Secrets of the Shining Knight

PBS Airdate: October 4, 2017

NARRATOR: Revered as heroes, knights in shining armor were elites, covered in skins of gold.

TOBIAS CAPWELL (The Wallace Collection, London): It's meant to be awe-inspiring. It's meant to blow your mind.

NARRATOR: Their armor embodied a revolution in metal making.

ALAN WILLIAMS (The Wallace Collection, London): These armors were very much Rolls-Royce's of the day.

NARRATOR: But how were they made? The secrets behind their construction have been lost.

RIC FURRER (Door County Forgeworks): When you start asking the questions of, "how did they actually do this?" There aren't many easy answers.

NARRATOR: Now, a team of craftsmen will try to solve the mystery and make an armor from scratch.

JEFF WASSON (Armorer): I don't think that anybody has really tried to do this using old techniques for hundreds of years, so it's a lost art.

NARRATOR: But could these armors stand up to a powerful new weapon? Their work will be put to the ultimate test.

JONATHAN TAVARES (The Art Institute of Chicago): It's a little scary, all this, months of work…

NARRATOR: What happened to the legendary knight as the battlefield changed? Secrets of the Shining Knight revealed, right now on NOVA.

Polished perfection itself, the armor worn by medieval knights was both beautiful and functional. It represented a major technological innovation. But amidst the masterpieces there are marks left by another innovation.

What could have caused these dents? It's not widely known, but for more than 200 years, knights in shining armor and guns coexisted on the battlefield.

TOBY CAPWELL: Knights were some of the first people to take up firearms. They weren't the backward, out of touch people that we often imagine, no way.

NARRATOR: But could they keep up in this medieval arms race? Did guns usher in the end of the knight in shining armor?

The image of the knight goes back to the legend of King Arthur and his Round Table. Arthur's fabled reign in the sixth century inspired a medieval tradition of noble warriors living by the codes of chivalry and romantic gestures of courtly love. These customs flourished across Europe. Knights were elite warriors, fighting to protect the lands of feudal lords and kings and expand the power of the church.

Long before guns, knights battled on horseback and on foot. They fought with swords and lances, which they trained to use in tournaments like this modern-day competition in England. But in a medieval world of stone and mud, it was armor that elevated them to near godlike status.

TOBY CAPWELL: Put yourself in the position of an ordinary person. To see an armored knight, it would have been like seeing the sun manifest in human form. They are the wielders of divine power: "Look at me. I'm radiant."

NARRATOR: But behind this exalted image, a great transformation was brewing. Feudal fiefdoms were giving way to the rise of nation-states, like England, France and Spain, with large standing armies.

PAMELA SMITH (Columbia University): We have all kinds of romantic notions about knights, but this period is one of real change. There was great competition, great military needs that were driving very new technologies of war.

NARRATOR: To keep up in this arms race, armorers created superhero suits that represented a revolution in metal making. And a select few were crafted with secret techniques that made them stronger than others, possibly even bulletproof.

ALAN WILLIAMS: These armors were twice or three times as hard and strong as the armor which the ordinary foot soldier would have to wear. You would be safe on almost any battlefield.

NARRATOR: But the knowledge behind their construction has been lost.

TOBY CAPWELL: There are no surviving period texts on how to make and how to harden and temper armor.

KEITH DOWEN (The Royal Armouries, United Kingdom): We don't know much about the details for the construction of armor anywhere. Armorers simply didn't write down their craft. This was something that was learned over many years of apprenticeship. What armorers didn't want was for their secrets to get out.

NARRATOR: Now, a modern day armorer is trying to solve the mystery. Working from his backyard forge in suburban Long Island, Jeff Wasson is a leading craftsman of medieval armor.

JEFF WASSON: I don't think that anybody has really tried to do this using old techniques for hundreds of years, so it's a lost art.

NARRATOR: An art perfected during a key moment in scientific history.

PAMELA SMITH: This is the period of the Scientific Revolution, from about 1400 to about 1700. Craftspeople really were the scientists of their day. They were the experts in the behavior of natural materials, in synthesizing new materials out of the materials of nature. And they do enormous amounts of experimentation in order to test out these materials and then reproduce those things again and again, as we think of scientific replication.

NARRATOR: Because these craftsmen were so secretive, a basic question has long mystified historians. How did they make plate armor?

TOBY CAPWELL: Because it's difficult, mysterious and dangerous, nobody has done it. You have to get the craftsmen talking to the scientists talking to the historians, there's a lot of pieces that need to be in place.

NARRATOR: At the Art Institute of Chicago, they're trying to bring these pieces together. Curator Jonathan Tavares has asked armor maker Jeff Wasson to join a team of craftsmen trying to build medieval armor from scratch.

JONATHAN TAVARES: For me, as that young boy obsessed with arms and armor, I was always fascinated. How were these things made? I have to see it for myself, and I know I'm not the only one who wants to see this.

NARRATOR: Jeff will try to reproduce one of the best pieces in the Institute's collection: this 16th-century armor. If all goes well, he'll test what he's made to see how it stands up to the newest weapons of the day, guns.

This armor was created in a royal workshop founded by the infamous King of England, Henry VIII. Henry idealized knights, and he cloaked himself in the age old-legend of King Arthur and his Round Table.

KEITH DOWEN: Henry VIII had his own image painted onto the table at Winchester, in place of that of King Arthur, i.e., announcing himself as the new King Arthur.

NARRATOR: And he turned to armor to bring him even greater status.

TOBY CAPWELL: Henry, when he came to the throne, he didn't have an armor workshop, and he needed something that would express his own personal taste and style as a knight, as a warrior and as a king.

NARRATOR: England's biggest rivals in the 16th century were France and Spain. To keep up with his competition, Henry founded the Royal Greenwich Workshop in 1515. Carried forward by his successor, Queen Elizabeth, it produced only a few hundred armors in its century of existence, but they were some of the best ever made.

ALAN WILLIAMS: These armors were very much Rolls-Royce's of the day.

RIC FURRER: It's like an Armani suit that protects you. They had this give and take between what was stylish, what was protective and what was, ultimately, practical.

NARRATOR: Henry built the workshop alongside his palace at Greenwich, but today it's gone without a trace.

TOBY CAPWELL: There's no plaque, there's no foundations of buildings, there's nothing that would give you any clue of what went on there.

NARRATOR: The techniques for producing plate armor had been lost before. The Greeks and Romans knew how make it, but their knowledge largely disappeared with the fall of Rome, in the fifth century. This was the beginning of the Dark Ages, when Europe splintered into feudal realms and much technology was lost.

PAMELA SMITH: To produce complex kinds of material things you have to have the infrastructure. Western Europe, at this time, was really a backwater in terms of technology.

NARRATOR: For most of their existence instead of plate armor, European knights wore a type of protection called "mail" that was made of countless intersecting metal rings. But it had its vulnerabilities.

ANDY DEANE (The Royal Armouries, United Kingdom): Mail has been around since antiquity, thousands of years. It's been perfectly adequate. In many ways, it was the ultimate protection for this: slashing, cutting attacks. Slashing, cutting attacks do nothing if you got the mail and the padding. So, you change the direction of attack from that wide surface area to a tiny, tiny surface area like this, and the metal's just as effective, but you just bring it down two millimeters and there is no metal.

NARRATOR: While its mesh structure also didn't stop the impact of bludgeoning blows, mail did provide some protection against projectiles. But a technological advance in the 1300s helped change everything. With the steel crossbow, the strength of a man's arm no longer limited how far and fast an arrow could fly, thanks to a mechanical crank.

ANDY DEANE: What we have here is a "cranequin." Very simple: bring it up, slide it down, then you get your jaws, get a little bit of tension and you start cranking it up. Any idiot could use it, as long as they knew which way to point.

NARRATOR: These crossbows were up to seven times more powerful than hand-drawn weapons.

PAMELA SMITH: People were getting killed by new kinds of technology, and armor, made with much more continuous metal than chain mail, was really necessary to win wars.

TOBY CAPWELL: All the way through the 13th, 14th centuries, the story of armor development is the story of: how do we cover large parts of the human body with metal plates, when we can only smelt pieces of iron that are about as big as a softball?

NARRATOR: How to make large pieces of steel is a puzzle the armor-making team will need to solve again today.

RIC FURRER: Arnhill, get your body over here. David, we need you. Let's walk it all the way over here. We're going all the way to the downside.

NARRATOR: In northern Wisconsin, master metalsmith Ric Furrer is trying to rediscover this lost art. He and his team are tasked with forging large enough pieces of steel to make into armor.

RIC FURRER: When you start looking at the technology behind armor as a whole, and start asking the questions of, "How did they actually do this?" There aren't many easy answers. Nobody has started with dirt, you know, with raw ore and followed it all the way through to actually produce a suit of armor. We're going to do every step that was done to this suit of armor, and it hasn't been done since they were practical pieces of defense.

NARRATOR: Ric gets some clues for how to proceed from the earliest scientific metal-making book, published in 1556.

PAMELA SMITH: This book, De Re Metallica, which means "About Metals," was really the first of its kind, anywhere. What it tried to do was lay out a general theory for how metals form underneath the ground, then what human beings do when they draw those metals out of the earth. They smelt them and then they produce complex material objects.

NARRATOR: These early images provide some guidance, but the rest is mostly trial and error.

RIC FURRER: I've made a lot of metal before, by a lot of different techniques, but to make big plate like this is difficult.

NARRATOR: Ric starts by building a six-foot tall furnace called a "bloomery."

RIC FURRER: Maestro, I want you to put this in the top, you tall bastard.

NARRATOR: People have been extracting metal from rock for thousands of years. Early craftsmen learned that heating iron ore with charcoal resulted in a hard metal called steel.

RIC FURRER: Steel is an alloy, a combination of, essentially, iron with a little pinch of carbon added. So we're adding charcoal that's both our heat source and our carbon source. And then we've got iron ore, it's this crushed rock that's got iron in it. So we put it in that layered stack, and that should leave behind a nice bloom for us to forge into the plate for the armor.

NARRATOR: They pump air to feed the fire. It has to reach 2,500 degrees and run for 12 hours for the layers of iron ore and charcoal to transform into steel. For the craftsmen of the time, the science was a mystery, but this is how it works: in pure iron, the atoms are packed together like sheets of marbles, so when pushed or pulled they easily slide past each other, yielding a soft metal. But as Ric's iron ore gets very hot, the carbon from the charcoal becomes trapped between the iron atoms, making the atomic structure more rigid and changing the soft iron into harder steel.

In medieval times, some of the best iron that armorers could get came from a region in Austria called Styria, which produced 15 percent of Europe's ore.

RIC FURRER: The raw materials in Styria were all right there. They had wonderful ore, and they also had a lot of forest. So you could make charcoal. You had water in fast moving streams, so you could tap into that energy. You can see these old technologies still functioning as living history museums.

NARRATOR: Waterwheels replaced human-powered bellows. And with this virtually unlimited supply of air, furnaces could burn hotter and produce larger pieces of steel.

RIC FURRER: They were able to produce on a vast scale. We're playing catch up.

NARRATOR: Ric's fire has burned for hours, and he's ready to remove the raw steel, called a "bloom."

RIC FURRER: At the bottom, you have a bloom. It looks like a sea sponge. You have to start with a tremendous amount of bloomery material just to get the major pieces of plate, let alone all the small pieces.

MAN 1: Ready with the tongs?

MAN 2: Ready with the tongs!

MAN 1: Lock on to that.

Let me help you, Michael. Let me come in from here.

There it is. Carry it over.

NARRATOR: The bloom still has waste material, known as "slag," that could weaken the plate.

RIC FURRER: You guys ready? Gentle nudging, gentle, gentle.

NARRATOR: As they pound the metal, they drive off impurities that appear as sparks.

RIC FURRER: The breastplate weighs about 13 pounds.

That sounded nice and solid. Not a lot of slag.

To get 13 pounds of metal, you need to start with 30 pounds of bloom. As you work the bloom down, you lose material.

Out of the run we got today, we might have enough for the breastplate. But we'll sort through all of this, this after it cools, to try to scavenge every little bit that we made and do the best we can with what we've got.

Nice. So, as far as experimental archeology goes, it's a success, but we're not quite at the efficiency level of the guys in the 1500s.

NARRATOR: In Styria, water didn't only power the bellows, it drove massive hammers that flattened the bloom into plates.

RIC FURRER: How do you outfit a thousand common men or even semi-professional soldiers in protective gear? The answer is the start of mass production.

NARRATOR: Styria was a major center for the mass production of steel. At its peak, this armory, the largest of its kind in the world, it held hundreds of thousands of armors and weapons.

BETTINA HABSBURG-LOTHRINGEN (Styrian Armoury, Austria): Most of the armor we have here were produced for foot soldiers. Armor was produced in small, medium and large, so these were three possibilities you had. There were small workshops spread all over the country, where many people worked.

NARRATOR: This mass produced armor, worn by common soldiers, was a step up from mail, but by the time armorers figured out how to make these suits, in the early 1400s, a new, more powerful weapon had appeared.

DIRK BREIDING (The Philadelphia Museum of Art): This is one of the earliest types of "handgonnes." And all it is is essentially a barrel that's been mounted to a wooden shaft. A little handheld cannon, that's what it is.

NARRATOR: Developed in China, these are the first true firearms. They have no trigger. Instead, a hot poker ignites the gunpowder and propels a metal ball or other projectile.

DIRK BREIDING: Didn't score points, but it hit the target.

JONATHAN TAVARES: Better luck next time!

NARRATOR: Though these early guns were inaccurate, their power was demonstrated in the early 1400s, when pre-Protestant rebels in Eastern Europe, called "Hussites," used them to fight against the Catholic Church.

DIRK BREIDING: The earliest demonstrable power of firearms is the Hussite battle carts. They would circle into formation and then, on each cart, you had about two hand-gunners, six crossbowmen, and some with other weapons to defend the hand-gunners while they were reloading. And they defeated chivalric armies of the time in heavy armor.

NARRATOR: Guns soon swept across Europe.

DIRK BREIDING: Some of the German cities in the early 15th century were probably able to put about 2,000 men in the field with some of these firearms.

NARRATOR: Weapons became more lethal as they evolved into trigger-fired muskets. These guns were widely carried in the 16th century, when the Greenwich workshop was at its peak.

DIRK BREIDING: This is, basically, what people wearing armor were afraid of.

The barrel is a lot longer, and that allows for the full force of the combustion to go behind the musket ball and be propelled out. It gives you better velocity, better control and better range.

JONATHAN TAVARES: I'm tightening the clamp on it, which is called a "serpentine"-like a serpent or a dragon that's going to breathe fire-and ignite it, going to try it.

NARRATOR: The musket ball travels more than a thousand feet a second and can hit a target a hundred yards away.

JONATHAN TAVARES: Whoo, packs a bit of a punch.

NARRATOR: So how did armor worn by the common foot soldier stand up against the musket?

In Maryland, Jonathan has asked one of the world's leading ballistics-testing companies to answer that question. They're using a breastplate made of modern steel a-sixteenth-of-an-inch thick. It's the same thickness but made of better quality metal than what an average foot soldier would have worn at the time.

JOHN CRONIN (HP White Laboratory, Inc.): Okay, clear the range. Ready?

WESLEY MASON (HP White Laboratory, Inc.): Yes.

NARRATOR: To protect against ricochets, they'll trigger the weapon from another room.

Filmed at 20 thousand frames a second, the results are clear.

JONATHAN TAVARES: God, ugh.

NARRATOR: A foot soldier would never survive such a shot from a musket.

JONATHAN TAVARES: I can see powder burn on there. Ouch!

NARRATOR: But there was a superior class of armor available to the most elite warriors. At the Art Institute if Chicago, armorer Jeff Wasson examines pieces of armor suspected to belong to an English lord, named Compton, from Queen Elizabeth I's court. He and Jonathan look for it in a 1587 Greenwich album, a kind of sales catalogue demonstrating different styles for prospective patrons.

JEFF WASSON: By looking at the album, you can see how they were worn, what kinds of decoration that they had. So, they help complete a picture of what these armors looked like when they were worn in their time.

Lord Buckhurst and also Lord Compton. This is the one we're making.

NARRATOR: When Lord Compton ordered this armor, around 1588, England was facing a great threat. The Spanish had built the famous Armada, and the English were fearing that a land invasion would follow.

CURATORS (Wallace Collection): One, two, three, up.

NARRATOR: This piece at the Wallace Collection, in London, is one of only two complete armors in the world made in the same style as Compton's.

TOBY CAPWELL: What the designer is trying to do is give his patron options. It's an interchangeable armor system, depending on what the fighting context is expected to be.

NARRATOR: The men wearing these armors needed them for hand-to-hand combat as well as mounted warfare. Because the Spanish were well armed with muskets, a key piece was a second breastplate, called a "placard," intended to make a knight bulletproof.

JONATHAN TAVARES: The question I get time and again: "Weren't they smaller then?" There is a thought that men were a few inches shorter, but the size 5'8, 5'9 was very common in that time.

JEFF WASSON: So it's nine-and-a-half inches. And we have 10 inches here.

JONATHAN TAVARES: I'm 5' 8". It just so happens that the armor fits me.

NARRATOR: The breastplate's rounded shape had its own function. Known as a "peascod," it was mirrored in the clothing of the day.

JEFF WASSON: It would come down to the waist. It's very v-shaped. It forms sort of a ridgeline down the front of the body.

NARRATOR: Armorers knew a person wearing flat armor bore the full force of a blow, but a rounded peascod belly or helmet offered more protection, because it helped deflect a strike.

But providing protection without adding too much weight was another challenge. How did they make the armor thick enough to resist bullets, but light enough to wear?

JEFF WASSON: The downside of having a thicker breastplate or thicker armor all around is that it starts to become really ungainly to wear, so cavalry start discarding it. They'd rather be lighter and more maneuverable.

NARRATOR: The trick was to taper the metal.

JEFF WASSON: Measuring with the calipers, you can really see that. Pretty much this area, right in here, is the thickest area of the armor. As it gets towards the edges, it starts to thin out.

When we go right on the edge, it's about a sixteenth of an inch. I'm going to go in a bit.

If you want to kill someone, you'd probably want to go right in the center.

It's four times as thick, right here, so I'm very certain that it was made to deflect gunfire.

This is a little model. We have the thickness variations that we need, in order to keep it thick in the center and then thin out at the edges.

NARRATOR: To precisely craft the raw metal into bulletproof plates, Jeff brings his measurements to Ric, in Wisconsin.

Starting with a total of 30 pounds of bloom, Ric begins to flatten each piece into a slab. With every hit, impurities fly off.

RIC FURRER: There's still slag, there's still waste material, there's non-metal. As much as we can distribute it, we try to, but some of it still remains.

NARRATOR: If everything goes right, it will take about 1,000 hours to make enough plate for the entire armor. But transforming these pieces into one large, bulletproof plate will be a challenge. Ric's strategy is to weld the layers of metal together, alternating the directions of the grain, to give the whole plate added strength.

RIC FURRER: Just like wood has a growth direction, a grain, so does this bloomery material. So by forging this material out and laying one front to back and one side to side you get a stronger product in the end.

NARRATOR: These layers are visible in some knightly armors of the time that have begun to pull apart after centuries.

TOBY CAPWELL: It's not just one thick piece of steel, it's actually layers that have been hammer-welded together. So this is laminated defense.

RIC FURRER: Hit! Light, light!

NARRATOR: Then he repeatedly folds each piece to mix the steel as evenly as possible.

JEFF WASSON: I like to think of it as, like, if you're mixing bread, you first mix it and parts of it are crumbly and other parts are too wet. And so, basically, you've got to mix this metal and make sure that it gets consistent enough that it can be rolled out into a thin sheet or plate.

NARRATOR: Ric can only pound the metal when it's hot, so he reheats it over and over. But each time, he loses material.

RIC FURRER: Right around 15.

JEFF WASSON: Fifteen, okay.

RIC FURRER: I'm nervous, Ben.

NARRATOR: With only 15 pounds left, he's lost half the material. Now, the challenge is to draw out the steel to the right shape.

RIC FURRER: Let's measure it now.

JEFF WASSON: So, we only gained, only about an inch and a half.

NARRATOR: They switch to hand-held hammers to stretch the metal more gently.

JEFF WASSON: Okay, all right, keep going. Okay, all right, that's it.

NARRATOR: They've been working for days and are finally ready to see what they've wrought.

JEFF WASSON: This is what we were intending to be the top part. That it was going to be like this. We've got plenty of distance here, but we certainly don't have the sides around to what they need to be.

RIC FURRER: Sure. We need five inches more on each side, at least.

NARRATOR: After 200 hours of work, this piece of armor is no good. Ric can re-forge the metal to be used for smaller pieces of the armor, but he'll need to start a large plate from scratch.

In medieval Europe, armors weren't only produced for battle.

JOUSTING ANNOUNCER: A good strike from both of our competitors.

NARRATOR: Some of the best were designed for use in competitions. In Henry's time, as many as 10,000 spectators, commoners and nobles alike, attended events like this.

TOBY CAPWELL: Tournaments and jousts were hugely popular in Henry's court. These are fabulously expensive spectacles, but at their heart, there's still real fighting there. It's all about your icy calm, your ability to hurl yourself into combat.

NARRATOR: Tournament armors were worn for short periods of time, so they could be heavy. This one, belonging to Henry VIII, weighs 94 pounds, twice the weight of a typical battle armor. It has no gaps, anywhere.

But whether for tournaments or battle, the perfect fit was crucial.

ANDY DEANE: There is a misconception about armor that once you're in it, you can't really move. It's not true. Anything you can do out of an armor, you should be able to do in armor, so, from this bizarre position or being thrown to the ground, you should be able to haul yourself up. Obviously, not as quick-you're wearing, sort of, 70 pounds of armor-but you should be able to do it.

TOBY CAPWELL: They are engineered to follow the movements of the human body very precisely. Lumbering around, clunking around would be a danger to your knightly dignity as well as to your life. It's just not acceptable; this stuff has to move.

JEFF WASSON: All these pieces, they should be resting on each other. That's how close it's got to be. So, maybe you'd be able to fit a piece of paper underneath the plates but it's got to be really close.

So, this is the first piece that need to be fitted, articulated and put together.

NARRATOR: Back in Long Island, Jeff uses the metal from the failed breastplate to make the armor's collar and neckpieces.

JEFF WASSON: That's the amount of curve that I want to put into this plate.

NARRATOR: For these and other missing pieces, he works from templates he's made from similar armors.

Meanwhile, Ric is starting over. He's teamed with expert metal-maker Michael Pikula to figure out how to make a bigger piece of steel than last time. The answer seems simple: start with more material. But it will still take hundreds of hours of work.

Because flakes fall off every time they fire and pound the steel, they reheat it as infrequently as possible. Wide hammers help them spread the metal fast, before it cools.

RIC FURRER: Flip it please. That's all good. This is looking real good, so far.

NARRATOR: A microscopic scan shows the metal Ric and his team have made has only a few impurities. They show up as dark spots. The metal is high quality and large enough that Jeff can now shape two pieces, the breastplate and the placard that goes over it.

JEFF WASSON: So, the heat in there is about 1,800 degrees. You can tell by the glow of the metal. We're working at, like, an orange-yellow heat. And at that temperature, the metal is like clay, and it will move, move pretty well for you.

We've got to be quick, because the edge is thin.

NARRATOR: He has to make the center of the breastplate four times thicker than the edge, and at the same time, give it its distinctive shape.

JEFF WASSON: Yeah, that's really good. That's nice.

NARRATOR: After weeks of pounding and shaping, there's one final step that transforms good armor into great armor that's bulletproof: hardening the metal.

ALAN WILLIAMS: If you can work out how to harden steel, you can certainly double its strength, which means that it is then twice as resistant to bullets as well as to other weapons.

NARRATOR: There are no surviving texts from the time accurately describing how they hardened armor, but Jeff has come up with a strategy.

JEFF WASSON: All this wiring on here is bracing, to keep the piece from warping.

NARRATOR: He's going to heat treat the armor in a process known as the "quench."

JEFF WASSON: You want the metal to be tough, but if it's too hard, it'll be brittle, so if a gun or a weapon hits it, it'll crack. With the heat-treating, you're causing a change in the crystal structure of the metal.

NARRATOR: Right now, magnifying the unhardened steel reveals many light areas. These regions are low in carbon, so the iron atoms can slide past each other, making the armor too soft.

Compared to this unhardened metal, the Greenwich armor has tightly interlocking grains with carbon distributed evenly throughout. To achieve this hardness, Jeff will heat the steel, so the grid of iron atoms expands, and carbon can redistribute from high concentration areas to low ones. Then he'll lock the carbon into place by cooling the armor quickly in oil. This new structure is harder, but more brittle, too.

Heating the piece again will soften the metal slightly, so it can withstand an impact without cracking. The crystalline structure should now be more uniform and harder, like the original Greenwich armor.

JEFF WASSON: It's really extreme, going from really hot to being quenched in the oil. That's a huge shock on the metal. So the metal could warp or it could crack. It's dangerous, you know. It might not work out. It could destroy all the work I put into it so far.

Oh, yeah. We're ready.

NARRATOR: A crack could mean disaster. He listens to see how the metal reacts.

JEFF WASSON: Oof. Did you hear that?

It was making strange cracking noises, but you know what, that's just what it's going to be.

NARRATOR: Jeff can't see any cracks in the placard that protects the breastplate, but he won't know its strength until the armor is tested.

JEFF WASSON: Now on to the other, bigger one.

Yeah, that's good.

NARRATOR: This time, there's no cracking sound. The breastplate has come through unscathed.

After a polish, it's ready to compare to the Greenwich steel of the time. Though there appear to be some concentrations of soft iron, visible as white blotches, the tight crystalline structure that gives the metal its strength is remarkably similar to the original.

The quench seems to have done its job, but will the breastplate outperform the common armor and stand up to the musket?

JONATHAN TAVARES: Having just seen this, it's a little startling, you know? You see that big whopping hole. It's just, it's a little scary, you know? All this, months of work on this piece and then, you know, you just got to be a little bit nervous, that's all.

NARRATOR: Nervous for good reason.

ALAN WILLIAMS: Certainly, if you were unlucky enough to be shot at by a musketeer at short range, then nothing is going to help you. You will be killed, and that's that.

NARRATOR: Jonathan wants to know what the ballistics experts think.

JOHN CRONIN: You can't help but make assumptions sometimes, but the simple fact is, through observation, we've learned your assumptions means absolutely nothing. You have to put rounds on it to really understand what's going to happen.

WESLEY MASON: My gut tells me it's not going to penetrate.

JOHN CRONIN: It's significantly thicker armor, right? You have an air gap between the two plates, and you may have the opportunity for deflection. So, you really have a lot working to your advantage on the next shot. That doesn't mean that it will absolutely stop it.

JONATHAN TAVARES: The musket is not… This is the super-weapon of the time. It's this. The next step is getting hit by a cannon.

JOHN CRONIN: Pan's open.

JONATHAN TAVARES: Shoot.

JOHN CRONIN: Just wait a few seconds-got to let the range clear. How are you feeling?

JONATHAN TAVARES: Eh…

JOHN CRONIN: It's going to be a long 30 seconds.

WESLEY MASON: Watch them cables.

JONATHAN TAVARES: Oh, man, right through?

Nope? Wow, it held up, held up pretty good, actually. Oh, wow! There's just a dent, just a little bigger than my thumb.

NARRATOR: Even for modern ballistics experts, the armor has performed beyond expectation.

JOHN CRONIN: Look at that. The whole system, everything that we've looked at has been impressive, everything from the firearm all the way through to the breastplate. I think they have all performed incredibly well.

JONATHAN TAVARES: Whoa, the bullet is gone. Armor: 1-bullet: nothing.

NARRATOR: At 20,000 frames-a-second, they can see the musket ball disintegrate upon impact.

WESLEY MASON: See how the curvature deflected it away?

JONATHAN TAVARES: Yeah, yeah. Goes to show you the peascod belly is not just fashion, it's function.

NARRATOR: There's barely a dent on the breastplate.

JONATHAN TAVARES: You can just tell where it happened, that's it.

JOHN CRONIN: I mean there's no question about it. This is something where the soldier wearing this armor gets to go home.

JONATHAN TAVARES: Yes, you could stand down a musket at pretty close range. But how many people could afford this, you know? Not many people could afford this. This is the few and far between.

NARRATOR: The successful test fuels Jonathan's passion to complete the armor.

JONATHAN TAVARES: Gilding and etching and completion…and then wearing.

NARRATOR: The elite knights who wore these armors wanted more than just protection; they wanted to be covered in gold.

TOBY CAPWELL: As soon as you add gold, you make a statement about the knightly rank of the wearer. This one with this amount of decoration is a major step up in the social and economic pecking order.

NARRATOR: Adding gold was an expensive and involved process, and the team has to rediscover how the Greenwich armorers pulled it off.

As a first step, Jonathan has asked Catherine Winings of the School of the Art Institute of Chicago to copy the pattern that will be etched into the metal.

Using a picture of the original armor, she paints Jeff's completed neckpieces. It's believed the Greenwich craftsmen used oil and lead paint to protect the surface of the armor from an acid that would eat away at the surrounding metal. The lines she's painting will be replaced by gold.

CATHERINE WININGS (School of the Art Institute of Chicago): For me, probably the most difficult are these little swirly things inside, because I'm trying to imitate the marks of the person who was doing it originally, so I have to try to think the way they would and adjust my marks accordingly.

NARRATOR: The next step will be to apply the acid that will eat away any place that isn't protected by paint. The intricate pattern left behind will be embellished by gold.

JONATHAN TAVARES: It's meant to be fashionable. It's meant to mimic, almost, like, the embroidery on your civilian clothing.

NARRATOR: Jonathan is using a technique from a 1531 book describing how the craftsmen likely etched their armor.

JONATHAN TAVARES: We had this "aha" moment, but what were the chemicals used? How do we understand this?

NARRATOR: A chemical historian identified the ingredients as a mixture of salt, vinegar and copper sulfate, like root killer. This makes an acid paste that Jonathan hopes will eat through the metal.

JONATHAN TAVARES: One of the biggest revelations is that it wasn't submerging a plate into a bath of acid; it was using a paste and smearing that over the selected areas that you're hoping to etch.

Like icing a cake.

The painted layer held up really well.

NARRATOR: He'll apply the acid again and scrub off the paint. Then the neckpiece, which has turned red in a chemical reaction, is ready to be covered in gold.

DIRK MEYER (Craftsman): (Translated from German) You roll the gold very flat and thin.

NARRATOR: The gilding itself takes place in Germany, where Dirk Meyer is one of a handful of craftsmen in the world who have mastered this medieval technique.

Because gold doesn't bond easily to steel, getting it to stick requires many steps, including mixing the gold with toxic mercury, then painting it on.

Now the most dangerous step, burning off the mercury. He works under a protective hood, because the fumes can cause brain damage.

TOBY CAPWELL: They didn't care about safety. They didn't really understand the dangers fully.

JEFF WASSON: In the 19th century, hatters would use mercury to make felt hats. They would be breathing those fumes. And that's where that term "mad as a hatter" comes from, because they all went crazy.

NARRATOR: The gilded piece is sent back to Jeff, in Long Island.

JEFF WASSON: Wow, that is really fantastic. It just takes the piece to a whole new level.

NARRATOR: But there's still one more mystery to solve.

In the only known painting of Lord Compton, the armor is blue, which squares with evidence found on the original at the Art Institute of Chicago.

JONATHAN TAVARES: We found little dents around old rivets where the old blue finish was not completely scoured away.

NARRATOR: Jonathan believes blacksmiths heat-treated the armor until it was bright blue.

JONATHAN TAVARES: When you look at these armors, they're magnificent in the museum, but they are hundreds of years old, and they've been through a lot. We're bringing one to life, and we're going to see what it really looks like, you know, like when it was new. And that's going to be really exciting.

NARRATOR: Jeff will essentially have to rust his masterpiece by heating it to just the right temperature.

JEFF WASSON: It's what's called an oxide. An oxidation is rust where the oxygen in the atmosphere is reacting with the metal and creating a deposit. With the heat, you are causing this oxidation to happen, and it creates these colors.

NARRATOR: Instead of the red we associate with rust, heat shifts the color toward the blue part of the spectrum.

He checks the armor many times over half an hour, until he thinks the color is just where he wants it.

JEFF WASSON: Just let it sit for a moment.

All right, really close.

Wow, that's looking really good.

NARRATOR: Finally, it's perfect. After more than a year of work, the riddle of how the Greenwich armorers made these bulletproof masterpieces has been solved.

JONATHAN TAVARES: I can't believe this. This is like holding the original. Well done, Jeff.

NARRATOR: Lord Compton's armor was completed around 1588, but within a few years, the knight in shining armor was receding into history.

KEITH DOWEN: The image of the knight in shining armor is a very romantic one and a very powerful one. However, in reality, full armor was only worn on the battlefield for roughly a period of 200 years.

NARRATOR: By the late 16th century, warfare was modernizing with the rise of guns and larger, more centralized governments, and knights were left behind.

PAMELA SMITH: Within this new social formation, knights became really obsolete, as you had a military that a central government or a central king could put into force.

JONATHAN TAVARES: As you get closer to the 1600s, firearms completely take over and there's this slow evolution to where you use less and less armor.

Whoa, oh, my gosh, Jeff. I can't believe that.

JEFF WASSON: It's amazing right? Really incredible.

JONATHAN TAVARES: I don't believe I'm staring at me.

JEFF WASSON: It's gorgeous.

TOBY CAPWELL: In the middle of the 17th century, you no longer have aristocratic heavy cavalry in full plate armor anymore. They started to be referred to as "the lobsters" because they were these outlandish creatures that were already, then, like something kind of out of a storybook.

NARRATOR: It was the sunset of one technology and the dawn of a new one, but for a brief moment, ingenious craftsmen helped keep the knight in shining armor alive.