Divine Gamble Rome: A History of the Eternal City

'Rome. Holy city.'

'Blessed by Pagan gods.'

'Earthly capital of a glorious empire

'with a divine mission to conquer and rule.'

But Rome was to cast aside its pantheon of idols

to embrace a revolutionary new faith from the East

that would change its classical skyline forever.

'Personal salvation and the worship of one God

'eclipsed the gods of old.'

'Soon after the crucifixion of Jesus his message started to spread...

'but there was nothing inevitable about its ultimate triumph.'

'The followers of Christ were viciously persecuted.'

'But the martyrdom of St Peter gave Rome a new founding story

'and a divine mission for his successors, the Popes.'

Rome became a vibrant centre of Christian devotion.

But it was the necessities of power

that really decided its sacred destiny.

'I've come as both historian and tourist,

'to examine how the decision of one emperor

'changed the history of Western civilisation and Rome itself.'

'Its impact on the fabric of the city

'and on the lives of its citizens, nobles and high priests.'

'Abandoning paganism risked everything that Rome stood for.'

'Triggering confusion, violence, power struggles,

'and setting Popes and Emperors on a collision course.'

So what transformed the Holy City of Rome from the pagan heart

of the Roman Empire to the capital of Christendom?

'On the outskirts of Rome, a stadium once stood.

'Horse-races were staged there to entertain Emperors and citizens.'

But in 64 AD the imperial race-track became the site of a mass execution.

'The centre of Rome had been devastated by fire.

'Angry Romans wanted someone to blame.

'So Emperor Nero offered them a new religious sect - the Christians.

'Some were torn to pieces by wild dogs,

'others set on fire as human torches,

'and a few were crucified.'

Amongst them was Peter, a leader of the Christian mission in Rome

and one of the original 12 disciples.

Tradition says that out of respect for Jesus,

he asked to be crucified upside down.

'In the centre of the race-track stood an obelisk.'

This is that same obelisk, and 2,000 years later,

it's still in roughly the same place.

It was probably the last thing that Peter saw.

And this is probably the last thing that he could have imagined.

St Peter's, the magnificent basilica built in his honour

and still towering over the city of Rome.

'Ultimately, Peter's execution would transform Rome.

'But when he died, Christianity was just one of many Eastern cults,

'struggling to survive, in a city dominated by pagan gods.

'For a thousand years, paganism had brought success and prosperity

'to the Eternal City.

'The will of the Gods decided every aspect of Roman society.

'When it went to war. Who its rulers were.

'Paganism had brought Rome domination of the ancient world.'

The Roman Empire was flexible, embracing and co-opting

foreign gods into its own state religion,

but so far none had threatened the status quo.

'But Christianity was radically different.'

# Gloria

# Gloria. #

'Whereas paganism sought the goodwill and protection

'of the Gods in this life,

'Christianity held out the promise of eternal life in the next world.

'But its rejection of pagan practice marked it out.'

The Christian refusal to sacrifice to the ancestral Gods

in honour of the Emperor

made them a potential threat to the Roman state itself.

'As Christianity took hold amongst Rome's under-classes,

'the pagan establishment sought to discredit it.

'The ritual of Holy Communion, the taking of Christ's body and blood,

'was described as cannibalism.'

'Yet, meeting in secret, the Christian community began to grow.

'Historian Alexander Evers is taking me

'to one of Rome's remaining house churches from the second century.

'What took place in private dwellings like this

'would sow the seeds of Rome's unique Christian future.'

So what was the early church in Rome really like?

Initially, you can safely say it was an unorganised heap of people.

Hardly any structure there. A large group. A growing group within Rome.

But not united. There are differences of opinion

about how to worship, where to worship.

And eventually, gradually, you have those single figures of authority

rising to the fore.

The Bishop, who can pull it all together.

So where did the early Bishops of Rome get their authority from?

From a fairly early point onwards,

they're beginning to place themselves in one line

with the apostle, Peter, who was the right hand of Christ,

who supposedly was the first Bishop of Rome.

Where that tradition comes from is not entirely clear,

but that tradition, "I'm the successor to Peter",

gives them an enormous source of authority.

# Sanctus

# Sanctus. #

'The lineage of Bishops from St Peter

'is known as the apostolic succession.

'It's the bedrock of the Bishop of Rome's authority

'and papal power to this day.

'But in the third century, the Bishops were leaders

'of a religion on the margins.

'And that's why I'm heading to the outskirts of Rome,

'and the catacombs of San Callisto.

'Deep within its maze of underground corridors,

'there is something hard to find, and yet very important.

'Early evidence of how the Bishops of Rome got their unique title.'

This reads PP, which stands for Papa or Pope,

and it's the first example we have of an inscription

that refers to the Bishops of Rome by that title.

At the time, any charismatic bishop anywhere in Christendom

might have been known as Pope, but gradually, the Bishops of Rome

came to be known by that name, though, surprisingly,

it wasn't for almost 800 years, until the 11th century,

that it became official.

'But there is something else down here that I really want to see.

'Some of Rome's very first Popes

'were buried in these subterranean tombs.'

What an extraordinary room this is. This is the crypt of the Popes,

and nine of the Bishops of Rome are buried here,

dating all the way back to the early 3rd century.

It's an extraordinary thought that these men

were the leaders of Christianity, right at the very beginning,

long before the Papacy became the office of power,

magnificence and wealth that we know today.

'But some of these Bishops, just like St Peter,

'were to die for their faith.'

Sixtus II was celebrating mass right here at the altar,

when Roman soldiers burst in.

When they drew their swords, the entire congregation competed

to offer themselves for the honour of martyrdom,

at which Sixtus pushed himself forwards, bared his neck,

and begged them to take his head.

The soldiers were happy to take him up on his offer.

They beheaded him on the spot.

'The persecution of the Christians wasn't constant.

'When the Roman Empire prospered,

'the church was reluctantly tolerated.

'But in the mid 3rd century,

'the empire tottered on the edge of catastrophe.'

Rome faced 50 years of disaster.

Civil wars, invasions, and a bewildering succession of emperors.

The cracks in the imperial edifice seemed terminal.

'Some emperors believed that Rome was being punished

'for turning a blind eye to the Christians.

'The unity of city and empire was at stake.

'Something had to be done.'

In 303, the Emperor Diocletian

launched the bloodiest persecution to date.

'Churches were destroyed, bishops decapitated.

'The streets were awash with the blood of the faithful.

But the killings failed.

The persecutions merely served to promote and advertise

the faith of the martyrs.

The flame of Christianity could not be extinguished.

'Diocletian's victims would forever leave their mark on Rome.

'And remarkably, one has been preserved to this day.

'This figure, one of the city's least known

'but macabre sights, appears to be a statue.

'But closer inspection reveals something far more spine-chilling.'

When at first you look at this, you think it must be a waxwork.

But when you look a little closer into the slightly open mouth,

you see through the open lips of the skeleton.

And if you look at the hands, on the outside, they appear to be wax,

but look inside, you can see not just the skeletal bones

of the real hand and the body,

but actually the dried skin there, too.

This is the body of Saint Vittoria.

'The cruel deaths of the martyrs didn't destroy Christianity.

'Their stories kept it alive.

'But it was still just one of many religious sects

'on the edges of Roman society.

'Only the whim or faith of an emperor

'could change the course of history.'

'Emperor Constantine was a ruthless general

'who slashed his way to power.'

He was a harsh warlord, capable of terrifying violence.

He even executed his own wife and son.

But he was also a visionary, who in one decision

changed the entire course of Western civilization.

'No-one knows for sure

'why Constantine chose to embrace Christianity.

'But the decisive revelation took place here at Milvian Bridge

'on the outskirts of Rome.'

'The over-extended empire had been split in two - East and West.

'Rome was no longer the imperial capital.

'Each region was ruled by an Emperor and his deputy.'

Constantine shared the West with Maxentius,

but they soon became bitter rivals.

'In 312, Constantine had cornered Maxentius' forces

'on the banks of the Tiber.'

Before battle commenced, Constantine had a vision.

He saw the sign of the cross superimposed on the sun

with the words "By this sign, thou shalt conquer".

At the very last moment, he ordered his soldiers' shields

to be emblazoned with the cross.

Fighting under Christian banners,

he won the greatest victory of his life.

'Constantine now saw Christ not as the crucified lamb of God,

'but as a potent God of victory.

'He was about to turn his back on everything that had made Rome.'

'Exchange the protection of many gods for just one.

'Overturn a thousand years of Roman history,

'and embrace the faith of persecuted radicals.

'But could Rome withstand this revolution?

'Constantine was willing to take that gamble.

'But while an Emperor could change his religion overnight,

'Rome's pagan citizens would take longer.

'The arch built to mark Constantine's victory

'shows how controversial this change of policy was.'

This arch contains a surprise.

If you look up here on line three, you'll see the divinity

that Constantine thanks for his victory is subtly ambiguous.

It could be either Christian or pagan.

'Constantine doesn't give thanks to the pagan god of war,

'but neither does he reveal his new faith.

'He uses a general term for divinity - divinitas,

'which was acceptable to both pagans and Christians.

'Promoting Christianity in a world where the majority was still pagan

'would need tact and diplomacy, even from an all-conquering emperor.

'Constantine's cautious approach to conversion is reflected

'in the 4th century church of Santa Pudenziana.'

The facade of this church wouldn't have looked

at all out of place in pagan Rome.

It's a basilica, literally, a king's hall,

and this was the typical rectangular building of Roman public life,

where emperors and governors held court.

'The need to fit in is further revealed when you step inside.

'The image of a humble saviour has received a grand Roman makeover.

'Jesus isn't nailed to the cross like a common criminal.

'He's depicted ostentatiously on a throne, like a king or an emperor,

'and his disciples are dressed in the togas of the aristocracy,

'like senators holding court in a classical city.'

Pagan Romans coming in here wouldn't have been shocked

or put off by anything they saw.

But this wasn't the lower-class, radical religion

of the early church.

This was imperial Christianity, designed to attract and impress

Romans high and low.

'Christianity was becoming Roman.

'Rome was becoming Christian.

'But Rome's rebirth as a sacred city of Christendom

'required a transfer of holiness

'from Christianity's first holy city.

'Constantine dispatched his mother, Helena,

'on a pilgrimage to Jerusalem.

'Helena returned with a precious collection of Christian relics.

'And I'm just about to witness

'the most monumental treasure of them all.'

This is one of Empress Helena's most extraordinary finds.

The Scala Sancta.

This staircase is believed to be

from the palace of Pontius Pilate in Jerusalem.

Jesus walked down these steps after he was sentenced to death.

'Unlike the remote pagan Gods,

'the Christian God had a son whom he had sacrificed for humanity.

'And what Christ had touched, his followers also wanted to touch.'

For centuries, pilgrims have climbed these steps on their knees

as an act of piety, to get closer to Christ and honour his suffering.

It's not often, in our secular age,

that you see a place of such intense, passionate devotion,

but this tells you something about Rome as a holy city.

A holy city is a place where God meets man.

And that is exactly what these pilgrims are doing.

While Helena was importing holiness from Jerusalem,

Constantine was keen to promote the city's home-grown Christian sites.

But he had to be careful.

Rome was still overwhelmingly pagan,

and that's why he built his first churches away from the centre.

'Constantine built seven churches in Rome.

'But one took on supreme importance.

'Nero's Circus had become a holy place for Rome's Christians,

'as the location of Peter's crucifixion and burial.

'A simple shrine had been erected over his grave.'

Constantine recognised the importance of the site.

A direct link between Rome and Jesus Christ himself,

through his right-hand man, Peter.

So Constantine decided to build his biggest basilica over Peter's tomb.

'Constantine's basilica gave Rome's Christians

'a new focus for devotion.

'It stood for over a thousand years,

'until it was rebuilt during the Renaissance.

'Jesus said that Peter would be the rock

'on which his church was built.

'Constantine's basilica literally fulfilled that prophecy.

'Over the centuries, St Peter's was to become the cornerstone

'of the Catholic Church

'and the headquarters for an empire of Christian souls.

'But when Constantine commissioned it,

'it was still an act of wishful thinking.'

Constantine's St Peter's promoted Rome as a Christian centre.

But he died leaving a hybrid holy city,

part Christian, but part pagan.

'The temples of the old Gods still dominated the skyline.

'Pagans still dominated the city.

'Constantine's divine gamble now lay in the hands

'of Rome's new high priests.'

It was now down to the Popes, Rome's Bishops,

to really make Rome Christian.

BELL TOLLS

Before Constantine, Rome's Bishops had been persecuted leaders.

Now they were important officials with real influence.

One Pope, Damasus I, revelled in this new status.

Nearly 70 when he came to power,

Damasus didn't allow old age to dampen his pleasures.

Corrupt and egotistical, his enemies described him

as a smooth-talking adulterer, or as they put it,

"A tickler of the ears of middle-aged women."

'But Damasus was also a poet

'who used his literary gifts to win Christian souls.

'He took Rome's earliest sites of martyrdom

'and celebrated them in poetry.

'This poetical propaganda has been studied by Marianne Saghy,

'an historian who I'm meeting at the Church of Sant' Agnese.'

Pope Damasus went into every single catacomb, more than sixty catacombs,

placing poetic inscriptions above the holy graves.

Damasus' inscriptions were like huge billboards in the labyrinthine

darkness of the catacombs.

And it attracted huge throngs, huge crowds to the graves of the martyrs.

What was Damasus' impact on the church?

Damasus understood and saw the power radiating from the holy ashes

and holy relics, and therefore he wanted to put the stamp

of the Church on the tombs of the martyrs.

'Damasus had created a ring of holy sites around the city.

'But Christianity faced a stiffer challenge in the centre of Rome.

'Culturally, Romans were still attached to the rhythms

'and festivals of the pagan calendar,

'which promised feasting and fun.

'Christianity had to compete on a social level, too.'

By a mixture of accident and design,

the Christian calendar began to overlap with the pagan.

St Peter's birthday coincided with Caristia,

a pagan festival of banqueting and gift giving.

'By the end of the 4th century, Romans could have two parties,

'one pagan, one Christian, on fourteen days of the year.'

Some Christians even continued to participate in the shameless

immodesty of the Lupercalia fertility festival,

running half naked through the streets

while whipping girls with strips of goat hide.

'To persuade Rome's citizens to fully embrace Christianity,

'Damasus turned his gift for propaganda

'to the city's greatest spiritual asset.'

Damasus had claimed Rome for St Peter.

Now, cleverly, he claimed St Peter for Rome.

St Peter had been martyred in Rome,

and therefore, he was a Roman citizen,

and this gave his direct heirs, the Bishops of Rome, special authority.

'By commandeering St Peter's legacy for the city,

'Damasus asserted Rome's primacy in the wider church,

'and enhanced the status of Christianity at home.'

'Meanwhile, events beyond the reaches of the Empire

'were to have a devastating effect on Rome,

'changing the Holy City forever.

'By the beginning of 5th century, barbarian tribes were on the move.

'The Huns migrated into central Europe,

'displacing the Germanic Goths,

'who became refugees on the borders of the Roman Empire.'

Defenceless and hungry, the Goths were forced to trade

their own children for food, but the Romans sold them dog meat.

Tensions reached boiling point and the barbarians mobilised.

'With the Western Empire weakened by dynastic infighting,

'the Goths, under their King, Alaric, made a bold move.'

Rome was no longer the Imperial capital,

but it was the symbol of Empire.

Bewitched by its faded glories,

Alaric wanted to share in its majesty.

But what he really wanted, like every barbarian, was to be a Roman.

'Alaric besieged Rome and tried to cut a deal.

'He wanted land for the Goths to settle.

'Rome's elite, inheritors of an illustrious past,

'refused to meet the demands of impertinent barbarians.'

Alaric's response was chilling.

"The thicker the grass," he said, "the easier to scythe it down."

His dagger was at the throat of the Western Empire,

but still no compromise could be found.

'Starvation set in.

'The Romans couldn't bury their dead inside the city walls

'so putrefying bodies littered the streets.

'Desperate to put the population out of its misery,

'a noblewoman opened the city gates.

'Alaric's 40,000 Goths burst in.

'Mansions were plundered, the rich were tortured

'to give up their treasure.

'And those who couldn't flee were terrorized or killed.

'Their women, raped.'

The Goths were Arians, a sect of heretical Christians,

so they showed some restraint.

They respected the sanctity of the holy sites.

St Peter's was left unscathed,

and by the standards of barbarian sackings,

this one was less barbaric than expected.

'Nevertheless, the psychological effect

'of the sacking was shattering.

'The city that had conquered the whole world

'was believed to have been murdered.

'A sense of instability pervaded Rome.'

The great theologian of the day, St Augustine, believed the reason

Rome had fallen because it was still essentially pagan,

and steeped in sin.

The kingdom of heaven was the only salvation.

The Imperial City was doomed.

'Rome's mythological past -

'its founding fathers, Romulus and Remus - couldn't be erased.

'Paganism was still deeply ingrained.

'But one Pope who witnessed the sacking, Leo the Great,

'saw a way of channelling the prestige of the pagan world

'into the magnificence of the Christian.

'To find out how Leo shaped the Christian identity of Rome,

'I'm meeting historian Michele Renee Salzman.'

Michele, how did pope Leo promote Christianity in a city that still

had such a strong classical Roman tradition?

Leo was very proud of the

Roman tradition in the Pagan past,

he is the first Pope to

actually mention Romulus and Remus,

and to take pride in the Roman Empire in one of his sermons,

but a better empire, a stronger empire,

a greater empire resides with Christ.

So he is very involved in maintaining the physical fabric

of the city, but as a Christian centre.

So what was Leo's personal relationship with St Peter?

Leo felt very intimately connected to St Peter.

Of course, every bishop could claim that their authority

comes from Peter, the very first Bishop of Rome,

but Leo makes it a very intimate tie in his ordination sermons.

He talks about Peter's spirit almost living through him,

and I think it's very telling that when Leo is buried,

he is the first Pope buried in St Peter's,

so that tie, that intimate tie, lives on forever.

'Leo had exploited the unique link between Rome and St Peter

'to mobilize the Christian spirit of the city.

'But it was also a reminder, to the wider church,

'that Bishops of Rome were the ultimate authority in Christendom.

'And this new confidence was reflected

'in the centre of the city.'

In just over a century since the time of Constantine,

the pagan city was now infused with the spirit of St Peter.

Pristine, lavishly-decorated churches overshadowed

the temples to the old Gods.

'Rome now had the skyline of a Christian capital.

'One God, one credo, one Pope.

'But with spiritual authority concentrated in one figure,

'Rome's fate was now bound to one man.

'A good Pope could lead the Holy City to further glory.

'A bad Pope would spell disaster.

'By 536, Rome and all of Italy was controlled

'by barbarian Christian kings.

'Emperor Justinian ruled the entire Eastern Empire from Constantinople.'

He had a vision of reuniting the old Roman empire,

with himself as Christ's sacred emperor.

The jewel of Italy was, of course, the old imperial capital,

but to control Rome, Justinian needed a puppet Pope.

'So he cut a deal with Vigilius,

'the greedy papal ambassador to the East.'

Vigilius agreed to be Justinian's Pope

in return for the sum of 700 pounds of gold.

But first, Justinian had to take Italy from the Goths.

He dispatched an expedition

under his brilliant general, Count Belisarius.

In a remarkable display of military virtuosity, Belisarius,

with just a few thousand men, captured Rome.

'Justinian ousted the old Pope and installed Vigilius.

'Everything seemed to be going according to plan.'

Vigilius now regarded himself as the direct heir of St Peter.

Justinian, Christ's vice-regent on earth,

had little time for self-promoting bishops.

The two were on collision course.

Vigilius tried to assert Rome's authority.

But he was ineffectual, pleasing nobody.

Eventually, Justinian's patience snapped.

He kidnapped the Pope and sent him back to the East.

As the Pope's boat left the Tiber wharf, his reputation

was in tatters. The crowd threw stones and yelled insults.

Vigilius was even more humiliated in Constantinople.

He called a council of bishops, but it descended into a brawl.

Vigilius sought refuge in the palace church.

He clung to the altar, but was dragged out by his beard

and forced to sign a document recognising Justinian's supremacy.

'Justinian's attempt to harness Rome's holy authority

'had all but destroyed it.

'The Papacy had hit it's lowest point, and the city would follow.'

The Eastern Empire struggled to hold Italy.

Within less than a generation

another Germanic tribe had its sights on Rome.

The Lombards marched south. First plundering, then settling.

By 590, Rome was desperate and battled-scarred.

Rome's aqueducts, the embodiment of imperial might,

were left to crumble, the city's vital water supplies seeping away.

Impoverished and starving, its population reduced to 90,000,

the once-glorious capital

was now just a beleaguered outpost on the fringes of Empire.

Rome needed a new hero,

and the Pope was the only and last person who could save the city.

Cometh the hour, cometh the man.

Gregory was a super-rich aristocrat

who had already served as city prefect - in effect, Mayor of Rome.

But the messy business of politics disgusted him

and he suffered an existential crisis.

He craved a life of quiet contemplation.

'Resigning his city post, he withdrew to the family mansion

'here on the Caelian hill,

'which he converted into a monastic community.'

A church dedicated to Gregory, Gregorio Magno,

now stands on the same site.

And his spirit lives on in the custodians of the church,

the monks of the Camaldolese order.

Freed from the stresses of public office, the years spent in prayer

and reflection here were the happiest of Gregory's life.

This is said to be Gregory's monastic cell,

but there's a feature of this room that a lot of visitors miss.

That's behind this grille.

If you open it and look inside, there's just room in there

for a small man to sleep.

This is a very serene place, and it must have seemed as if

Gregory would never return to the dirty world of power and intrigue.

But Gregory's seclusion was short lived.

Rome was cut off from Constantinople by Lombard forces,

and all but abandoned by imperial officials.

In a city on the verge of collapse,

only one organization was left standing - the Church.

Reluctantly, Gregory was drawn back into civil affairs.

Ordained against his will, he ran a section of the city,

and when Pope Pelagius died of plague,

he was elected his successor.

Gregory took charge of the running of the city

and he proved to be brilliant at finance, planning and diplomacy.

He bought a truce with the Lombards and paid the wages of the military.

He donated his estates in Southern Italy and Sicily to the Church

and used them to feed the hungry Romans.

Gregory set up welfare centres across the city,

and he himself dined with 12 poor people every day.

Gregory had expanded his religious power

into the realm of political authority.

But he had set his sights much further afield.

'No pope before had seriously thought about taking Christianity

'into faraway pagan lands.'

When he was a young deacon, Gregory had seen some fair-haired

Anglo-Saxon boys at a Roman slave market.

When he was told they were Anglo-Saxon,

he said, "They're not Angles, they're Angels."

Now he was keen to expand papal powers and convert new peoples.

He dispatched a mission to England that was remarkably successful.

At Christmas 597, 10,000 Angles were baptised as Christians.

'Gregory's missionary success made Rome the Holy City of the West.

'Pilgrims from Europe's northern territories

'came in their thousands.'

The religious gold-rush was intensified by the ever-stronger

belief in the sacred power of martyrs' tombs and relics.

'Guidebooks from the period ignore Rome's classical monuments,

'directing visitors instead to Christian sites

'associated with lives of the martyrs.'

At the church of St Lorenzo, pilgrims could see the actual grill

on which St Lawrence was roasted.

At the church of St Sebastiano, they could see the arrows

that had pierced the side of the great martyr.

'Gruesome stories of the sadistic torments suffered

'by early Christians were complied and repeated,

'stories that horrified and enthralled

'Rome's new spiritual tourists.'

But there was a darker side to the pilgrim boom.

Everybody literally wanted a piece of the martyrs.

Soon there was a macabre black market in the wizened body parts

of the saints - sometimes they just snatched the entire body.

'The trafficking in body parts appalled Pope Gregory, who believed

'that contact with the supernaturally powerful bones

'brought instant death.'

But Gregory understood the value of relics.

He had special boxes made, containing filings from the chains

of St Peter, and by sending them to bishops in faraway territories,

he strengthened their loyalty to the Pope.

'Pilgrimage to the Holy City paid rich dividends for the papacy.'

'Holy travellers returned home with relics

'but also with Roman practices, which allowed Gregory to become

'the arbiter and leader of Christianity across Europe.'

'When Gregory died in 604 he was buried in St Peter's,

'where his epitaph read, "God's consul".'

He'd enriched and empowered the papacy,

combining the old with the new.

He was truly the high priest of city and church.

'The Pope now headed the most influential organisation

'in Western Europe.

'And Rome was its power base.

'The modern papacy, as we know it, was taking shape.'

But Rome now faced a completely new threat.

A new religious revelation was on the march.

Islam.

In a few decades, the Arabs had conquered a vast empire.

They captured Jerusalem,

leaving Rome the one and only Holy City of Christendom.

'Rome feared it would be next.

'The city needed an ally.

'Charlemagne, King of the Franks, was a gifted soldier-statesman

'who had conquered much of western and central Europe.

'But he aspired to the highest crown of all - Roman Emperor.

'As a devout Christian, he craved Rome's stamp of approval.

'But he didn't need to conquer Rome, Rome would come to him.'

On 25th April 799, Pope Leo III was near here,

on his way to the Church of San Lorenzo in Lucina,

when he was ambushed by armed retainers of the previous Pope.

They tried to gouge out his eyes and slice off his tongue.

Pope Leo needed Charlemagne's protection from his rivals,

and from the threat of Arab and Lombard invasion.

'And Leo could offer Charlemagne

'the one thing he didn't already have.'

There was a story, told in this fresco,

that Pope Sylvester had healed Constantine the Great of leprosy.

Sylvester's reward was Constantine's conversion to Christianity.

But that wasn't the only thing

that Constantine was said to have given the Pope.

Pope Sylvester is in firm control.

He's sitting on his throne and there's the Emperor Constantine,

kneeling and compliantly surrendering his crown

to the dominant Pope.

This account was a complete fabrication,

but it allowed Leo to invent a new tradition.

The power of Popes to anoint Emperors.

On Christmas day 800,

Charlemagne arrived to celebrate mass in St Peter's.

He knelt down before the tomb.

As he bent down, the Pope placed a crown on his head

and anointed him Holy Roman Emperor.

The new imperial alliance seemed to increase papal authority

and protect Rome.

But actually, it was flawed from the start.

The Popes believed that they were the ultimate source of political

and religious authority, so only a Pope could crown an Emperor.

But the Emperors believed that they were the supreme power,

so an Emperor could appoint the Pope whose job it was to crown him.

'The deal didn't live up to its promise.'

In 846, Arab forces attacked the city.

For the first time, St Peter's Basilica,

the essence of Rome's sanctity, was wrecked and looted.

When the raiders had gone,

Pope Leo IV put his faith in something more solid.

It's easy to forget that St Peter's was still outside the city walls,

and therefore vulnerable to attack.

Now Pope Leo embarked on building these massive fortifications.

The Leonine Walls were 40 feet high and 12 feet deep,

and they forever changed the shape of Rome.

The source of Rome's divine power was now not just sanctified,

but fortified.

Rome's holiness was protected.

Only for it to be poisoned from the inside.

As the political power of the Popes had grown,

their position became highly sought-after.

The papacy became the prize and plaything in the blood-splattered

power struggle between competing Italian families.

Several popes were murdered here at the Castel St Angelo.

Once the mausoleum of the Emperor Hadrian, and now the fortress,

prison and torture chamber of the papacy.

'The Popes became power-hungry players

'in the savage scheming of Italian politics.'

'And their abuse of papal authority dragged the Holy City

'into its darkest period yet.

'In 897, Pope Stephen VI gave an order

'of the most twisted and malicious kind.'

'He ordered the digging up of the corpse of a former Pope

'whom he hated.'

Pope Formosus' mummified body was dressed up in papal robes,

propped up on a mock throne and put on trial before the Holy Synod.

His crime, violation of canon law.

'The charges were read out,

'and a deacon assigned to defend the accused Pope.'

Found guilty as charged, Formosus was stripped and mutilated.

The three fingers he'd used for papal blessings were chopped off.

'He was dragged and tossed into the Tiber.'

But this grisly masquerade was only the start.

From now on, nothing was sacred.

The Popes played a vicious game of power and pleasure.

No crime was too diabolical for these heirs of St Peter.

'In the early tenth century, the papacy became dominated

'by one aristocratic family,

'the debauched and merciless house of Theophylact.

'The scurrilous chronicler of their rise to power

'was bishop Liudprand of Cremona.'

Liudprand doesn't exactly hold back,

especially with the women of the family,

who are described, without exception,

as a tribe of sex-mad megalomaniacs.

He says Count Theophylact's wife Theodora was a "shameless harlot",

and that her two daughters were, if anything,

"faster in the exercise of Venus".

The most infamous was Marozia.

A wily politician and murderous man-eater, Marozia must have been

as gorgeously depraved as she was dynastically effective.

She seduced or married an entire apostolic succession

of popes and kings, and managed to dominate Rome for years.

'Drawn deeper into the mire, Rome's once-mighty Popes

'became pawns in the cesspit of local politics.'

'At just 15, Marozia had a "wicked affair" with Pope Sergius III,

'producing a son.'

'Later, Marozia became mistress of another Pope, John X,

'but she turned against him and married his enemy, Guy of Tuscany.'

In 928, they successfully carried out a coup d'etat

in the Lateran palace, the papal residence.

Marozia had John X arrested, imprisoned and then strangled

in the Castel St Angelo, leaving her as de facto ruler of the city.

'The papacy and Rome sank to ever greater depths of moral depravity.

'Marozia even raised her own bastard son to the throne of St Peter.'

But things began to fall apart for Marozia.

Her other son, Alberic, invaded Rome, arrested John XI

and imprisoned his mother in the Castel St Angelo.

Marozia died in there, probably murdered by her own son.

As for Alberic, he ruled Rome for 20 years with the majestic title

Prince and Senator of all the Romans.

'The Holy City was on its knees.

'The Emperors, once Rome's protectors,

'were now in the ascendant, dominating Italy.'

The Holy Roman Emperors, successors of Charlemagne and, in effect,

Kings of Germany,

repeatedly marched south to attack Rome and terrorise its Popes.

'Only a few Popes had the strength to fight back by reinvigorating

'papal authority and the sanctity of the city.'

In 1075, Pope Gregory VII took a stand.

He published the Dicatatus Papae,

that declared the absolute supremacy of the papacy and Rome.

From now on, Emperors would bow to Popes.

Gregory's posturing infuriated the German Emperor, Henry IV.

He deposed the Pope.

But Gregory hit back, ex-communicating Henry -

in effect, stripping him of all his powers.

The toxic relationship between Pope and Emperor had ignited,

and Rome was its victim.

Gregory allied himself with the Normans,

but when they occupied the city in 1084, things turned violent.

Rome became a blazing inferno.

A thousand years earlier, a pagan emperor had burnt Christians alive

and crucified St Peter.

But their martyrdom had helped keep

the flame of Christianity alive in Rome.

Constantine had taken an underground religion

and staked all of Rome's glory on its success.

Now the ambitions of a Pope had brought ruin on the Holy City.

'The Popes were to abandon Rome altogether,

'and seek the protection of the Kings of France.'

It seemed like the end.

After 2000 years as head of the world,

the capital of Emperors and Popes,

the very definition of sacred power,

the city blessed by God was now cursed by invasion,

intrigue and depravity.

Its sanctity, debased.

Holy no more, time had run out for the Eternal City.

'Next time, Rome rises from the ashes.'

'How the debauchery and avarice of the Renaissance

'transformed Rome into the city we see today.'

Subtitles by Red Bee Media