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The Vikings were some of the fiercest warriors of all time,
and a select few carried the ultimate weapon:
a sword nearly a thousand years ahead of its time,
built by a mysterious craftsman
from a material unknown to rivals for centuries.
The sword was known as the "Ulfberht."
ALAN WILLIAMS: The swords were far better than any other swords made
before or since in Europe.
NARRATOR: The secrets behind its design, creation and use
have been lost.
But now the world's largest steel company
and a modern-day blacksmith divine its mysteries
and bring the Ulfberht back to life.
RIC FURRER: To do it right,
it is the most complicated thing I know how to make,
and it's that challenge that drives me.
NARRATOR: A millennium after its time of glory,
discover "The Secrets of the Viking Sword"
right now on this NOVA/ National Geographic special.
Major funding for NOVA is provided by the following...
Supporting NOVA and promoting public understanding of science.
And the Corporation for Public Broadcasting
and by PBS viewers like you.
Additional funding from:
Inspiring tomorrow's engineers and technologists.
NARRATOR: Master swordsman John Clements
has cut with some of the most famous swords ever made...
...from Damascus steel blades
to the legendary samurai sword, the Katana.
Forged by master craftsmen from the 14th century onward,
the samurai sword is renowned for its elegantly curved blade
and impressive cutting ability.
I think the Katana is a beautiful weapon,
it's a fine weapon.
It slices, it cuts, it thrusts, it dices,
it makes julienne fries, it's wonderful.
But it has been exaggerated.
NARRATOR: Exaggerated because sharpness alone is not enough.
So you see demonstrations of a sharp sword like this
cutting material all the time and you think it's impressive
because, "Ooh, look what it does!"
But that's really not that impressive, and here's why.
This is a wide medieval *** sword, and this one's blunt.
It's got no real edge to it.
No edge sharpness.
But watch what I'm going to do with it.
A really good sword is not just about cutting
with a really sharp edge.
NARRATOR: Strength, flexibility, weight and shape all determine
how well a blade meets the combat challenges of its time
and whether it's a superior sword.
Many great swords are famous,
but there's one few have ever heard of
that was perfectly designed for its day.
They were a luxury: rare and expensive.
It was the Rolls Royce of the swords.
NARRATOR: Produced only from about 800 to 1,000 A.D.,
this Viking sword was made from a pure steel
not seen again in Europe for nearly a thousand years.
This high-tech weapon of its time
was inscribed with the mysterious word "Ulfberht."
Carried by only a few elite warriors,
the Ulfberht represented the perfect marriage
of form and function in the chaos that was a Viking battle.
NIELS LYNNERUP: It's not people divide you up and have a nice duel one-to-one.
The fight was very violent.
Chaos.
People moving around,
striking out whenever possible.
Some people were struck multiple times
and from all kinds of angles.
NARRATOR: The Vikings spread out from Scandinavia,
colonizing vast expanses of Europe
from the eighth through 11th centuries.
They are so admired as fighters
that people to this day re-enact their battles.
In Viking times, most men fought with axes and spears.
But those who could afford it used swords for close combat.
The Ulfberht's combination
of strength, lightness and flexibility was an advantage.
WILLIAMS: The swords were far better than any other swords made
before or since in Europe.
And these must have been extraordinarily valuable
to their contemporaries because of their properties.
NARRATOR: Thousands of Viking swords have been found,
most discovered in rivers or excavated from Viking burials
across Scandinavia and Northern Europe.
But only 171 have been identified as Ulfberhts.
JON ANDERS RISVAAG: The swords as they are today,
it's very hard to see that this was actually
a state-of-the-art weapon.
NARRATOR: Buried for centuries,
only corroded skeletons of the once glorious blades remain.
RISVAAG: They don't look very much today, but in their time
the Ulfberht was the weapon of the upper strata.
You would certainly notice a person
carrying a weapon like this.
This would be a very precious, very beautiful object,
and a deadly one too, obviously.
NARRATOR: The secret of the Ulfberht's construction
has been lost for nearly a thousand years.
But can a modern-day blacksmith recapture that technology
and bring this remarkable sword back to life?
FURRER: To do it right,
it is the most complicated thing I know how to make
and it's that challenge that drives me.
I don't need a sword, but I have to make them.
Not because I can't do anything else,
but because I can't do anything else.
NARRATOR: In northern Wisconsin,
Ric Furrer is starting out on the task of a lifetime.
He's one of the few people on the planet who has the skills
to unravel the mystery of how the Ulfberht was made.
FURRER: I'm drawing a full-scale paper model
of the sword blade that I'm going to try to recreate.
This Ulfberht inlaid sword was popular
about a thousand years ago
and nobody has made a recreation
metallurgically accurate since then.
I hope to figure out if I can recreate accurately
how these blades would have been made back then.
NARRATOR: There are mysteries about everything
related to the making of the Ulfberht.
FURRER: These were, to a large extent, secrets.
You didn't want to give away
your manufacturing technology for your weaponry
to anybody else.
So we have to look at the artifact
and then reverse-engineer.
Sometimes it's a matter of removing 1/32 of an inch here
or adding it there or...
subtleties that you don't think matter
that can in fact make a huge difference
in how the blade performs.
The trick is to piece together
from enough archaeological evidence to figure out
what the proportions of these blades should be
and then the chemistry.
What is the material that these were made out of?
And that is new information,
why they're metallurgically different.
NARRATOR: In London, one of the world's leading experts
on historic steel weaponry, Alan Williams,
recently made a discovery about the Ulfberht
that shocked scientists and sword makers alike.
WILLIAMS: I've been fascinated by armor and swords
for a very long time
and have always wanted to find out
what they were made of and how they were made.
Smelted iron was the source for swords, weapons, armor
for thousands of years.
NARRATOR: From about 800 B.C. till today,
humans have made weapons from steel.
The process starts with iron,
which is found in the ground as ore.
The crushed ore is heated to separate the iron from the rock.
But on its own, iron is too soft to yield a strong weapon.
The trick is to add carbon, most commonly from coal or charcoal.
This hardens the metal and turns it into steel.
But not all steels are created equal.
First, Williams examines a sample encased in acrylic
from a typical Viking Age sword.
Not only does it have low carbon,
it has impurities, known as slag, that weaken it further.
WILLIAMS: Medieval iron is both soft and brittle.
This is a sample of a sword of modest quality.
These long inclusions, perhaps looking a bit like sausages,
these are inclusions of slag, the non-metallic part of the ore
which has never been separated from the iron.
The slag makes the iron brittle,
which doesn't actually give you a terribly good sword.
NARRATOR: Medieval blacksmiths in Europe didn't make slag-free steel
because their fires weren't hot enough
to fully liquefy the iron.
In modern times, metals are melted
at temperatures over 3,000 degrees.
This separates out the slag
and allows more carbon to be mixed in evenly.
But in the Viking era,
carbon could only be introduced incidentally,
mainly through the coal in the fire,
and the only way to remove the slag from the metal
was to try to hammer out the impurities with each strike.
Of the thousands of European swords
from the Middle Ages that have been found,
all were thought to have been made from this inferior steel
until Williams analyzed the Ulfberht.
WILLIAMS: One or two swords I looked at seemed to be different.
They were made of steel
which I'd never seen before or since in a medieval object.
This seems to be a completely different material.
The first thing that strikes you is that
there are none of these long, grey slag inclusions
which make the metal brittle.
The uniformity is more like a modern steel
than it is a medieval one.
And it has got a carbon content of about three times as much
as the medieval steel we looked at a moment ago.
I thought it was very odd.
I couldn't think of a reason for it.
NARRATOR: The only swords Williams found
that were made of this clean, high-carbon steel
were those marked as Ulfberht.
The metal, known as crucible steel,
gave the swords capabilities far ahead of their time.
But it could only be made
by melting iron at high temperatures,
and no one in Europe would know how to do this for centuries.
WILLIAMS: The material used was a novel material
not found anywhere else in Europe in the Middle Ages.
FURRER: The biggest mystery is where did they get this raw material?
We have no archaeological evidence
of any crucible steel production in Europe until 800 years later.
NARRATOR: So how did these Norsemen,
widely viewed to this day as barbarians,
get this cutting-edge technology?
Contrary to their image,
the Vikings were advanced in many ways.
They were highly skilled navigators and traders,
who are believed to have extended their reach
as far as North America and Central Asia.
LJUNGQVIST: During the Viking Age in Scandinavia,
all free men were by law
forced to possess weapons and go to war.
But much Viking warfare was raiding and plunder.
NARRATOR: Many Vikings were pagans who worshipped their weapons
and even believed a sword could help a warrior enter heaven.
LJUNGQVIST: The warriors would come to a special place called Valhalla,
where they would have feasts and fighting in a warrior paradise.
The only way to get to Valhalla was to be a warrior
and die in battle with your sword in your hand.
GUNNAR ANDERSSON: The sagas tell stories about the swords, how powerful they were.
Many of the swords had personal names,
sometimes that are connected to, for instance, a bear or a wolf.
By giving it a name,
you could also incorporate the power of your ancestor
or somebody very strong into the sword.
CLEMENTS: See how your whole weapon's blocked
and there's that sweet opening right there?
So you throw that blow,
my point's right between both your weapon and your shield.
NARRATOR: According to John Clements, in the arms race of the day,
blades rarely touched each other directly.
Instead, they pounded against armor and shields
as fighters tried to go for the kill.
CLEMENTS: The reality of Viking combat is
there's not the constant edge- on-edge, blade-on-blade contact.
Yeah, very good.
They're using the shields far more dynamically,
they're getting in close,
they're overwhelming their opponent with vicious blows.
I come in, I hit your shield.
If I don't do it right, you're going to get me.
But if you do, there is that opening,
because you can't raise your shield.
We've got to think of the sword as a tool
that's being used to do things such as warding off blows.
It has to be robust and resilient
because fighting is not just about clash, clash, clash.
It's a lot more dynamic.
NARRATOR: The lack of brittle impurities in the steel
made the Ulfberht unusually flexible,
and this was a huge advantage.
A Viking fighter was doomed
if his sword got stuck in a shield and broke.
It took a special steel to withstand such stress,
and a sword that could do this
might even have been seen to possess magical powers.
FURRER: These blades and these blacksmiths
were held in certain esteem and also feared a little
because of this elemental property of what they're working
and what they're producing.
To be able to make a weapon from dirt is a pretty powerful thing.
NARRATOR: Magic and science
have been intertwined throughout human history,
and the Ulfberht merged the mysticism of the past
with the precision of the modern world to come.
So this is our steel-to-be.
NARRATOR: Starting with raw iron,
Ric begins the process of making crucible steel.
It's the first of many steps on the way to a finished sword.
A mistake at any point could lead to failure.
This charcoal will be the carbon source for the steel,
so the charcoal here will get absorbed into the steel.
And we don't need much.
NARRATOR: If all goes well, carbon from the charcoal
will harden the raw iron into steel.
This is sand,
and this is our bottle glass.
They will melt, chemically bond
with the waste material, the other slags,
and will help float them away and leave clean metal
so the carbon can be absorbed.
NARRATOR: As part of their mystical practices,
some medieval smiths might have used a different carbon source
to strengthen their swords.
ANDERSSON: You can also use bone,
burnt bone, together with coal in hardening the steel right.
And assume now that you're using burnt bones,
even from your ancestor, or from a bear or something like that,
and you hammer in the power of the animal or your ancestor
into the weapon in itself together with charcoal
and you make a perfect steel blade--
a very powerful steel blade probably as well.
FURRER: We are putting the top onto the crucible.
This clay will completely seal this crucible
from the furnace environment.
Mostly it's to keep more charcoal from getting in.
So we want a set amount of carbon.
And if the charcoal were to enter, we would have too much.
And there it is.
NARRATOR: Ric will try to melt the metal in an oven he's building.
It's based on an ancient furnace made of clay and brick
that was recently uncovered 2,500 miles from Scandinavia,
in Central Asia.
FURRER: We fill this all the way to the top, to the tippy top,
because we need all the heat,
so we need all the fuel we can get into the furnace.
The theory is that this is how they did it
a thousand years ago.
Charcoal will burn hot enough to melt steel.
The trick is to get it contained in such a way
that you can deliver that heat long enough
for the material to melt inside the crucible.
Almost finished.
We just have two more bricks
and then we've got it sealed up and ready for the burn run.
If we run this right,
it should get almost to 3,000 degrees Fahrenheit
and we should get a nice full liquid on our crucible charge.
And then we have our starting material for the Ulfberht.
Last brick.
NARRATOR: Closed at the top and vented from the side,
this oven traps more heat
than other European furnaces of the time.
Ric and his assistant, Kevin Cashen,
will man the bellows for hours.
In medieval times, an entire village would help.
The ingredients need to reach nearly 3,000 degrees
for the slag to separate from the liquefied steel.
Even the smallest fracture in the crucible--
the container holding the steel--
could derail the entire process.
FURRER: We're hoping that if we run it right,
we're going to end up with a crucible steel ingot.
But the idea of actually doing all of these steps
and putting it into one piece of metal is daunting
because at absolutely every stage,
you can have a fatal error.
NARRATOR: The Vikings didn't invent crucible steel.
In fact, there's no evidence
that anyone in Europe knew how to make it
until the Industrial Revolution in the 18th century.
But for more than 500 years before the Ulfberht,
warriors elsewhere had been fighting
with crucible steel weapons.
Swordsmiths across Central Asia
produced some of the greatest swords of all time,
known as Damascus steel blades.
Curiously, they were made
from material similar to the Ulfberht.
WILLIAMS: Damascus steel is a separate class of crucible steel
which is similar in chemical composition,
but the crucible steel was cooled very slowly,
so the iron formed large crystals.
And with careful forging,
these large crystals form a surface pattern on the blade.
NARRATOR: These unusual swords exhibited
many of the same superior qualities as the Ulfberht.
But if the Vikings didn't know how to make crucible steel,
then where did they get it?
Clues can be found in artifacts
excavated from Viking graves in Scandinavia
as early as the eighth century.
ANDERSSON: The Buddha was found on an island
west of modern-day Stockholm.
It originates from India, northeast India.
And it tells us, of course,
that trades with the Far East existed.
The ring is the same thing there.
It's this written inscription that says "Allah."
NARRATOR: Thousands of artifacts from the East
have been uncovered from Viking graves.
Islamic coins were even commonly traded in Scandinavia.
You could go mostly by river and lakes
all the way from Lake Mälaren here in Sweden to northern Iran.
NARRATOR: The route was known as the Volga trade route.
LJUNGQVIST: The interesting thing is that most Ulfberht swords are dated
from exactly the same time when the Volga trade route was open--
that is, from the early 800s to the mid-1000s.
I think it's very likely that the steel that you find
in the Ulfberht swords originated from Iran.
I would guess that you bought it
from friendly trading connections in Iran--
paid with furs and other Nordic commodities--
and took it back on your small ships
that you used on the rivers.
WILLIAMS: After the 11th century, the Volga trade route is closed
and the manufacture of these Ulfberht swords stops,
which, to me, is strong evidence
that they were made out of an imported raw material.
NARRATOR: The oven that Ric has used as a model
was found in Central Asia,
near the end of the Volga trade route.
After five hours, it's time to see
if he has successfully made a crucible steel ingot.
FURRER: I think this burned pretty good,
so we should have an ingot in there.
NARRATOR: Most of the impurities have separated from the steel
and been absorbed by the sand and glass
that fall off with the crucible.
FURRER: It seems like we have a good ingot.
Let's see if we can turn it into a good Ulfberht blade.
NARRATOR: This single piece of steel will make the entire blade.
The absence of lava-like sparks
suggests he's created slag-free, pure steel.
But the artistry comes
in working the hard, carbon-rich metal.
FURRER: This part, this initial breakdown, is terrible.
You have to be very gentle with it or you can crack it.
NARRATOR: Crucible steel is difficult to work
because as it cools, the iron atoms form
interlocking crystalline structures called dendrites
that look like frost patterns on a window.
The carbon in crucible steel
makes the areas around the dendrites rigid
and hard to forge.
FURRER: It's solidified into this dendritic tree
and it doesn't want to be anything else.
So you're hitting it and it's kind of all nestled together.
What you have to do is just nudge it,
and slowly it breaks down.
And after that, you really start to enjoy it.
NARRATOR: It will take eight hours of pounding
just to form the ingot into a bar.
FURRER: Two more.
It's breaking down quite nicely.
So now we'll start forming it out into a longer bar
and draw the sword from there, but it's looking real good.
NARRATOR: To test how good it really is,
Ric will send a small piece of the crucible steel he's made
with his ancient recipe
to the largest steel company in the world.
ArcelorMittal produces
nearly 100 million tons of steel a year.
One out of five cars in the world contains its metal.
RICHARD SUSSMAN: In the modern steel world,
we try to customize the recipe for steel
for the particular application,
and so there are now hundreds of variety of steel
which are suitable for some applications,
but not for others.
The Vikings, in their day,
I'm sure wanted hardness on the surface of the sword
so it could cut through easily.
They would want the sword, however,
not to shatter or break in combat.
If it got stuck in a shield,
they'd want to be able to extract it
without it breaking or twisting or bending,
and they'd want it to be able to keep its edge.
NARRATOR: To choose the best metal for a particular application,
Sussman's team tests the capacity
of different types of steel to withstand stress.
Today, they'll pit Ric's crucible steel
against the typical European metal of the time.
As the Vikings raided their way across Europe,
this inferior iron is what an Ulfberht
would most likely have met in battle.
The metal is brittle and breaks like a dry twig.
It would have been a very inferior sword
because it could have shattered in action.
NARRATOR: Now the machine will measure whether Ric's crucible steel
will be able to withstand more stress.
SUSSMAN: The crucible steel that we were given
had actually very nice characteristics for a sword,
which you want to have good strength
but also not shatter in action,
I think good characteristics overall.
NARRATOR: An examination of the microstructure
with a scanning electron microscope
will reveal whether Ric has succeeded
in making a slag-free, pure steel.
TECHNICIAN: As we're moving along here across the surface,
it's quite interesting how clean it is.
NARRATOR: The image is nearly free of slag
and other inclusions that appear as dark circles.
SUSSMAN: The inclusions are very small and very minute
and very widely distributed.
NARRATOR: 2,000 years after it was invented, Sussman--
who has spent decades developing modern steels--
gives Ric's crucible steel what for him is high praise.
SUSSMAN: This would be a fairly decent steel today.
Considering the lack
of metallurgical knowledge in its day
and the tools that were available
compared to steel making today, it's not bad.
NARRATOR: After 11 hours of pounding,
Ric has transformed his piece of crucible steel into a blade.
FURRER: We have the blade profiled, and now we're going to start
refining the tip to its final shape.
So now it's going to start looking like a sword;
it's no longer a bar of steel.
It's going to start to take on its final shape.
NARRATOR: Ric's sword will eventually be more pointed,
like all Ulfberhts.
FURRER: One more.
Flat.
CLEMENTS: The swords of the Norse
tended to be swords that are designed
to get through the mail armor that they're wearing,
the chain linked armor.
And that requires a different point
and a different cross-sectional geometry.
They changed the way their swords were shaped
to facilitate thrusting through that mail.
NARRATOR: To show the advantages of the pointed swords
that emerged in the Viking era,
first Clements tests an earlier replica sword from Roman times
against Viking-era chain mail.
Designed to slash at opponents from horseback,
it has a more rounded tip.
I don't think a single ring
was deformed, split, popped, or in any way damaged.
So obviously a point that's more rounded,
hitting the mail is not going to do as much on puncturing
or on even catching it
as will a narrow, tapered, harder point
that will get through.
So this Viking-era blade has a slight taper to the point.
Sure enough, it popped about two or three rivets--
there is the puncture, there is the cut--
and I could feel the blade getting through the cloth
and getting into that rubber and that foam underneath.
A blade like this,
definitely progress in the arms race between swords and armor.
NARRATOR: The Ulfberht's shape was perfectly suited
to meet the martial challenges of its time.
But its true excellence stemmed from its unusual metal
and from the intangible value of its name.
FURRER: We're at the point now where we do the inlay,
or the cutting of the inlay, for the name "Ulfberht."
We've got the cross.
U-L-F-B-E is more or less centered, R-H-cross-T.
NARRATOR: Like his mysterious predecessor a thousand years ago,
Ric's taking a chance by branding the sword.
(hammering)
FURRER: There is some argument that the cuts actually weaken the blade,
so if I do this wrong
I'll have to start over from the beginning.
RISVAAG: As one might see here, that is the "B" in "Ulfberht."
And as you can see there,
it stands out from the rest of the sword.
If you look closely,
you can see that some parts of the lettering
are actually starting to come off
because it's been through a hard time
both in the earth and through the burial.
But this is a very highly skilled craftsman doing this.
It's not very easy to do that.
FURRER: This is one of the many make-or-break points
in this sword manufacture
because we have to cut the name just right
and inlay the contrasting iron letter
into the crucible steel blade.
So I'll carve it with a few chisels
and then we'll inset the twisted iron inlay.
The fact that they went through the labor
to give it that amount of extra effort,
that amount of power by inlaying this name
made them more valuable.
Why they put this on, it's... we don't know.
We are quite puzzled.
But it might be because it was...
they were making a statement:
"This is the real deal, this is something of quality."
But Ulfberht is actually an enigma;
we don't know who Ulfberht was.
LJUNGQVIST: We have no examples
from the written sources from the time of the name.
It does not appear anywhere.
NARRATOR: So what can this name tell us about who made these swords?
The fact that Ulfberhts appear over a 200-year period means
they couldn't have been produced by a single craftsman.
But the name seems to be Frankish--
from a medieval empire that included France and Germany--
and the signature holds an important clue.
RISVAAG: There's actually a small cross in front of the name,
and ordinary people would not put a cross
in front of their name.
NARRATOR: During the Middle Ages, the Roman Catholic Church
dominated the Frankish empire and more.
A frequent enemy of the pagan Vikings,
the church was a major arms producer and arms dealer.
LJUNGQVIST: The Greek cross before a signature
was only used by bishops and abbots.
And so the signature tells us
that it was either a bishop's name or an abbot's name,
or maybe even the name of a monastery.
NARRATOR: It's possible that the swords were manufactured
by the Vikings' rivals in the Roman Catholic Church
and then somehow smuggled north.
LJUNGQVIST: But we have no way of really knowing
how the Vikings got possession of the Ulfberht swords
since it was forbidden to trade with the Scandinavians.
NARRATOR: If people in the church did make the swords,
it begs the question how they got the crucible steel.
Many experts agree that it was brought by the Vikings
from Central Asia or the Middle East,
so perhaps the Vikings themselves
were the craftsmen, despite the foreign inscription.
WILLIAMS: There are lots of reasons why a Scandinavian
might have used a foreign word and have used the cross.
It might have been magic,
it might have been copying symbols
from the disappeared Roman Empire,
it might have been simply because
somebody thought they liked the name,
like putting the name "Apple" on a computer.
There are dozens of possible reasons
why the makers of these swords
could have used the Frankish name Ulfberht.
RISVAAG: So if you look at this mystery,
this enigma of this person Ulfberht,
who he was and what kind of position he had,
it might not ever be solved.
I wonder who he was, or rather who they were,
or what this inscription meant
to the people that owned the swords.
Because we don't know
if Ulfberht is a kenning-- a word of power.
Could be an area,
could have been a workshop because these spanned 150 years.
So I wonder about a lot of things.
But if you think too much about other things...
...you make mistakes.
NARRATOR: Whoever or whatever Ulfberht may have been,
the inlaid lettering helped reassure customers
they were buying from a master craftsman.
That looks all right.
Let's set it.
Give me one good hit.
NARRATOR: Once the letters are pounded into place,
they are heat treated.
But Ric won't know if they have set properly
until the end of the process, when the sword is polished
and the thick layer of iron oxide that's accumulated
is removed from the surface.
FURRER: I'm putting in all of this work to make this blade.
And if it does work,
you still have hours and hours of polishing
to verify that all the work you did up to that point
actually made a good sword,
and that the letters exist.
And if it doesn't work, it really sucks.
You just end up with a piece of recyclable material.
NARRATOR: With the letters welded in place,
Ric must now make something called the fuller.
The fuller is an indentation down the center of the blade.
It reveals the ingenuity of Viking Age craftsmen.
FURRER: You've got the start of the fuller,
and that will get progressively deeper as we go.
We're just going to bring that all the way up the blade.
The fuller allows longer blades, wider blades,
yet the same weight as thicker, unfullered pieces of steel
because it acts like an I-beam.
An I-beam has structural members here and a horizontal.
So here we have the fuller acting as the horizontal
and a little bit thicker material,
and then going down to a cutting edge.
So you have the minimal amount of material
to give you the maximum amount of strength.
So in this time period,
the blades are getting longer and longer and longer,
but the weight remains about the same.
A completed sword weighs about two pounds, a little bit less.
About like a baseball bat.
Swords weigh about what a baseball bat weighs.
NARRATOR: The fuller made longer blades lighter.
LYNNERUP: You're fighting for your life.
You need to use every opportunity you can to strike.
Some of these Viking swords are heavy,
you just don't move like the Three Musketeers easily.
It takes some force to wield the sword
and having done a full stroke, you need to swing it back up.
NARRATOR: If a fighter didn't get his sword up fast enough
to strike an opponent, he might not get another chance.
These victims of a Viking attack--
found in a mass grave in southern Greenland--
all show clear evidence of blows to the head.
LYNNERUP: In a forensic context, what we're looking at
is the velocity and the weight of the swords.
If we take this skull here,
we can see a very clear marked cut edge.
This is where the weapon struck and actually managed
to cut through quite a lot of the skull
before finally some of the bone here was crushed
and then the sword was taken out.
And this blow would certainly have been deadly.
NARRATOR: When a warrior was killed in violent combat,
the living often took precautions
to avoid his wrath in the afterlife.
ANDERSSON: If you bent the sword,
you also destroy the power of the sword, right,
and you bury it together
with the person that owned it, and in that way,
you made sure that the powers of the weapon
were buried as well and killed as well.
NARRATOR: Hundreds of swords
which were heated and then bent
have been unearthed from Viking graves.
RISVAAG: If you took a sword off an enemy,
you would make damn sure
that he didn't come back in the afterlife
and bother you with the sword,
so it's sort of a ritual killing of the sword, too.
NARRATOR: Ric is heating his sword for another purpose.
He has reached the riskiest part of the entire process.
It's called the quench.
FURRER: The quench is where it's really born.
It's just a piece of metal until it comes out of the quench.
NARRATOR: The goal of the quench is
to harden the sword by heating, then rapidly cooling it.
We know now that this affects
the atomic structure of the metal.
According to legend, ancient blacksmiths cooled their swords
with anything from water to dragon's blood.
But Ric will use oil.
He'll quench the sword when the blade glows
a consistent dull orange.
FURRER: Up until the last few minutes,
all the prior work can be destroyed.
This one has so much technology going into it, so much time.
If it breaks in the quench, I'm going to be absolutely gutted.
NARRATOR: It's uncertain whether the makers of the original Ulfberhts
quenched their swords.
But Ric believes they did, and thinks it offers final proof
of a blacksmith's mastery over the metal.
FURRER: I'm in love with the steel--
this very primal interaction with this raw material
that's largely unforgiving,
and even if you treat it right,
absolutely everything can go wrong.
We're coming up nice.
NARRATOR: The quench will make the blade hard
but it can also crack the sword.
The ping is the audible sound of the steel cracking.
So we hear it as a tink or a ping,
and that means that somewhere along that blade,
it has cracked and we need to start over.
I think we're about there...
We'll know within about ten seconds of the quench
if we got a good sword or not.
I think we're going to go for a quench.
Like maybe right now.
(hissing)
No ping!
Did not crack.
A little bit of straightening-- it's a little bent--
but we can handle that.
I don't think a crucible steel with bloomery letter Ulfberht
has been made since the originals.
So it's been 900 to 1,000 years.
We have an Ulfberht!
I think we've got a good blade.
I want to see the name.
I've waited quite a while to see the name.
NARRATOR: The name will remain hidden
until the sword cools and Ric can polish it.
But after a thousand years,
the mysterious Ulfberht inscription
has one more secret to reveal.
As of today, Alan Williams has examined 44 Ulfberhts
across five countries
and has made one final discovery.
WILLIAMS: Some swords have the name "Ulfberht" spelled
"cross-U-L-F-B-E-R-H-cross-T,"
and some have them spelled "H-T-cross."
Those that were spelled "H-cross-T"
had the very high carbon steel,
whereas the swords
which had the Ulfberht name spelled differently
were made of much lower carbon steel, much inferior steel.
These must have been copies.
NARRATOR: Of the 44 Ulfberhts that Williams has examined,
33 are not made of crucible steel.
RISVAAG: You can see here the R, the H, the T and the last cross.
WILLIAMS: They are contemporary fakes, of course;
they were made at the same time
by people trying to cash in on the reputation of Ulfberht.
They were probably made by illiterate craftsmen
for illiterate customers.
It's the Armani or the Gucci or whatever, or the Porsche,
so you want to copy the brand.
WILLIAMS: To the unsuspecting buyer,
it appears to be the genuine Ulfberht,
but there's a much greater chance of it snapping,
which is, of course, extremely embarrassing in battle.
NARRATOR: Ric's sword is made from crucible steel
and bears the inscription of a genuine Ulfberht, cross-t.
But before his sword can truly be called an Ulfberht,
he must see if the inlaid name has survived the process.
After tempering, or reheating, the sword a final time
to keep it from becoming too brittle, he begins to polish.
FURRER: It can take a few days of rubbing
by all handwork to get these cleaned up
and looking like people assume swords look.
It was the luster of the metal that made people *** after it.
In a world of mud and trees and rock,
you have the polished metal, and that was different.
NARRATOR: He uses increasingly fine grained stones
to polish the sword, and only then will he sharpen it.
But he still can't be sure if the inlay has survived.
FURRER: If the inlay survives all of the grinding,
what will happen is if we add an etchant to it, an acid,
then that should create enough of a contrast
between the two materials
to where the name should be easily readable.
We'll see how well I did.
The cross.
U-L-F-B-E-R-H-cross-T.
It looks really good.
It was a good inlay.
It's gonna be a fine sword.
I think it's worthy of the name.
Worthy of the name Ulfberht.
Here we are talking about a sword
that was made last a thousand years ago.
I see myself as a caretaker of this knowledge.
I can't make a blade better than this.
It represents my entire skill set as it sits now,
sitting there in a two-pound chunk of steel.
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