Original subtitles

In icy Nordic waters,

a mysterious wreck.

There's nothing else like it.

We've never seen anything else like this archaeologically.

The long-lost warship

of a late medieval king.

It's a statement of power... it's floating propaganda.

Sunk under mysterious circumstances

over 500 years ago.

What secrets does it hold?

How did it come to be here?

What cargo did it contain?

We were jumping up and down

and said, "We have found a figurehead!"

That's great, unbelievable.

Yeah, it's amazing.

Written records of the time

described it as a fearsome vessel.

It was designed to project power.

It was a floating castle.

More powerful than

the Viking ships that preceded it.

How was it built to be so large?

We got some things

we don't understand, frankly.

And could it have been part of

the technological revolution that built

the great ships of exploration

that carried Columbus and others

across the Atlantic and around the world?

Designed for the same types of mission,

built in the same way.

This is our look at what Columbus and his crew

actually experienced on their voyages of exploration.

That's what makes this shipwreck so important.

Because it's, it's a treasure, in fact.

There's only one way to find out...

Excavation time.

If it's the ship

that changed the world.

Right now, on "NOVA."

Stora Ek ön.

A small island off the coast of Sweden.

Marine archaeologists Brendan Foley...

Excavation time.

And Johan R önnby...

along with a team of divers,

have come here to investigate

the crumbling timbers of a ship.

It may not look like much,

but they suspect it may be a rare type of warship.

Large portions of the wreck appear to still be intact.

I can see a ship!

I can see the bow, the stern,

the ribs... I can see a ship.

Visible in the sediment,

several tell-tale items.

There are artifacts emerging.

Saw a nice lead cannonball.

And an oddly carved piece of wood,

possibly the remnant of a gun carriage...

built to hold an early type of cannon.

Its distinctive design suggests that this object

dates back to the late medieval era, 500 years ago,

a time of castles and armored knights

and the first stirrings of the European Renaissance.

It's the period of Michelangelo and Leonardo da Vinci,

and it's this period in European history

where a lot of things are changing.

And yet, ironically, this ship

may have been hiding in plain sight since the 1970s,

when amateur divers

first stumbled across it

without realizing what they'd found.

Fishermen had told that every time

they was fishing at this place,

they got stuck with the equipment.

And they say, "We go down here and look."

And Neesa got down,

and when he come up, he said to me, "I don't know.

Must be some, a wreck."

That in and of itself wasn't unusual...

shipwrecks are common in these waters.

And then archaeologist Niklas Eriksson

found a strange artifact,

and the wreck started to make headlines.

So I was swimming back and forth

and having a look at

the loose timbers that are lying scattered around there.

I found a thick beam.

After removing some sediments,

we came back to the surface

and we were jumping up and down and said,

"We have found a figurehead!"

It was, it was quite amazing.

Centuries ago, this bizarre, intricately carved figurehead

would have been one of the ship's key identifying features.

It's clearly some kind of monster,

similar to the fantastical creatures

that often adorned old Viking ships.

In its jaws, a screaming man.

I think it's, you can see it as part of

the psychological warfare, really, because this is

the first thing you meet when it's coming.

As propaganda goes,

this is pretty powerful stuff.

But the figurehead alone

was not enough to make a positive I.D.

Military historian Ingvar Sj öblom

soon put the clues together.

It was probably a very rich man

that, that could, could have the money to build

a large ship of this size.

Along with other clues gleaned from the wreckage,

the figurehead and gun carriages suggest

that this could be the flagship of a Danish king named Hans.

Over 500 years ago,

the monarch was famous for building a large naval fleet

led by a massive warship known as the Gribshunden...

"the Griffin Dog."

It's the capital ship of King Hans.

It's the aircraft carrier.

It's the ballistic missile submarine.

It's a statement of power... it's floating propaganda.

Now I really understand what's down there.

Four chronicles mention Gribshunden by name,

as does a single eyewitness account,

written by a young nobleman who survived the ship's sinking.

They report that in 1495,

the Griffin Dog came to this island

seeking shelter, before sinking...

under strange circumstances.

The finds yesterday were

really exciting, quite spectacular,

and I think we're going to have

the same today, so...

Now, Foley and R önnby

are preparing to uncover this ship's secrets.

The work won't be easy.

Though the wreck is not in deep water,

it's mostly covered in heavy sediment.

Excavating requires a highly skilled support team

and extreme caution.

You'll be told who is the dive leader for that rotation,

and their word is God.

To keep them safe as they work,

dive safety officer Phil Short and his crew

will monitor the divers at all times.

It is a shallow site,

but you can't breathe water at nine meters or 90,

so safety is absolutely paramount.

Their base of operations

is a 30-foot dive boat

hauling up to ten divers and their gear.

We can jump in the water and get to work.

And you can take samples.

A temporary lab back on shore

is set up to process any artifacts they recover.

Their time is limited.

They only have the dive boat

and this team together for 16 days.

Their first objective

is to understand how much of the ship

is still intact beneath the sediment.

We have to excavate further down.

So we have to remove the silt around it

so you can get the whole structure of it.

The first step is to expose the cargo hold,

all the way down to the hull,

itself a critical clue.

Only once the sediment is stripped away

will they get a sense of what kind of ship this was

and what it was carrying.

But before they remove a single handful of sediment,

the archaeologists need to create

a virtual copy of the undisturbed wreck.

Each day, a pair of photographers

films and photographs the site.

High-definition video offers

a detailed visual record of the archaeological work.

While a second camera records thousands of stills.

So basically what I'm doing is,

I, I physically have a camera, an underwater camera,

and I'm just swimming back and forth

in a rather systematic way, back and forth on the site.

The roughly 4,000 images are then run through

a program that stitches them together,

producing a 3D model in a process called photogrammetry.

And then the last step is,

we basically take and we lay the photographs on top

to give it a photorealistic view.

Each day, fresh images of the site will be captured,

allowing archaeologists to

digitally retrace their steps

even after excavation is complete.

So we'll see where things came from in the 3D space.

And I think that's the really, really interesting thing

about this technique,

is that we can see this every day.

Yeah, mm-hmm. PACHECO-RUIZ: Which is fantastic.

You can see the progress.

Mapping expert Paola Derudas

can use this first model to create

an even more detailed version.

Yet even now, they can clearly see

the first major obstacle:

piles of loose decking blocking their access

to the lower levels of the ship.

A complete ship

would be easy to understand for what it is.

But if you imagine the top half to two thirds

of that ship essentially sort of taken apart

and collapsed in on itself,

what you've got then

is the seabed scattered with timbers

lying in all directions, and it looks very confusing.

Like a game of pick-up-sticks,

each timber must be moved out of the way

without shifting or damaging the rest of the wreck.

It has to be very carefully controlled,

because sooner or later, we're going to come across

an area where there are

particularly valuable things.

A marine deposit like this, it's very insubstantial,

it's very, it's not compact.

It's soft.

The challenge is to actually excavate that

with enough precision

to not damage anything,

not lose anything, and derive

as much of the archaeological information as possible.

So the team installs scaffolding.

We'll move it into the wreck,

so it ends up here.

Not only to minimize damage to the site,

but to map the location of artifacts and other features.

We're all set up, we're ready to roll.

We're going to excavate.

It's what we're here to do!

But as soon as they set out,

they run into a problem.

The conditions are terrible.

It's really easy to stir up the sediment.

Destroyed visibility to virtually zero.

Their only option:

to use a hand-held dredge...

essentially, an underwater vacuum...

to try to direct the powdery sediment away from the site.

Dredge is working beautifully.

The visibility's fantastic.

And then, finally,

they spot something significant in the clearing mud.

- Chain mail. - Wow.

It's really, really fragile.

And it's within leather, as well.

Oh, that's beautiful.

Oh, wow. Lovely.

And it's all clumped together, this, they're all rings.

Mm.

It could be the end of a sleeve,

and then it could've been connected to mail of iron.

Incredibly, it's a fragment of medieval chain mail,

possibly worn by a soldier, or even a medieval knight.

That, that bit is uncorroded.

It's an astonishingly lucky find.

Sea water is brutally corrosive to metals.

Usually aboard ships,

you have heavy infantry,

and at this time, it was typical

for the heavy infantry to wear plate armor,

and also some mail, which is great protection

against swords and other sorts of, of weaponry.

Not far away,

additional evidence of warfare.

And you saw the, the lead shot. Oh, yeah.

From the gun, cannonball.

Yeah, that was fantastic.

Cannonballs

and more gun carriages.

We have found

nine gun carriages that is salvaged.

We know that it's others down in the wreck.

The weapons themselves are gone, salvaged or rusted away.

But the carriages offer some insight.

The wrought-iron guns are really the predecessors to, to cannons.

So, they've only got a bore of maybe three inches,

but that's a big gun for the time.

They are some of the earliest cannon-like weapons

to be adapted for naval warfare.

Yet the records are unclear if they were ever used in combat.

Only five historical sources describe Gribshunden,

with few details.

Instead, most of the focus is on King Hans himself.

When we look at the written sources,

they describe King Hans as witty, as wealthy,

as kind of a happy-go-lucky man,

and they even describe his good looks.

Hans, like other European rulers at the time,

was fighting to establish his supremacy.

These guys really needed to show that they were powerful kings,

and having a big ship,

with a lot of flags and paint and so on,

it's a way to show that you're something special.

I think this is one of the reason why King Hans

is so keen to have this kind of ship,

to really demonstrate his power.

Records show that Hans took his massive new warship

on diplomatic voyages to Norway, down to England...

perhaps even farther, to Nordic colonies in the west.

We have to imagine the ship as a novelty,

something perhaps hereto unseen in the Nordic countries,

and the fact that King Hans uses this ship,

this is something he'd do

in order to make a political statement.

In 1495, records show Hans outfitted his warship

for yet another expedition, this time to Sweden,

when an unexpected storm forced him

to take shelter near the island

of Stora Ek ön.

Which must have been a very good place to anchor,

because it's quite open sea

outside of the island, but if you go around it,

on the inside, it's quite shelter.

It's a good anchor place.

The records disagree on what happened next.

But based on the artifacts the team is now finding,

it appears Hans was prepared for a fight.

Weaponry continues to emerge...

this time, a crossbow.

Crossbow.

Has a crossbow bolt with it.

Wow, wow!

It's a really interesting

time period, where you still have...

Exactly... the bow and string weapons.

Yeah. When you're getting the projectile weapons

with gunpowder.

Though the Gribshunden did have larger guns,

records are unclear whether handheld firearms were used.

Instead, King Hans likely relied on crossbows.

We know from 1507

that King Hans, he stipulates that

half of the crew members, or half of the soldiers,

they would be equipped with crossbows

and the other half with lances.

Though not as advanced as gunpowder weapons,

they were no less dangerous in the right hands.

More than strong enough

to penetrate an enemy soldier's armor.

It's absolutely deadly.

Chain mail, this can go through.

I've tested it.

Hello, Lena. Not bad.

Hey, I'm Brendan. Hi, nice meeting you.

Lena Eklund is

a world champion crossbow shooter,

beating both her female and male competitors.

In the rules, it says that you have to name

the best woman, because they think women won't win.

But last year, I did win, so they had to name the best man.

Foley has brought her a 3D print of the crossbow stock

recently found onboard the Gribshunden.

So I'm really curious to compare it against your working bow.

Yeah, of course.

This is my stock.

You had to have a stronger bow on that,

I think, than I have on mine.

But how, how effective would that be?

You could absolutely shoot through chain mail

and maybe through armor, too.

However, crossbows couldn't be reloaded quickly.

On land, that meant taking cover behind fortifications,

like castle walls,

while at sea, medieval drawings show they relied on

floating castles.

It's possible the planks the team found

scattered on the surface of the wreck

are remnants of such a defense.

I think this crossbow helps establish the idea

of this ship as basically a floating castle.

That term forecastle goes back to ships like Gribshunden

that quite literally were floating castles.

They had ramparts sort of built up

at the forward end and at the aft end.

Sterncastle, forecastle.

These castles were a critical element

not only for protecting crossbowmen and soldiers,

but for attacking, as well.

One tactic was to try and get your forecastle,

which was a big powerful structure

on the bow of the ship,

if you could get that

over the waist of the other ship,

that would give you an advantage.

You could shoot down on the decks.

They were literally, I mean,

you know, we use the term floating castles.

They were.

And then, they find something

truly unexpected.

Well, looks like a handgun.

The metal doesn't survive, because iron degrades

in this sort of chemical environment underwater.

But the wood survives very well.

That's fantastic,

'cause it's, it's in such complete condition.

It's an arquebus,

one of the very earliest handheld firearms.

Oh, let me tell you how excited I am about that gun,

very excited.

This is possibly the, the oldest handgun

found on a shipwreck, so it's absolutely unique.

It appears King Hans was surrounded by

the most advanced weaponry

of the medieval era.

What Gribshunden has proven to be

is a combined arms platform.

We've got medieval weapons like a crossbow,

even older weapons like pikes and stabbing weapons,

but we've also got this new thing,

these gunpowder weapons, and that's really something.

And yet, the team is starting to suspect

that the most powerful weapon in King Hans' arsenal

may have actually been Gribshunden herself.

As they dig deeper into the wreck,

R önnby and Foley

suspect that this ship may have been

one of the most advanced vessels of her time.

The final proof will be in the hull.

How was it constructed?

If this is the Griffin, can it reveal anything

about the transition from earlier ships,

like the smaller, Viking-style craft,

to the super-sized long-distance vessels

that would come to dominate European fleets?

Previously, European ships were built largely using

traditional designs handed down for generations.

In Northern Europe, where Gribshunden sank,

that meant building ships

much the same way that the Vikings had built

their fearsome longboats.

One of the most distinctive features of

these ships were their hulls.

You can't mistake it.

You'll see the strakes, if you'll notice,

this sort of line of planks running from bow to stern.

And you can see the ribbed appearance,

the sort of, the lapped appearance.

A boat's hull is essentially a shell

built around an interior that is lighter than water,

which keeps it afloat.

For thousands of years,

northern shipwrights built their "shells"

in a very distinctive way.

This is a long, long tradition for almost 2,000 years,

to build boats like this.

And typical for that is that you have

the boarding planking overlapping like this, this way,

and then you put a nail through the, through the planks

to keep them together.

Known as clinker hulls,

they rely on long planks of wood that are slightly overlapped

and then squeezed together

with rivets

to produce a sturdy, seaworthy wooden shell.

Once the outer planks were in place,

internal supports were added to give it additional strength.

These ships were typically equipped with

a single mast and square sail.

The use of the single square sail

in the north of Europe, again, goes back many centuries.

It's a technology that was very well-controlled,

very well-known, and very simple to operate.

A big square sail of the period would've been better at

driving the ship with the following winds.

The resulting ship is light

due to its thin planks and fasteners,

sitting high in the water and reducing drag.

They were excellent sea craft.

They ride with the waves, they don't smash through them.

But their design also makes them flexible.

Years ago, when they were still building the replica

of the long Viking ship from Roskilde,

the master shipwright,

he grabbed one of the posts and shook it,

and you could see the entire vessel waving

all the way to the end, the other end.

It is that flexible.

But this flexibility is

also one the major limitations of the clinker design.

As ship size increases, flexibility becomes the enemy.

Boats should not be flexible.

The history of shipbuilding is the history of

making sturdier and less flexible hulls.

With the introduction of heavy cannons,

clinker ships faced serious stability and stress issues.

As the stresses increase with the size of the vessel,

the fasteners that you need to use

to put these planks together

are going to become less sturdy.

They start making water.

Much larger than the typical Viking ship,

the Gribshunden seems to have also been sturdy.

In fact, as the chronicles show,

King Hans used it to make multiple ocean voyages.

And that is what intrigues the archaeological team.

This ship must have been built

using a different kind of construction.

The archaeologists need to uncover the ship's hull

and interior structures to learn more.

After shifting the timbers

blocking access to the lower levels of the ship,

the team can now begin excavating in earnest.

And I'm actually going to

excavate on the outside of the ship,

for about taking that down as deep as possible.

The excavation is going very very quickly now.

We have four highly competent

teams of excavators.

Now it's starting to become clear.

Now we can see exactly where we are in the ship.

If they want to figure out

exactly how unique the Gribshunden was,

they need to uncover a key piece of the ship's structure...

its hull.

But given their constraints,

they'll only be able to excavate within a narrow area

marked by the frame they've placed amidship.

The middle of the ship,

in terms of the hull design,

it's the most diagnostic place.

So we wanted to get a look at the structure at that point.

It's always hard to know where, where to dig.

We wanted to have quite a lot of the interior of the ship,

so it's a combination of, get so much ship construction

as possible, but also get the inside of it, the cargo.

And then,

a new problem.

Some of it's missing.

We are missing a part over here.

They're looking for the hull of the ship,

and where it connects to the internal structure...

its skeleton.

If they succeed, it could be the earliest hull segment

of a ship of this period ever discovered.

But something isn't right.

We've been wondering, since we started,

the inside of the ship meets the frames here.

So the frame... this is the hull of the ship curving up here.

And we always wondered, there's collapsed timbers all around,

and we don't understand, frankly, what happened

to the hull above this point.

Looking at the wreck, they suspect that the missing section

of hull was not built using the local clinker style,

like the Vikings used.

That wouldn't have been sturdy enough.

But there is a possible alternative

for this ship's construction...

a style found hundreds of miles away, in the Mediterranean.

For thousands of years, Egyptians,

Romans, and others all used a similar template

for their ships.

The ways of building ships go back to at least

the early third millennium BC.

So that's nearly 3,000 BC.

But the Romans and their neighbors used

an entirely different approach to hull construction.

Could the Griffin have been built like a Roman ship?

The clue is in the planks.

Unlike clinker hulls, where the planks are overlapped,

the ships used by the Romans and others had planks laid flush,

then locked together using dowels and joints

similar to those sometimes used in furniture.

The planks are carved, they are each fastened

to each other with mortise and tenon joinery.

And it's been called by some people cabinetry

rather than carpentry.

But it works.

Like clinker hulls, this outer shell

was strengthened afterwards with internal supports.

The result was a smooth-sided hull that was incredibly sturdy

but labor-intensive.

They would last forever,

but they were very difficult to build.

Very expensive to build, many man-hours.

So, whoever were the guys that were carving,

they had to be experienced.

As a result, by the medieval period,

shipbuilders began changing their methods.

This technique that's lasted

for three-and-a-half to four thousand years

gradually starts changing.

They've started to morph into something else.

Instead of building the sturdy outer hull,

and then adding internal frames afterwards,

shipbuilders began experimenting with the reverse,

starting with the internal frames first.

It doesn't sound a particularly radical move,

but if you think about it,

you've got to know the shape of your ship to cut the frames

to put the planks on.

This skeleton-first style was more technically challenging

to design, but allowed shipwrights to control

a vessel's shape more precisely...

and thus its desired features,

such as speed, size, and cargo capacity.

You're controlling the shape of the vessel by building

the frame structure first.

There is geometry.

There are understandings of physics that go into it.

Allowing them to build larger vessels.

This is the craft of shipwrightry

becoming the science of naval architecture.

One type of ship to use this more robust engineering

was called a caravel,

possibly imported from the Arab world.

The Arabs were amazing sailors.

It's very possible that caravels could have been invented

in the northern shore of Africa.

Their design made them incredibly capable.

Starting first as small fishing vessels,

the caravels were soon adapted by Europeans to explore

the coast of Africa,

while Columbus took two of them...

the Niña and the Pinta...

on his first voyage to the Americas.

Caravels became famous

for being swift and fast, and there's an English text

that says, "They, they swirl around our warships

like butterflies."

Could the Gribshunden be one of these advanced

new caravels?

If so, it's unlike any other known example.

To begin with, the wreck of the Gribshunden

is nearly 115 feet long.

The largest known caravels...

which might have included the Niña and Pinta...

topped out at around 75.

Caravels were very good at what they did.

But they're quite small ships.

Nor is it likely the Gribshunden is simply

a longer version of a caravel.

Building a ship is a trade-off between size, speed,

and capacity.

Caravels were optimized for speed,

combining a sleek hull usually with triangular sails

called lateen sails.

A lateen sail

gives you slightly more flexibility in the sense that

it will act more efficiently, like an aerofoil,

and allow the ship to sail across the wind

or even a little into wind.

Lateen sails are agile, but they have a drawback.

There is a big problem

with lateen sails, is, when they get big, you need big crews.

Increasing a caravel's size thus required much larger crews.

Yet the caravels... with their quick, narrow hulls...

didn't have room for the extra supplies required.

The limit with caravels is size.

If you do not have space to put

food and water, you cannot go far away.

So you need large vessels.

Based on everything the team is seeing,

this wreck is clearly not a caravel.

It's a new design, something longer, wider,

and, as the team is now finding,

carrying a huge amount of supplies.

Barrels, barrels, barrels.

Barrel staves, barrel heads, barrel hooping.

Even after 500 years underwater,

the wood looks perfectly preserved.

A symbol has been carved into each lid,

though its meaning is unclear.

To learn more,

the team takes the barrel staves back to shore,

to scientist Hans Linderson.

Linderson is a dendrochronologist:

an expert in tree rings.

We can be very accurate,

but it's very hard to do on, on this waterlogged oak.

In addition to the barrels, Linderson's lab

also analyzes the origin of the timbers used in the ship itself.

He begins by shaving

the waterlogged outer wood away,

revealing the preserved tree rings below.

We cut it like this

and make the surface perfectly clear.

Chalk helps the rings stand out more starkly.

So we try to make it white by chalk.

Then, using a microscope, he measures the width of the rings.

The tree ring started here,

maybe in the end of May,

and grew like this until the end of July

or maybe the beginning of August.

Each year, a tree adds another ring of new wood as it grows.

But some years are better than others.

A drought year might produce a thinner ring.

A long, wet summer might produce a thicker one.

Thus, the tree rings becomes a sort of fingerprint,

a unique reflection of the weather in the specific time

and place where this tree was growing.

I measure every ring.

I try to get as many rings as possible.

And then threw it out in our database.

Linderson's records include an estimated

50,000 reference samples,

allowing him to zero in on exactly when this wood was cut,

a precise ten-month window starting in late 1482.

1482, '83,

that is the youngest tree ring we have...

1482, in this, in this ship.

Maybe after, like, August, they have cut the wood.

But Linderson's database also reveals something odd.

The wood doesn't seem to come from a Nordic country.

Well, in this case,

we saw the sample didn't fit to Sweden.

Instead, it seems to have originated

from hundreds of miles away.

It was close to Northwest France.

It's possible this Danish warship didn't come from

a Scandinavian country at all.

Its timbers are French.

Even more interesting, Linderson's analysis

indicates the barrels holding the ship's cargo

come from yet another part of Europe.

We also determined

the place where they have been growing.

They come from Scania, Southern Sweden,

and also from Poland.

Okay.

That's interesting.

My colleagues tell me that Poland had a huge export market

in making barrels and shipping these out

all over Europe.

But dendrochronology cannot reveal exactly what

these barrels carried.

Fortunately, more clues are emerging from the wreck.

I think we are in the, in the

kitchen store or something like that,

because there are so many barrels down there. Yeah.

In one of those barrels, bones.

And I just couldn't see if that was

wood, or bone, or what that was.

What, what is that?

Mysterious skeletal fragments.

But they don't appear to be beef bones

or other common food animals.

Okay, so, Brendan, the bones that we recovered

are called scutes.

Based on a few of the scute fragments that you excavated,

they are the remains of something

that's at least one meter,

and probably around two meters long.

So it's quite impressive.

They are bones from an Atlantic sturgeon,

a massive fish all but extinct in these waters.

It's kind of like bony plates

that works as a shield construction on the fish.

I think that

this fish would have been used to be presented as a gift

to the royalties.

Because the sturgeon was considered

one of the king's fishes.

A fish considered so valuable

that if caught, it must legally be given to royalty.

And you would be punishable by law.

And, you know, you don't want to be punished by law

during the medieval, right?

There's a lot of evidence for this actually being

one of the things that they would have had with them

as a manifestation of power

or their, just, royal status.

As they dig deeper into the cargo hold of a king,

it's like a window into long-forgotten lives.

We were excavating

down in the hold amidst all those barrels,

and I thought at first it was a gun.

But it's not a gun.

It's some sort of vessel.

What we have here is a

completely intact wooden tankard from 1495,

handle, cover, completely intact,

and possibly the king's mark on it.

The experience of excavating on a site like this

is really quite visceral.

Every once in a while, though, we'll find an object

that just makes us realize

that we're looking back half a millennium in history.

And you think some nobleman was the last one to hold

these objects 500 years ago.

And it's this sense of, of almost time travel.

That's the real benefit of archaeology.

You're traveling back in history in quite a unique way.

And I will say that written sources

can never get you that close to history as,

as archaeology sometimes can.

And then, something puzzling.

Keep your hand on the bottom of it.

There's good stuff in there.

Excellent!

It's like a leather pouch.

They have found what appear to be corroded lumps of metal

wrapped in leather.

It's difficult to tell what they once were.

But there may be a way to find out.

In the wreck, up close to the, to the top

of the surface of the sediment,

we found what we think is a leather purse

that was full of

this material.

So, if the machine can show us

what's in there...

I think we can do that. Excellent.

The solution is a CT scanner,

similar to that used by doctors to peer inside the human body.

So this just goes from the bottom up.

Okay, that's cool already.

You can already see that there's, there's coins there. - Mm-hmm.

It's a stack of coins.

So, it's a lot.

- It's a lot of coins. - Mm-hmm.

Yes.

The question is, what are they worth?

It's a small fortune, perhaps belonging to a nobleman.

It seems strange.

Based on the military artifacts,

it appears Gribshunden was outfitted for battle.

Yet she was also hauling what appears to be

large amounts of food

and wealth.

What were King Hans and his men doing here?

To understand the odd mix of wealth and warfare,

the archaeologists need to understand more about this ship.

And now they're close.

Oh, what wouldn't I give to be able to get there?

I mean, this is so promising, because if we have

these things here,

and we have, we will have the rest here,

I'm quite sure about that.

Why would it disappear?

Down on the seafloor, Johan R önnby

is the first to see it.

It's beautiful.

Yeah.

They have found a remarkable piece of the ship

that reveals the secret of its construction,

and perhaps the construction of other European great ships.

We've got this piece of the hull

that's collapsed outwards,

but it's done so in one lump, one coherent unit.

In a way, it's better than if it had stayed above the seabed,

because it would all be eroded and, and grotty.

But now it's gone flat and it's covered up by about

a meter of sediment... it's in pristine condition.

This key piece of the hull was preserved intact

simply because it had been buried.

It's a tremendous stroke of luck.

At some point, either when the ship sank or afterwards,

this entire section of hull collapsed outward.

But what we're seeing is, this piece that's hinged down

is still going under the sediment.

That's just fabulous.

No, we are quite happy now, because

the whole ship is actually there.

And that's, our excavation now really proves that.

They have finally found the evidence

that shows how this ship was built, from the hull...

the skin of the ship... to the meticulously crafted timbers

that make up the interior skeleton.

And in these timbers, the archaeological team

sees the evidence of a new kind of ship,

its hull built not in the overlapping clinker style,

but not purely in the style used by Mediterranean ships

like caravels, either.

So you've got fastenings, you've got bolts, tree nails,

the wooden pegs that hold everything together,

and we've even got some, I mean, we've got some things

we don't understand, frankly.

But deciphering this incredible discovery

is slow work underwater.

So instead, back on shore,

the team's digital specialist, Paola Derudas,

processes the photogrammetry images into a digital model.

Yeah, that's, that's quite amazing.

It's a high-fidelity copy of the wreck site,

offering an up-close look at their long-hoped-for discovery.

Now we get to see

the shipwreck in its entirety for the first time.

When you're down there, you can only see

small part of the ship.

To have an overview like this is quite amazing.

It's the earliest surviving example of the first generation

of ships built in an incredible new style.

As they had suspected, the construction is different

from the clinker-built hulls of the Vikings

and other northern ships.

Part of the hull, you can actually see that

it's not the way that ships were built

in the earlier medieval period.

It doesn't look like this.

Nor could it be classified as a caravel, so well-known

in the Mediterranean.

This one right here, Paola, if you can get...

This one? FOLEY: Yeah.

The cuts in it right there. Huh.

This is fantastic to see one!

For the first time, we can see how they were built

and how much space you had inside them.

Instead, it appears to be both,

incorporating elements from each region

into a single, unified design.

A new generation of ship.

So this is Mediterranean style, this is clinker.

The dimensions

are clearly different... the width and the depth. Yeah.

They can see in the timbers that the blueprint starts

with a caravel-like hull borrowed from the Mediterranean.

But it's wider and heavier than the sleek caravels,

giving it additional capabilities.

Because its framing system is so much more robust,

you could build your ship bigger and tougher,

and therefore it's much more predisposed to carrying

lots of cargo, people, and weapons.

Above it, lighter boards

are used for the fore and aft castles,

similar to the northern, clinker-style hulls.

The rigging appears to be also northern,

featuring large square sails on two of the masts.

But it adds triangular lateen sails,

used by Mediterranean ships like the caravel,

added for versatility.

They arrive at this sort of technological fusion of features

that makes a more versatile

and seaworthy and controllable ship.

Its sea-keeping qualities are good and it needs less crew.

It would've been as high-tech as there would've been around

at the time.

It was a new kind of design

that would soon change the world.

You can think about the late 15th century

as a sort of space race, in the exact same way

that the Americans and the Soviets and other nations

were competing on a national scale to achieve

a technological feat.

That's exactly what was going on in the late 15th century.

All the European powers now began to develop this ship type.

With Gribshunden, King Hans was one of the first to deploy

one of these technologically advanced new ships.

Heavily armed, he used it to intimidate.

Hans was the powerful ruler of three nations...

Denmark, Norway, but also Sweden.

It was known as the Kalmar Union,

but the union was troubled.

It was quite the problematic relationship,

because there was a lot of

noblemen and, and powerful people,

so it was a power struggle all the time.

And that's really why Hans is, is here.

Records show that Hans was on his way to scare

a rebellious Swedish nobleman back into line.

This was a vessel that was floating propaganda.

It was really a floating castle.

When Hans turns up with his whole fleet, and Gribshunden

is there as one of the principal warships of his fleet,

he's making a statement.

This was raw power on display.

And then, misfortune strikes.

As a storm rages out at sea, Hans anchors Gribshunden

in the sheltered waters

of Stora Ek ön.

Yet danger still lurks.

The written sources suggest

that the king's sort of sorcerer says that the omens are bad

and the king should get off the ship, and he does.

And then the ship catches fire.

Which is partly borne out by what we're seeing on the seabed.

And we do see some of the timbers that are blackened,

which are consistent with that.

And the fire reaches

the powder magazine, and there's some sort of explosion on board.

It's possible that in this way, Gribshunden was a victim

of her own nature as a cutting-edge weapon of war.

Fire today is still probably the first or second killer of ships.

Did they not yet develop the protocols to handle fire

in a ship carrying gunpowder?

Is that why Gribshunden was lost?

It very well could be.

They hadn't yet developed the methods to keep the ship safe.

It had to have been an incredible loss for King Hans.

Yet now the ship has become an invaluable gain

for nautical history.

No other vessel from this first generation of massive ships

still survives.

Gribshunden, I think, takes us back

as far as we've got so far to this period of change.

Europe is changing, and ships are the tools of that change.

You start having more contact.

And there is economic growth.

Cities grow, literacy grows.

Because of population growth

and economic momentum, ships of both areas

start to trade in each other's waters.

And so you get this sort of technological diffusion.

We begin to get a picture

of the late medieval world and all of its interconnections.

And once these different regions

start learning from each other,

everything begins to change.

Whereas King Hans sees the potential of these ships

as an intimidating weapon,

others see a vessel capable of pushing farther

than ever before.

What you're building is not only a ship that is tougher

and bigger, you're building it in a design which not only has

capacity for cargo,

but it's got accommodation built into that architecture.

This is when we start to see ships

going across the Atlantic for not just days,

but weeks or months at a time, or even a year or more.

These are the ships of the age of global exploration.

The shipbuilding advances of this period

would be used by Columbus,

Magellan, and those that followed

to expand Europe's influence,

laying the groundwork for empires

that would transform the world,

even as they enslaved peoples around the globe.

History might have played out very differently

without this novel ship design,

its secrets hidden in the wreck that was lost

for 500 years.

But now this missing chapter of history is restored to us.