NOVA

NARRATOR

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... 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. 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 bastard 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. 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. 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. 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. 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 Malaren here in Sweden to northern Iran. 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. 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. 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. 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. 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. 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 lust 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. This NOVA program is available on DVD. To order, visit shopPBS.org or call 1-800-PLAY-PBS. NOVA is also available for download on iTunes.