

NARRATOR: The congregation stood around

the ambo in the nave facing the altar in the central apse.

To left and right were side aisles

containing a baptismal font.

Behind them was the church entrance, the narthex.

Today, it is lined with empty tombs.

But it was not always easy for the Cappadocians

to hold on to their Christian faith.

The more the early Church grew, the more

Rome saw it as a threat.

So it went literally underground.

Next, we reveal the extraordinary subterranean

world created by the Cappadocians

to provide shelter and safety for tens of thousands

of people.

For 30 years, Paul traveled the Roman world

spreading the message of Christianity.

His journey entered its final phase in Jerusalem.

Around 60 AD, he was arrested for a breach of Jewish law.

He faced death, but exercised his right as a Roman citizen

to go to trial in Rome itself.

This was a dangerous gamble.

The Roman emperor, Nero, saw Christians as a threat.

By the mid 60s, the situation of the Christians in Rome

was quite precarious.

The Romans recognized that they were not a sect of Judaism,

but were a separate religion.

NARRATOR: And when fire engulfed the city, destroying hundreds

of buildings, Nero needed someone to blame.

MARK WILSON: After the fire in Rome in 64,

Nero was looking for a convenient scapegoat,

and he pointed to the Christians as the cause of the fire,

and this brought great persecution.

NARRATOR: Paul was well-known as a Christian leader.

Tradition says that Nero singled him out.

He had him beheaded.

But he couldn't kill Paul's message.

In the lands where he had preached,

the Christian faith had taken root,

and slowly, over centuries, Christianity

came to rule the Roman Empire.

In 313 AD, the Roman emperor Constantine became a Christian.

The pagan gods were swept aside, their temples

destroyed, replaced with the first Christian churches.

And yet, that golden age is short-lived.

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It meant the fate of the empire and the church became linked.

Christianity grew while Rome remained strong,

and when Rome declined, her enemies

became the church's enemies.

This shift in fortunes was felt even

by the remote cave-dwelling Christians of Cappadocia.

By the fifth century AD, as Rome fell,

they found themselves at the mercy of Arab warlords.

They had no means to fight back.

They took an incredible course of action.

In their tens of thousands, Cappadocia's Christians

went underground.

It wasn't until the 1960s that this extraordinary story

was revealed.

The chance find of a secret passageway led to a series

of bizarre discoveries.

Beneath this landscape are hundreds

of miles of manmade tunnels.

Their entrances are incredibly well-hidden.

But opening these cunningly concealed doorways gives us

a new insight into the story of the first Christian's.

Investigations have revealed that the tunnels formed

self-contained settlements with all the features

of a sophisticated society.

People survived down here thanks to ingenious ventilation shafts

carved into the rock.

VERONICA KALAS: It's quite amazing.

If you stand here, you feel a breeze.

And we are several meters underneath ground level.

In fact, they reached the water table.

So these function both as ventilation shaft and as wells

to pump water from down below.

We have a large square, what looks like a room,

but, in fact, it's a den for grapes,

and the grapes would be pressed.

And so wine, the liquid from pressing,

would come through here and then be deposited in this rock cut

space here.

NARRATOR: Life underground cannot have been easy.

It's hard to imagine how these people survived without seeing

the sun.

They didn't have a sense of day and night down there,

and I think that must have created some very strange

psychology in people.

NARRATOR: They were clearly desperate.

They secured the entrances to these complexes

with heavy wheel-like doors.

Some remain sealed to this day.

And 2 stories down, there's hard proof of what drove them here.

VERONICA KALAS: This is what looks like an altar.

We don't really know why this is here in the middle.

The altar usually is in the apse.

To apses side by side, that's how we know that it's a church.

NARRATOR: They'd been forced underground

because of their faith.

It was natural that they would build altars to worship.

40 settlements like this have been discovered.

The largest is 8 stories deep, sinking 90 yards underground,

with 20 miles of tunnels.

It's believed that up to 20,000 people could hide in this one

complex alone.

And it's believed that there are many more such networks still

to be found.

It would be another five centuries before peace return

to this region.

For 300 years, Christians used these tunnels

and endured enormous hardship to preserve their faith.

That faith was Saint Paul's legacy.

Paul's role in early Christianity

has been said by some to be really the founder

of Christianity.

But really, the message he proclaimed

was that of Jesus himself.

He wrote half of the New Testament.

13 books are attributed to Paul.

He established churches all the way from Antioch to Rome,

and these became the foundation for later Christianity.

NARRATOR: Saint Paul spent a lifetime traveling

through the cities of the ancient world.

He challenged the might of the Roman Empire.

When he began, Christianity was a faith

in danger of extinction, but through the efforts of this one

man, it not only survived, but flourished to become one

of the world's major religions.

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