♪♪ ♪♪ -It is the world's most famous cathedral.

Majestic and inspiring, this marvel of Gothic architecture seemed to defy time.

But in 2019, the world would discover just how fragile she was.

[ Thuds loudly ] -One of the things we learned on the 15th of April was how much Notre Dame means to people all over the world.

-When construction began in the 12th century, people didn't use cranes or drills, not even wheelbarrows.

Notre Dame is a pinnacle of human achievement.

-We must put ourselves in the shoes of people from the Middle Ages.

It was far too ambitious.

-These medieval builders were pushing the boundaries of what was possible.

♪♪ -They were working at the cutting edge of technology.

-Flying buttresses, 50 feet long.

Huge rose windows, the largest at the time.

-They are the most complex aspect of architecture.

-It is a reinvention of stone architecture.

-Spanning eight centuries, the history of Notre Dame includes repairs, restoration, and expansion.

-If we'd let things be, the cathedral would not be standing.

-Victor Hugo made the cathedral a part of the popular imagination.

Eugène Viollet-le-Duc's 19th-century renovations improved on the original Gothic architecture.

-Viollet-le-Duc's obsession is to uncover the building's logic, like an archeologist.

-Now, historians, engineers, and archaeologists have undertaken a comprehensive study of the great church.

-What problems did masons, stonecutters, and quarrymen face?

We follow the same path as the builders.

-The hope is to understand how Notre Dame became the queen of cathedrals.

-The building sites of the Middle Ages were like Silicon Valley in California today.

That was where everything new was discovered.

All the innovations that were so important.

♪♪ -"Building Notre Dame."

♪♪ -In the middle of the 12th century, Paris is not yet a capital city.

Despite its dynamic economy, it has just 40,000 citizens.

And its cathedral is a modest one -- St. Etienne on the île de la Cité.

-Paris has to do something.

They cannot leave the old buildings as they were.

They must think about making themselves visible.

-One man believes a new cathedral will be key in making Paris an important city.

In 1160, Maurice de Sully is elected Bishop of Paris and oversees the diocese from St. Etienne.

-Maurice de Sully is the Bishop of Paris between 1160 and 1196, a very long bishopric of 36 years.

Reconstructing the cathedral is his initiative.

He is the key figure who harnessed the energy for this unprecedented construction project.

-[ Concludes in French ] -De Sully is from a modest background, but is clearly a man of great ambition, and as bishop, he also has the power to accomplish his plans.

-If you think about these things as political gestures, as gestures of assertion and identity, we understand the scale of this building much better.

-One can imagine de Sully's ambition rising like Notre Dame's vaulted ceiling, more than 100 feet in the air.

-[ Speaking French ] -It is hard to appreciate these proportions, because inside everything feels harmonious and logical.

But the building is absolutely enormous.

It is 130 meters long.

The nave is as wide as a bus.

And vertically, you can fit an airliner in the nave.

-[ Speaking foreign language ] -The blessing of Notre Dame's first stone takes place in the spring of 1163 in the presence of both Pope Alexander III and French King Louis VII, two of Europe's most powerful men.

-Maurice de Sully seems to be working closely with Louis VII.

He involves the king in the great event of the laying of the first stone, with the Pope as well.

It's a kind of meeting of church and state.

♪♪ -We place our church under the protection of the Virgin Mary, the mother of Christ.

It will be called be Notre Dame Cathedral... Notre Dame de Paris.

-Changing traditions in the Catholic Church inspire the cathedral's new name -- Our Lady.

Veneration of the Virgin Mary is flourishing at the time.

In the 12th century, the mother of Christ becomes a central figure in the liturgy, especially in Paris.

-She is the mother.

The Virgin Mary has a role of being accessible, understanding, and also being an intercessor.

This is so important.

Imagine, of course, that medicine is practically unknown except for herbal practices, etcetera.

So the sympathetic intercession of the Virgin seems especially important.

♪♪ -In the Middle Ages, life revolves around religious duties and practices.

Some part of the original St. Etienne church needs to remain open during the construction of Notre Dame so that nine daily masses can still be offered.

Everything about the new building is designed for the purpose of worshipping God.

The main areas of the church -- the sanctuary and altar, transept and nave -- form the shape of a cross with the sanctuary symbolizing the head of Christ.

It faces east to welcome the first rays of the sun.

[ Birds chirping ] Before the foundation can be laid, the builders must first dig out the soil of île de la Cité, the island in the middle of the Seine.

-The goal is to prevent the building from sinking.

So they dig until they hit very compact soil, presumably until they reach the Seine's former alluvial deposits, 9 meters below today's sidewalk.

Most probably, they dug out the height of a house, with a ground floor and two stories -- a truly colossal undertaking with pickaxes and buckets.

♪♪ -The trenches are then filled with hundreds of tons of roughly cut stone blocks to strengthen the foundations and support the cathedral's colossal weight.

But Notre Dame is just one of many churches built during this period.

-The first thing to understand about the age of the cathedrals is that from about 1000 to 1300, it was warmer than usual.

Just as we have ice ages, we also have warm ages.

And when there's a warm age, there are more crops, people get richer, and they have some spare money.

So one of the reasons the cathedrals were built was that Europeans had more money than previously.

♪♪ -An architectural revolution is underway in France.

In the 1140s, a portion of the Saint-Denis Abbey located north of Paris is rebuilt.

Walls are replaced with large bays of windows.

♪♪ -[ Speaking French ] -The light is tinted by the stained glass, which depicts religious scenes and characters.

This gave people a sense of the higher reality of the hereafter, of paradise and God.

-We should see this architecture as spacious and full of light.

No one had seen anything like it.

-Maurice de Sully is obviously very aware of what is going on around him.

-And Maurice de Sully's project takes advantage of these innovations.

Notre Dame unites all the characteristics of Gothic architecture in a single building for the first time.

The shape of the Gothic arch makes it possible to build taller buildings.

And the ribbed vaults in the ceiling distribute the weight of the roof onto pillars, allowing the walls to be opened up with windows.

Outside the church walls, the flying buttresses -- the largest of their time -- absorb the horizontal thrust.

-[ Speaking French ] -Notre Dame includes elements developed on earlier projects, but surpasses them all through its enormous scale.

-[ Continues in French ] -To keep such a slender structure in balance, certain techniques had to be perfect, such as the extraordinary use of flying buttresses measuring 15 meters long.

The daring nature of this architecture is still appreciable today.

♪♪ -It must have seemed like an impossible task to the builders of the Middle Ages.

But Notre Dame's location gives it an advantage in one important area -- transporting materials would have been far too expensive.

Fortunately, the site is near several limestone quarries.

-The stone is excellent.

It's underneath your feet.

So Gothic really had to happen here.

-The abundance of limestone means it can be used in many different ways.

-île-de-France has a thick layer of accessible limestone, but depending on the depth, you find limestone with different mechanical properties.

-[ Continues in French ] -One location provides limestone for columns, which are massive and bear heavy loads, and another for delicate sculptures.

♪♪ -The limestone quarries are located along the banks of Paris's rivers.

♪♪ -And limestone isn't the only important material needed at the construction site.

Wood is just as crucial.

-The most important material is firstly wood.

For the framework, for the form work... ...wood for scaffoldings... wood for carts... and tools.

Wood is everywhere.

♪♪ -There is a unique site in Burgundy where we can see how medieval builders relied on wood.

Here, a 12th-century chateau is being rebuilt using only methods from the time period.

-When the group began their work 20 years ago, they knew large quantities of wood would be needed -- first for the scaffolding.

Initially, the scaffolding was built on stands.

But above a certain height, medieval builders developed an ingenious system to hang these supporting frames from the wall.

-[ Speaking French ] -During medieval times, scaffolding was mostly hung from walls using putlogs, a piece of wood that sticks into the wall and serves as a ledge to hold up planks.

-[ Continues in French ] -This installation set the pace for each successive stage of wall construction.

-The holes used to attach beams in the 12th century are still visible on the walls of Notre Dame today.

The need to lift the heavy limestone blocks up several stories, without the use of a modern crane, leads to another innovation.

Using an illustration from a 14th-century Bible, the Burgundy team has built a machine that would have enabled medieval builders to lift heavy loads... ...a dual treadwheel crane, operated by two people.

♪♪ -[ Speaking French ] -This squirrel cage built on a swivel has a jib arm with a payload of 500 kilos, which means each lift can place up to half a ton of stone on the walls, up to a height of 18 meters.

-[ Continues in French ] -10 lifts per day adds 5 tons of material to the walls.

This raw data for the average building rates was generated by our experiment.

-And limestone isn't the only material that must be brought up to the builders.

Vast quantities of mortar must also be lifted to the tops of the walls and scaffolding.

The mortar binds each of the blocks to create walls, and when mixed with gravel, fills the interior to provide greater strength and stability, which has helped the cathedral stand for more than 800 years.

♪♪ The mortar mixers of Burgundy have developed their own method.

Mortar is a delicate blend of sand, water, and lime.

It is indispensable for construction, but fickle to work with.

-Our experiment has shown that you can use these mortars in all weather.

We do not work in freezing conditions because the lime mortar loses its mechanical resistance.

It's very difficult to work during dry periods and heat waves, when we have to cover the masonry and add water to the mortar.

So medieval construction, insofar as our experiment helps us grasp it, entails almost daily adaptation to climate and weather.

-After more than 15 years of construction, the builders have completed the altar and its sanctuary.

It is three stories high, and measures 100 feet tall.

And the construction crew was smaller than one might imagine -- only a few dozen people at a given time.

-This varied over time, and according to the season.

The building site was not isolated, as there are people working in quarries and forests as well.

-[ Continues in French ] -It is surrounded by an entire industrial system that makes this construction process possible.

-[ Concludes in French ] -[ Grunts ] -[ Shouting in French ] [ Indistinct conversations ] ♪♪ -Building Notre Dame is an organizational challenge unlike any other.

To ensure the construction runs smoothly, de Sully and the other church leaders work together as what we would think of as a project management team today.

Managing the budget and hiring technical experts are things this group would handle.

♪♪ [ Box thuds softly ] Most importantly, the team hires the master builder, the equivalent of an architect.

Without written records for Notre Dame, the best way to understand the role of the master builder is to look at a master builder's contract for another nearby cathedral.

-[ Speaking French ] -Contracts stipulate that the master builder must be loyal to the contracting authority.

-Your Grace.

-That he cannot accept work elsewhere, or leave with the plans.

If he's sick, he will not be paid.

During the Middle Ages, people are paid in sols, in sous, and in tournois pounds, but also received a great deal of their pay in kind -- housing, firewood, and clothing.

[ Grunting ] -The identity of Notre Dame's master builder is unknown.

It is the craftsmen at the construction site who lead the Gothic revolution, not academics.

-The innovations of Gothic construction were not made by intellectuals, they were not made in universities.

They were made by men who worked with their hands.

-The master builder of a medieval building site in the 12th and 13th centuries is firstly an incredible artisan.

An artisan with experience in the cost of materials and know-how... [ Hammering ] ...in transmission, and knowing how to lead people.

He's an entrepreneur who inspires his team.

-With all of the different industries and tradesmen involved, a precise organizational structure with clear rules is the only way they can all work together successfully.

-Each trade has a master leader who usually possesses expensive tools.

♪♪ -For younger workers, training lasts for several years, during which they are paid.

These groups were the predecessors of today's unions and apprentice programs.

-You have a multigenerational situation where young people are learning from old people who have experience.

And new ideas are introduced.

The way of building is modified as time goes on, and you -- It must have been an extraordinarily exciting environment to be in.

-One difficult question to answer is how much the construction of Notre Dame cost.

Any price tag would have to include materials, much of which was likely the property of the Catholic Church.

And labor was often paid at least partially in kind with room and board.

When compared with other buildings of the time, historians have suggested the cathedral cost roughly 150,000 pounds, though it is hard to convert that to an amount in today's dollars.

For the sake of comparison, de Sully, one of the richest men in Paris, donated 100 pounds to the project.

-[ Speaking French ] -100 pounds compared to a total cost of 150,000 pounds or more.

Occasional financing, such as the donations from major figures we find in the archives, was not enough to finance construction.

-[ Woman vocalizing ] -The diocese could rely on income from its land in the Paris Basin.

-The diocese of Paris, which corresponds to the heart of today's île de France, is an incredibly rich area.

It also has substantial real estate holdings in Paris.

Until the early 13th century, the bishop claimed ownership over the land between the Rue Saint-Denis and the hill at Chaillot.

This includes practically one-quarter of today's Paris, and it came with royalties providing considerable financial revenue.

-But not of all of the income derived from church real estate holdings would be spent on Notre Dame.

-May God be with you.

-De Sully develops other methods to finance his grand project.

-God bless you.

-Thank you, Father.

-[ Speaking French ] -Maurice de Sully is not against using stratagems to raise more funds.

-[ Continues in French ] -He issues indulgences, documents that granted sinners remission from punishment in exchange for payment.

Rather than making a pilgrimage to Rome or Santiago de Compostela, the sinner simply paid a sum.

-[ Concludes in French ] -Lord, forgive me... -The bishop is willing to issue indulgences to people who've committed a range of sins.

His priority is financing his cathedral.

-On the one hand, you have an ambitious bishop who understands the representational role of the cathedral.

On the other hand, you have people who say, "But Christ was poor.

Blessed are the poor.

We should give away what we have."

So you always had this tension within the church between expenditure on delightful buildings and charity and generosity.

And this is a complicated issue.

♪♪ -While some people may frown on de Sully's methods, the donations are a way to involve the community in the church's construction.

-If the cathedral sparks such fascination among the people, it's because they can relate to it.

This doesn't mean they took part in construction, but they helped finance it.

I believe this contributes to the greatness of these buildings.

-Five years after its construction is completed, the altar is consecrated in 1182 and is available for church services.

-[ Speaking French ] -A temporary partition of timber or plaster was probably used to insulate the choir so that religious life can continue, while building continues in the transept and nave.

♪♪ -The King!

-The second phase of construction begins during the reign of Philippe Auguste, with whom de Sully had a close relationship.

-Your Grace.

-Philippe.

-How is your cathedral coming along?

-More importantly, the king makes Paris his capital.

And the fate of Notre Dame changes dramatically as a result.

Determined to improve the city's standing, Philippe Auguste begins construction on a fortified city wall as well as the Château du Louvre.

During his reign, France becomes the leading European power, and the population of Paris expands.

-Therefore, there is a self-consciousness of Paris.

The walls are important in that.

The cathedral is important in that.

The Royal Palace, the abbey of the temple, where they are keeping the financial records -- all these institutional settings in the city collaborate, right, in the creation of the idea, "This is the center."

And that happened then, and it's still the case now.

♪♪ -As Paris prospers under Philippe Auguste, the builders accomplish one of their most difficult tasks -- the vaulted stone arches that make up the ceiling.

-This is one of the mysteries of cathedral construction, because it's probably the most complex process -- firstly, because they are very high, so you have to work at a height.

And because they take the shape of a formwork that has not survived.

-Wooden rafters sit on stone pillars.

Then, stone blocks are placed on top of the rafters to form the vault's ribs.

Once the arches are in place, their blocks are cut to fit and lock with the keystone.

Lastly, more stone blocks fill in and enclose the vaults.

-The revolutionary ceiling is a stunning achievement, and construction continues on.

The transept is completed in the 1190s.

♪♪ Maurice de Sully, who launched this grand project and oversaw it for 30 years, dies in 1196.

-[ Speaking French ] -I don't think anyone who saw the start of construction imagined that they would see the end.

♪♪ -The next major task for the builders is to raise the western facade, with its magnificent portal entrances.

-[ Speaking German ] -The portals connect the inside and outside of the cathedral.

They symbolize the transition from earthly life to the hereafter, to heavenly life.

-[ Continues in German ] -That is the purpose of the Church -- to connect heaven and earth.

-[ Concludes in German ] -[ Speaking French ] -These great series of portals are sometimes called "stone bibles," with subjects relating to Christ, the Virgin Mary, and saints.

This dates back to Pope Gregory the Great in the late 6th century, who promoted figurative decoration for an illiterate public that did not have access to the Gospels or the Bible.

-[ Concludes in French ] ♪♪ -[ Speaking German ] -Designing the portals required close cooperation between intellectuals, namely clergymen and artists, since clergymen established the sculptural plans to be produced for the portal.

-[ Continues in German ] -This probably took the form of discussions such as, "No, let's move the Christ a little higher.

It will be more in harmony with the Virgin Mary."

Something along those lines.

-Hundreds of statues decorate the lower half of the immense wall.

♪♪ In the 13th century, Parisian sculpture becomes more refined, with more delicate drapery and increasingly lively expressions.

The Gallery of Kings, 28 statues that sit above the portals, have an unprecedented level of detail.

Each statue is nearly 10 feet tall and stands 40 feet off the ground.

And they suggest a greater understanding of perspective, well before its formal theorization in the Renaissance.

Both the bodies and the heads of the kings are larger than possible in nature, but when seen from the ground, they appear normal.

-I wouldn't call it perspective in the technical sense, but certainly an empirical understanding of the appearance of things as seen from a certain angle.

-[ Speaking French ] -The statues of kings in the gallery are at a height of 12 meters.

The faithful visiting during the Middle Ages had little room to step back.

The church square was incredibly shallow, just 35 meters deep.

So one could only observe the statues standing very close to the portals.

♪♪ -The statues of kings that decorate the cathedral today were designed by Eugène Viollet-le-Duc in the 19th century.

But an analysis of the remains of the original 13th-century statues has revealed something surprising.

-[ Speaking German ] -We had already analyzed the west facade, and found color everywhere.

This means the cathedral must have been multicolored.

We noticed that there were multiple layers of color.

This means that it was not painted just one time, but constantly repainted, and certainly in a different way.

♪♪ -During the Middle Ages, Notre Dame's facades were covered with colorful paint and even gold.

-It is proven, these colors were very bright -- bright red, bright yellow, bright green.

Quite shocking to our eyes, which are much more accustomed to a very monochromatic appearance.

♪♪ -I think if we could go back in a time machine and see Notre Dame in, let's say the 13th century, we might have said, "Oh, too bright!"

[ Laughs ] ♪♪ -The disappearance of the bright colors is a reminder of all the cathedral has witnessed in her eight centuries.

♪♪ -[ Speaking French ] -Cathedral construction is subject to many unforeseen events -- work stops during extremely cold weather, frost threatens the masonry before the mortar dries.

♪♪ The Seine regularly bursts its banks, potentially paralyzing the surrounding area.

-The church has survived all kinds of disasters, from floods to political violence.

♪♪ -Cathedrals are built as a kind of triumph over adversity.

-After 60 years, as they near what they believe is the end of construction, the builders realize their work of art has a significant flaw that might endanger its future.

-There were no gutters, no system for collecting rainwater.

-Water has always been the great enemy of architects.

-Water running down the exterior walls of the cathedral seeps into and erodes the stone and causes cracks when frozen.

For a building the size of Notre Dame, the problem of water removal is on an extreme scale.

An average downpour means nearly 7,000 gallons of water must be drained away.

-[ Speaking French ] -Notre Dame's architects had the brilliant idea of using the tops of the flying buttresses as gutters.

[ Thunder rumbles ] -As the flying buttresses are hollowed out, they are then connected, forming a large network for water collection.

Throughout the system, water shoots out of the gargoyle statues' mouths, away from the church walls.

♪♪ This effective drainage system, restored by Viollet-le-Duc and maintained since, is still at work today.

[ Thunder rumbling, crashing ] ♪♪ Engineering this water removal system in the Middle Ages brings spectacular changes to the cathedral.

The builders dismantle the roof and raise the church walls by six and a half feet.

They transform the small terrace roofs and rework the flying buttresses.

The structure supporting the roof is entirely remounted -- 1,200 tons of wood and lead.

And the builders take the opportunity to crown Notre Dame with a spire.

During this new phase, the windows are expanded and extended, a technical exploit that puts the building far ahead of other cathedrals under construction.

-This is one very obvious way in which the builders of Notre Dame modernized during the process.

-They kept changing their minds.

They had no sense that they were working in an old tradition.

They were working at the cutting edge of technology.

♪♪ -In the late 1230s, the builders erect the two towers that anchor the western facade.

At the base of the towers, Andrew Tallon and Dany Sandron discovered evidence of a near-catastrophe.

-[ Speaking French ] -We realized that once the first level of Notre Dame's western facade was built, with the portals and their thousands of tons of assembled stone, it tilted forward a little.

-[ Concludes in French ] [ Beeping ] -This outward tilting is visible to the naked eye from the surrounding area.

The weight of the wall, with its heavily decorated portals and massive towers, has caused the ground beneath to shift.

-[ Speaking French ] -What can be done?

Not much, other than wait and see how it behaves over time.

-[ Speaking French ] -We can imagine the dread of the architect and his collaborators, wondering whether they could continue building.

-Probably the ground will compress and the facade will stop moving, and they can start building the upper sections.

-So the upper levels are straightened... [ Beeping ] ...and by chance, the ground had indeed stabilized.

♪♪ -One can only imagine how medieval Parisians viewed their new cathedral as it neared completion.

♪♪ -We should put ourselves in the shoes of people from the Middle Ages, who would catch sight of the cathedral in the urban landscape, lose sight of it in the city, then come upon the enormous facade at a distance of a few dozen meters, in this incredibly reduced church square.

-[ Inhales sharply ] ♪♪ -But a cathedral is not only something we see, but we hear.

[ Bell rings, distant shouting ] -The western facade towers housed heavy bronze bells, which in medieval times weighed more than 1,000 pounds.

Over the centuries, more bells were added, including one weighing 13 tons.

It would have been difficult for the limestone walls to withstand the weight of the bells.

Instead, the builders constructed a wooden belfry inside the towers, from which to hang the bells.

-When the bells swing, this flexible wooden framework absorbs the strain, protecting the upper sections of the towers from exposure to vibration and deterioration.

[ Bells ringing loudly ] -In the Middle Ages, the church's bells kept time and marked the rhythms of daily life in Paris.

[ Ringing continues ] They rang when it was time to wake up, and when work was finished.

And they warned of dangers and tolled during celebrations.

[ Ringing continues ] -[ Speaking French ] -Some examples are astonishing.

For instance, to mark the birth of the heir to the French throne, the bells could ring uninterrupted for three days and three nights.

That means you can't sleep in Paris during that period.

People celebrated, of course.

♪♪ -By the 1240s, the cathedral has the general form that remains today.

But construction continues on.

The builders enlarge the transept and transform two of its walls with gigantic rose windows more than 40 feet across.

Architecturally, this marks the beginning of a new era.

-[ Speaking German ] -The transept's rose windows are the most complex aspect of architecture.

-Who was the architect?

The base of the south transept's wall reveals the identity of the man responsible for the design of both the northern and southern facades.

-"The year 1257 of our Lord, 12th February.

This was begun in honor of the mother of Christ by Master Jean de Chelles, a mason in his lifetime."

-Based on this inscription, historians have long attributed the northern facade and the beginning of the southern facade to Jean de Chelles.

-There is no source or description.

All we know about the facades of Paris comes from the facades themselves.

[ Beeping ] -Albrecht's team recently scanned and analyzed the transept facades.

♪♪ -[ Speaking German ] -After much work, we identified the exact plans of the facades.

We wondered what could be deduced from them.

We superposed the two plans, and surprisingly discovered they were exactly identical.

-[ Concludes in German ] -Identical facades indicate they were built using the same plan, and confirms Jean de Chelles was responsible.

♪♪ -[ Speaking German ] -If we analyze the transept, the two facades must clearly date from the same period, meaning two different workshops worked simultaneously.

-Two workshops working at the same time from the same plan.

In the mid-13th century, the organization of the building site has become more elaborate, and its productions increasingly advanced.

-Within Notre Dame itself, we can witness a profound transition.

We're getting into a level of conscious design, and that has to do with using stone in this new way.

Using stone so that it's no longer laid horizontally, but rather can become a membrane, like a spider's web.

We're in a very evolved profession, one that is much more concerned with geometry, and the use of certain kinds of tools, for example the compass, to generate design ideas.

-The term "architect" is not used in the 13th century, but this new generation of master builders is making advances.

They now rely on more sophisticated methods and tools.

The complexity of this rose window, with its thin veining measuring just 20 centimeters in diameter, is obvious.

Each petal is identical, repeating the same design elements.

The petals are held in place by the tracery, the stonework that outlines the glass panes.

In turn, the stones of the tracery are held together with metal pieces.

The 80 glass medallions are contained in iron hoops.

♪♪ Like the metalsmiths, glaziers also get to work.

Each rose contains nearly 600 square feet of glass.

♪♪ Glassworks produce disks of colored glass that are then cut in the workshop and assembled on drawings of the same scale.

♪♪ The glass that makes up scenic elements is outlined with gray paint, which produces a multi-dimensional effect.

These panes seem fragile, but those in the north rose window have resisted wind, extreme temperatures, and even the fire of 2019.

This area of the cathedral is finished around 1270.

-Imagine the peasants coming in for the service.

They're going to think it's a miracle that something could be built this big and this beautiful.

♪♪ -In the late 13th century, chapels are built up to the buttresses.

♪♪ After more than a century, general construction comes to an end... ♪♪ ...although the cathedral continues to be embellished.

♪♪ These stone panels are added to enclose the sanctuary.

And then, as the 13th century closes, Gothic architecture falls out of favor, marking the beginning of a long break in work on the cathedral.

♪♪ Notre Dame weathers the next several centuries, but falls into disrepair and is even vandalized during the Revolution of 1789.

But by the early 19th century, the church is taking on a more significant role in civic life.

-People go there because it's large, it can host crowds, and it's suited to political communication, including for the king.

[ Somber organ music playing ] -In 1804, Napoleon holds his coronation there.

♪♪ -Napoleon creates a new dynasty, and with it a new sanctuary, one that is conveniently urban, civic, and popular.

♪♪ [ Bell tolls ] -When Napoleon falls in 1815, the church returns to the shadows.

But a popular novel changes Notre Dame's place in history.

Victor Hugo's "The Hunchback of Notre Dame" is published in 1831.

♪♪ -It's really Victor Hugo who makes it a personality, makes it a character.

I mean, it is a central figure in his novel, and it is an image of a huge, brooding, mysterious, complicated structure.

-The book transports 19th-century Parisians back to the Paris of the Middle Ages, alongside the beautiful Esmeralda and the hunchback Quasimodo.

-It is a Paris of crowds, of the rabble, common people, small merchants, little shops.

It's a legendary Middle Ages that combines a bit of everything, a romantic Middle Ages.

-The novel is a huge bestseller, and it transforms how Parisians view their cathedral.

-It is odd that it took a novel for people to suddenly appreciate the value of something that had been before their eyes for 700 years.

If Victor Hugo hadn't sounded the alarm for the cathedral, if we had let things be, the cathedral would not be standing.

♪♪ -The general and prevailing taste is not in favor of the Middle Ages.

People like simple and spare forms, with Euclidian volumes.

-But a shift in how Parisians feel about Gothic architecture is underway.

-Victor Hugo says, "This classical architecture, it's not our architecture.

It's Greek and Roman.

What's French architecture, what's national architecture, is Gothic.

It is Notre-Dame de Paris."

-Gothic architecture -- with Notre Dame as its beacon -- becomes synonymous with the idea of a national French identity and its culture.

For the country's leaders, using culture is a way for them to establish legitimacy.

-This is a very 19th-century dynamic -- after the revolutionary abyss and the imperial experience, to combine and balance elites and the people.

-[ Continues in French ] -Notre Dame is clearly among those sites that are both popular and prestigious.

-So there is every reason to launch a media campaign in favor of Notre Dame's restoration.

-By 1844, another major restoration is underway, led by Jean-Baptiste Lassus and Eugène Viollet-le-Duc.

While Lassus has many years of experience, it is Viollet-le-Duc who has the creative brilliance.

And when Lassus passes away in 1857, Viollet-le-Duc's genius shines.

The challenge is to decide what spirit or sensibility should guide the restoration.

-It was an entirely new discipline at the time.

Until the time of Viollet-le-Duc, monuments were repaired, not restored.

-[ Continues in French ] -So when a chapel was needed, it was built in the style of the period.

That's why we have cathedrals with 14th-century chapels, 18th-century sacristies, and elements from the Renaissance.

This produced a, shall we say, heterogeneous monument.

♪♪ -Viollet-le-Duc's team starts small.

-[ Speaking French ] -The two architects were initially very prudent.

They did not want to make careless restorations.

They proposed making as few as possible.

-Good.

-In the first phase of the project, the architects reinforce the fragile sections, and reconstruct the flying buttresses, one after another.

♪♪ -Viollet-le-Duc's obsession is, like an archeologist, to find the building's logic in the stones and their shapes.

-The restoration provides an opportunity to study the building from top to bottom.

It is Viollet-le-Duc who discovers most of what we know about the cathedral today.

The remains of one of the small rose windows lead Viollet-le-Duc to determine what the nave's upper windows looked like originally.

♪♪ He sees that the upper windows' columns did not extend all the way down when the church was first built.

Instead, the columns were capped with small rose windows known as oculi, whose remains he had found.

It does not matter to Viollet-le-Duc that this change was made in the early 13th century to allow more light into the cathedral.

He wants to restore the church to its original 12th-century state.

-His passion for Notre Dame is all the greater, since it's a laboratory for understanding the principles of Gothic art, and bringing them to light, to the public.

-[ Concludes in French ] -He reworked the vaults.

He redid the facing.

He reinstalled a water drainage system, so the flying buttresses with their gargoyles.

He added decorations that may seem superfluous, such as crockets, finials, pinnacles, and so on.

♪♪ -Viollet-le-Duc rebuilds the original windows for the transept.

He has the chapels painted, new railings cast for the altar, and also builds a sacristy.

He rethinks every detail of the decoration and furniture.

The church is now his manifesto of Neo-Gothic architecture.

-He even made objects for worship, such as wafer boxes and chalices.

So he started with the structure and ended with doorknobs.

That's the work of Viollet-le-Duc.

-To reinforce the south rose window, which is in danger of collapsing, Viollet-le-Duc rotates it by one half petal.

-So in the popular imagination, it's Viollet-le-Duc that counts as much, or maybe even more than the actual medieval building.

♪♪ -The architect covers the cathedral with a profusion of fantastical decorations that have shaped the cathedral's image -- the Disney cartoon and other fantasies.

♪♪ ♪♪ -Notre Dame's medieval spire was taken down in the late 18th century.

Rare drawings from the time show its modest shape.

But Viollet-le-Duc imagines a new spire.

It is twice the size of the first one.

The architect wants to make Notre Dame the tallest monument in Paris.

-This is why he's depicted in a caricature with a giant head and small body, a small, ridiculous cathedral in his hand with a never-ending spire.

♪♪ -Metal is the obvious choice of material for the spire.

But Viollet-le-Duc has something else in mind -- Wood, just as in the Middle Ages.

The builders have a complex system for representing three-dimensional objects in two dimensions.

A flattened full-scale template is drawn and laid out on the floor of the carpenter's workshop.

Then, they cut the beams the same size as dictated by the template.

♪♪ This technical exploit is completed in 1859, rising 300 feet and surpassing the largest monuments of Paris.

♪♪ And as Baron Haussmann transforms Paris into the modern city we know today... Notre Dame becomes a permanent part of the landscape.

♪♪ -Paris becomes modernized and "de-medievalized," because most of the medieval buildings that were still standing disappeared at this time.

The entire neighborhood surrounding the square disappears to make room for the large esplanade that heightens its perspective and monumentality.

-[ Concludes in French ] -Notre Dame now takes center stage before a large square.

The cathedral is a mixture of medieval architecture and Viollet-le-Duc's interpretation of medieval architecture.

-The 12th and 13th century cathedral is still there.

It's absolutely everywhere.

We must stop thinking that Viollet-le-Duc was a somewhat crazy medieval poet.

Not at all.

Viollet-le-Duc was a great master.

-He loved medieval architecture.

I mean, that's the important thing, isn't it?

Viollet-le-Duc's restorations came out of his love of what had been there before.

[ Bells toll ] ♪♪ -I would have liked Viollet-le-Duc to have left a little more of the unevenness and irregularity that would have been visible.

But on the other hand, I think in terms of -- can I put it this way?

-- the sex appeal of Notre-Dame, Viollet-le-Duc was fantastic, of course.

♪♪ -The cathedral is added to the list of historic monuments in 1862.

♪♪ -[ Speaking French ] -When Notre Dame is classified in 1862, this includes the conservation work over the centuries, and Viollet-le-Duc's revelatory work surrounding Gothic art itself.

[ Bells toll ] ♪♪ -The building that becomes a part of French heritage is a hybrid monument.

It is both the work of builders from the Middle Ages, and the ideal cathedral of a 19th-century architect.

♪♪ 700 years after laying the first stone, the cathedral of a provincial city has become the beacon of a major capital.

[ Gunshots ] -In the 20th century, she witnesses the major events in French history.

♪♪ Her bells toll for trying moments.

♪♪ Day after day, she serves as the setting for thousands of memories.

♪♪ She is one of the world's most-visited monuments.

♪♪ With today's major project of reconstruction, the long saga of the builders continues.

♪♪ The restoration work will certainly lead to new discoveries.

But what principles should it follow?

And what mark should we leave?

♪♪