-In the rich recorded history of Great Britain, one period is shrouded in mystery and clouded by myth.

After an occupation lasting nearly 400 years, in 410 AD, the Roman army abandoned the island.

History holds that Britain then plunged into two centuries of turmoil and violence... known as the Dark Ages.

Legends tell of a great leader who unites the lawless land to fight off an invading horde -- King Arthur.

But how much truth is there to the story?

♪♪ Now, new archaeological discoveries are rewriting this chapter in Britain's history.

-It's really clear!

-With exclusive access to unprecedented new finds... -When you look at their bones, you find a very, very low incidence of weapon injury, sword cuts.

-...and using groundbreaking science... -It was one of those total wow moments.

-...Professor Alice Roberts pieces together the real story... -It's just absolutely phenomenal.

We've got continuous occupation all along this strip which is immense.

-...to reveal how 5th and 6th century Britain was anything but dark.

-We're not looking at an abandoned landscape of desperate poverty.

-It's not necessarily the truth.

-It's about as far removed from history as you can get.

-Modern archaeology could finally uncover the true story of King Arthur's Lost Kingdom.

♪♪ ♪♪ -In 410 AD, Britain suffered a political catastrophe.

The Roman Empire that covered most of Western Europe had become over-stretched, weakened by infighting and external attacks.

After 400 years of prosperity, the Roman aristocracy, troops and bureaucrats left the island.

♪♪ -Dies tenebrosa sicut nox.

It's a brilliant, evocative way of saying "Welcome to the Dark Ages."

-The common belief is that the Roman departure had a devastating impact across Britain.

Without Roman authority, society collapses.

The roads and towns fall into ruin.

Civilization crumbles.

The era after Roman rule became known as the Dark Ages.

But the truth is, almost nothing is known about what life was really like.

-For the period 400 to 600 -- that's 200 years, that's 8, 10 generations -- we know the names of... you can kind of count them on two hands.

For the whole of the period 400 to 600, in the British Isles we have 2 or 3 people whose writing we have fragments of.

-In the absence of recorded history, stories about one powerful leader became popular -- The great King Arthur.

But what truth, if any, lies behind the legend?

What was 5th-century Britain really like?

Professor Alice Roberts, an expert in archaeology and human remains, wants to separate fact from fiction using scientific discoveries- and find out what really happened at this pivotal moment in history.

♪♪ Her journey to uncover the truth about King Arthur's Britain begins at the British Library in London.

She's meeting Julian Harrison, the Curator of Medieval Manuscripts.

-So this is Geoffrey.

-Here we have one of the earliest copies of Geoffrey of Monmouth's "History of the Kings of Britain."

-It's a copy of a 12th-century bestseller.

The writing on the animal-skin parchment is still crystal clear.

-The script is so beautiful.

It's so regular.

That's fantastic.

-900 years ago, a Welsh monk, Geoffrey of Monmouth, wrote his own account of the history of Britain.

His chronicle told of a King Arthur who ruled 600 years before Geoffrey's time.

-Here we are.

Here's the page I want to show you.

-Geoffrey's manuscript is in Latin, the written language of medieval Britain.

-I can recognize the odd word here.

I can see concept and then "eadem nocte."

-" Eadem nocte."

So, this tells you that on this night, "eadem nocte," was conceived, celebrated, King Arthur, "Arturus," "Arturum."

-According to Geoffrey, the mythical king has a rather bizarre conception.

Arthur's father asked the wizard Merlin to cast a spell to disguise him as the Duke of Cornwall, so he could seduce the Duke's wife.

-He's in the appearance of her husband and he satisfies himself, and as a result on that particular night, on that particular occasion Arthur was conceived.

-That moment as those words appear on the page, that's the beginning of King Arthur as we know him.

♪♪ -A remote rocky outcrop called Tintagel in the far west of Britain is where Arthur's story begins.

-It's in the top line there.

-That looks like "dece" to me.

-It says "dei" and then there's a new word.

-Tin-ta-gol.

-"Tintagol."

Exactly.

-Is this the first association of Tintagel as a place with Arthur?

-It is indeed.

-Packed with sex and violence, Geoffrey's account unfolds like a modern-day action movie.

-It's full of excitement, it's full of horror, it's full of lots of things that an audience would love.

-And eager to please his Christian audience, Geoffrey came up with the perfect bad guys.

With the Romans gone, the ancient Britons are vulnerable to attack.

In Geoffrey's retelling, pagan tribes known as the Angles and the Saxons swarm in from modern-day Holland, Germany and Denmark.

Their armies invade the east coast of Great Britain, destroying everything in their path.

-I suppose he gives us this idea today that the Romans abandoned Britain to its fate and when the Romans go it is just chaos.

There's plagues, there's civil war, there's the Saxons just slaughtering everybody.

So it's real blood and thunder stuff.

-But according to Geoffrey, Arthur comes out of the West, unites the Britons, and leads the counter attack.

The result is a split country.

Embattled Britons in the west and in the east, new Angle and Saxon hordes, that later historians combine into a single entity -- the Anglo-Saxons.

This is King Arthur's Britain.

-In his account to simplify it, yes, you get, you get this sense of the Britons are the ones who are defending everything that is right and good.

You get this sort of frontier line between these two constantly warring factions.

It is "us against them."

It is Britons against the Anglo-Saxons.

The Anglo-Saxons are the forces of evil that need to be destroyed.

Britons and Saxons are killing one another, and that's Arthur's world, that is where he existed.

-Here it talks about his sword, "g ladio optimo."

-The best sword.

-And that was called Caliburno.

-Caliburn-- Is that Excalibur?

-This is Excalibur.

-Yes!

-But in the original it was called Caliburn.

-Arthur's sword is a weapon of mass destruction.

-It tells you that with Caliburn alone, Arthur killed some 470 men single-handedly.

He went berserk, essentially.

-470 victims in a single rush.

I mean that is -- it's too extraordinary to believe, obviously.

I mean, he's being portrayed here as... -He's a superhero essentially.

-Yeah, yeah.

-Geoffrey's book is the first reference to a King Arthur that we have.

Earlier accounts written closer to the Dark Ages don't mention a king named Arthur, but they do describe a violent invasion.

The earliest description was written by a monk named Gildas.

A few fragments of his text are still legible.

-He's writing in the 6th century.

And he isn't writing so much a work of history.

It's more a polemical text, criticizing the Britons and blaming their evil ways, their bad ways of living with that's why they were conquered by the Saxons.

This is one of the few passages we can still read now but he talks about the -- like ravishing wolves.

The Saxons are loopy.

-Loopy yeah.

-They are obviously destroying.

In Gildas' terminology, they are destroying everything in their wake.

-So, again this is a, this is an invading force.

This is the arrival of the enemy essentially.

-Precisely.

-And the difficulty with these kind of accounts I think is that, is that you're almost getting a single view of how this happened.

-Both Geoffrey and Gildas's histories are highly subjective, making it difficult to take them at face value.

They can't be trusted as fact, but they have given Professor Roberts something specific to investigate.

They both describe a massive invasion from the east and the native Britons resisting in the west.

And the archaeological evidence supports this idea -- Anglo-Saxon artifacts have primarily been found in eastern Britain.

If great wars were fought, evidence of mass slaughter and conflict should lie along this frontier line of their supposed occupation.

Archaeologist Dominic Powlesland has been flying, digging and mapping a vast area on the eastern side of this imagined border, near the village of West Heslerton in Yorkshire.

-Clear prop.

Okay, ready Dominic?

-Yeah, I'm ready.

-Right, hold on tight here we go.

Golf-Romeo-Romeo rolling.

-Will Dominic's research confirm the written accounts of a full-scale foreign invasion?

-These fields underneath us are entirely filled with archaeology.

There's archaeology in every single one.

-Dominic uses modern technology to map every single artifact relating to the Anglo-Saxons found over 25 square miles of what is today farmland.

It's taken an army of volunteers 40 years to complete their survey.

-We've surveyed all these fields.

-Roberts is here to find out what the hard work reveals about life on the alleged frontier of King Arthur's Britain.

Key to the process is geophysical surveying -- a technique that uses ground-penetrating radar to map traces of ancient structures.

-So, every single spot here is a feature?

-Yeah.

So, all those dots are individual features.

You can zoom in to this area here.

-Click on that we get all the finds information.

-Oh, wow!

-That's the plan, this is the distribution of finds within it.

-It just goes on and on!

You've got thousands of finds coming out of every single one of these features, and hundreds of these features.

I mean, that's a phenomenal amount of data.

-Yeah.

About a million finds altogether.

-What Dominic has found is extraordinary.

But even more amazing is what he hasn't found.

There are no mass graves of defeated warriors.

No signs of battle or conquest... anywhere.

There is no evidence here for mass slaughter of local Britons by violent Angle and Saxon tribes.

-I have never seen any evidence of an invasion.

♪♪ -And the Anglo-Saxon skeletons show few signs of violence.

-Once you start killing people in large numbers they leave themselves lying around, you can't avoid them.

So, we don't see lots of Anglo-Saxons with massive injuries.

-When you look at their bones you find a very, very low incidence of weapon injuries, sword cuts.

This is a society that is playing with the idea of a military world, but doesn't actually seem to be engaging with physical conflict to a huge degree.

-And the findings here are backed up elsewhere.

-Here's a very, very good piece of science -- of all the dead bodies dug up that may belong to the period 400 to 600 -- and we have thousands of them -- men and women, children, old people, young people.

But of all those thousands of bodies, if you ask the number of those bodies that have sharp-edge weapon injuries, it's less than two percent.

Where do battles fit into that?

-The archaeology makes it very clear -- there was no large-scale conflict.

It's a stark departure from Geoffrey and Gildas's written accounts -- the idea of native Britons fighting the invading Angles and Saxons doesn't reflect what's being found on the ground.

Instead, the archaeology reveals exactly what the Angles and Saxons who came to Britain were doing.

Dominic has pulled together all the data in what he calls The Wallpaper.

-It's just phenomenal because all of that work comes together to give you a picture of a landscape which is so densely settled.

-Yeah.

-The Anglo-Saxons weren't blood-thirsty warriors.

They were farmers.

-We've got settlements here.

There's one here.

There's one here.

There, of course there's this large one at West Heslerton.

We've identified 14, probably now 15 settlements.

-Anglo-Saxon buildings dominated the landscape.

The settlers imported their traditional, northern European building style.

Structures were built in wood with thatch roofs -- a style known as Grubenhauser.

-So, these blobs here are the Grubenhauser.

-All of these little blobs?

-You see big houses there, big houses here, and lots of these Grubenhauser.

You will also see this hamlet here, a hamlet there, a load of buildings there, a load here.

You see -- it's all joined up.

There's stuff everywhere.

-In the Anglo-Saxon period, this area was densely settled -- hundreds of buildings in more than a dozen separate communities.

♪♪ -Roger Lima.

Standby to land.

-I think that might be Alice down there.

-Dominic's meticulous research tells a very different story from the common understanding of a violent invasion.

♪♪ -Bit of a bumpy landing there.

-That's okay.

-Are you all right?

-Yeah, I'm fine.

-The picture that's emerging in the east is of a peaceful society, not a violent one.

But what about in the west?

Will archaeologists find any evidence of either violent conflict or a legendary king on this side of Britons' Dark Age Divide?

Professor Roberts has access to a new excavation on the far west coast of Britain.

♪♪ -And it's at Tintagel, the very site where, according to Geoffrey of Monmouth, Arthur is supposed to have been conceived.

♪♪ ♪♪ A major archaeological dig is underway here, on a part of the island that has never been excavated before.

♪♪ Archaeologist Win Scutt is the site's curator.

-So, Win, introduce me to Tintagel from the air then.

What are we looking at?

-Well, it's fantastic, you can already see one of the rectangular buildings that dates to the 5th, 6th Century.

-So, this is the period you're specifically interested in here.

-Absolutely, yes.

-In contrast to the wood and thatch buildings in the east, there were more than 100 stone buildings here.

-Is that more?

-Some more over there, absolutely.

It's a settlement of hundreds of people.

-These simple dwellings were first excavated more than 80 years ago.

But in the summer of 2017, a much grander complex was discovered.

-We're excavating behind these cliffs on -- these are the Southern cliffs and there we are, it's coming into view.

-Oh, there are the trenches.

-There are the trenches.

Fantastic, yes.

-And they're at work.

We can spy on them.

That's brilliant.

-Really exciting.

-With only five weeks to dig, the archaeologists rush to gather all the evidence needed to create a detailed portrait of life in the 5th century.

Alice joins site director Jacky Novakowski to understand the significance of the new excavation.

-Once we started taking off the turf, the stone walls started to appear quite quickly.

So, it's been buried over 1,400 years ago and now we are uncovering it for the first time.

-They look very different to me, to the remains of the buildings that I have seen on the eastern side, which again are fifth, sixth century but much smaller stones and much thinner walls.

-They're completely different in terms of build character and the amount of sheer investment that has gone into their build.

I mean, they are substantial.

-Well-built walls, aren't they?

-Yeah, they're extraordinary.

They are over a meter wide, and you can see that they are made of large blocks of slate.

Very blocky material and you've got them laid horizontally forming a really nice coursed wall.

-These buildings were built to impress, I think.

And they're part of this larger complex of other buildings that go off in that direction, and in that direction, so you can see we've got our work cut out.

-The team's findings will be used to create a 3D model of this apparent 5th-century citadel... bringing Tintagel out of the Dark Ages and back to life.

The buildings occupy a natural terrace with a stunning vista.

Their prominent position, substantial size and thick walls indicate a great deal of time and effort was taken in their construction.

There are strong hints that whoever lived here was someone important.

These people weren't farmers like in the east of Britain.

-They do look like they're high status.

This isn't people eking out an existence up here on top of Tintagel.

This is people living well.

-This is people living very well, I think.

A lot more care has gone into the construction of these buildings.

We're working on the idea that these buildings are probably residences, high-status residences.

It's all got the feel of an extraordinary large settlement.

Which is maybe the place where the most powerful person who is living in this area was resident at the time.

-A powerful Dark Ages leader perhaps, but it's still a huge leap to say that it could be King Arthur.

In fact, no one has ever found any proof of the legendary leader's existence, let alone whether he lived at Tintagel.

Just like in the east, the team is unearthing evidence of a peaceful lifestyle.

But it's a much, much more extravagant one.

-That's a good piece.

-Ah, nice.

That is a nice high-quality piece of tableware I'd guess.

There's a rim on the bottom.

That's sat on the table.

Beautiful.

-We've been finding a lot of the fine tablewares.

And even some of the dinner plates, and the storage vessels containing the wine and olive oil are being broken and just discarded around here.

-Whoever lived here was rich.

This is the biggest hoard of this type of high-value pottery dating from the Dark Ages that's ever been found in Britain.

-That is really beautiful.

-And there are even pieces of fine glassware for drinking wine.

♪♪ The artifacts being unearthed at Tintagel are completely different from the Anglo-Saxon ones found all over the eastern side of the country.

In this sense at least, the archaeological evidence and historical accounts are matching up.

5th-century Britain does seem to be a very divided country.

But divided by culture, not violence.

But what happened to the Britons in the eastern half of the country if the Saxons and Angles did not invade or conquer?

In the last decade, more than 100 skeletons have been unearthed in an Anglo-Saxon cemetery in the eastern half of Britain.

And with them, some important new clues.

♪♪ The remains of one of the female skeletons give Professor Roberts a better understanding of everyday 5th-century life.

-My first impressions looking at this skeleton is that this is somebody who was quite gracile, quite slightly built.

I'm looking at these teeth really carefully.

If I look at the molars, she's quite clearly a young woman.

The third molar, the wisdom tooth, comes through 18 to 21 years, and there's just a little bit of wear on that, But then if you look at the front teeth it's completely different.

The enamel has been completely worn away and they're flat on the surface.

So that suggests she's doing something with her front teeth, which isn't just about food processing.

So perhaps using her teeth as a tool, maybe leather working.

Definite use of the teeth just there.

-A fascinating glimpse of life and work in the Dark Ages.

But it's the objects found with her and other skeletons that provide fresh insight.

Alice meets lead investigator Duncan Sayer.

-So, we've got an adult in the middle with two brooches on her shoulder and a load of amber beads.

And next to her is an adolescent.

And we have a child.

-Yes, a small child.

-Small child, yeah.

-It makes you wonder happened, how they ended up in the same grave.

-Well, it does doesn't it?

We've got round brooches and we've got long brooches, we've got cruciform brooches.

We've got all the works really.

-All what you'd expect from an Anglo-Saxon cemetery.

No surprises there.

-No surprises.

Absolutely typical in every way.

-The grave goods suggest these people were part of the newly arrived Anglo-Saxon group.

But archaeological evidence, just like written history, is open to misinterpretation.

So Duncan is using high-energy physics to examine one of the brooches in greater detail.

♪♪ Here at the UK's national facility for synchrotron radiation, a beam of electrons is accelerated almost to the speed of light as it travels around a 600-yard loop.

♪♪ As the electrons move, they throw off intensely-focused X-ray beams that allow for compositional data gathering.

The X-rays let Duncan probe the chemical make-up of a tiny part of the brooch.

♪♪ ♪♪ The results are unexpected.

-Okay.

So, do the blue areas and green areas represent different elements?

-Exactly.

The green bits highlight iron, and the blue bits highlight lead.

The lead tells us that this is glass.

-It's a style of glass work that's been seen before... typical of Britons, not the Angles or Saxons.

The brooch was made locally, not imported.

-What you're doing is you're taking out a glass, grinding it up, and grinding into it the scrapings from the inside of a crucible.

And then you bake it into the holes into the object and it makes enamel.

-Enamel like this was a specifically British production technique.

So although the style of the brooch is typical of continental Angle and Saxon tribes, it's either been made by British hands or by someone who learned from a local.

-So, this is fascinating, because it means that this is not an import from the continent.

It's an imported idea, it's an imported style, but it's a locally made object.

-Exactly.

-What appears to be jewelry imported from Europe was more likely made in Britain.

The results suggest assumptions that these are all Anglo-Saxon skeletons might be wrong.

Something more complicated is going on.

The team needs a way to identify the skeletons scientifically, so they turn to another modern technology -- DNA analysis.

Skeleton 82's DNA is a close match to the DNA found in today's Dutch citizens... She's genetically Anglo-Saxon.

But Skeleton 1 is genetically indigenous -- a match with ancient Britons.

Skeleton 96 is an even bigger surprise -- a hybrid of British and Anglo-Saxon ancestry.

It's a very small sample, but it suggests the Angles and Saxons who arrived from northern Europe didn't suddenly replace the Britons in the east -- they mixed with them.

-People would probably not have thought of themselves as Britons or Anglo-Saxons.

They would probably have thought of themselves in a much more local way than that.

-This is not a period when people would have known that they were members of a particular nation state.

Nation states didn't exist, people didn't have passports, they weren't citizens of one country or another.

-The story of Arthur defending the ancient Britons against an invading army is likely a myth.

Despite Geoffrey and Gildas's accounts, the archaeology shows the Anglo Saxons didn't arrive overnight en masse.

Instead, it was a slow and gradual process, probably over a very long period of time, not murdering the locals, but merging with them.

-There are people coming across the North Sea.

But they're not entirely replacing the group that are here.

They're bringing new styles, new ideas, new ways of talking, new religions which are adding to the mix that's already here.

-It's not a full-scale, you know, replacement of one culture by another.

-Over time, people are trading, intermarrying, even swapping fashions.

-We're seeing Britons adopting Saxon-style brooches.

We're seeing Saxons adopting Roman-style brooches.

-These things wouldn't have been in these very clear-cut identities that we ascribe to today.

It would have been much, much more complex than that.

-Eastern Britain is trading with the Germanic world, with the Saxon world, with Scandinavia.

That's where their fashions, that's where their trade is being connected to.

-Given their geographical proximity, it makes sense that Northern Europeans would have formed connections with Britons in the east rather than the west.

This is a radical new understanding of life after the Romans left Britain.

Far from being conquered, the native Britons in the eastern half of the country seem to have absorbed the incoming Northern Europeans.

It was a time of trade and integration.

But in terms of daily life, little changed.

-I suppose if you think of a sense like if you take America as an example you've got African-Americans, Italian-Americans.

People are adding things to the various pot that is America.

That's what happening in, in Britain in the 5th and 6th century.

-And proof of the true story of the Dark Ages can be found today in modern Britain's DNA.

Researchers at the University of Oxford have collected thousands of DNA samples from people across Britain whose families have lived in the same area for generations.

-We tried to focus on individuals, all of whose grandparents were born in the same area.

So in that sense their DNA had been there at least for two generations and probably quite a long time before that.

-Peter Donnelly's work maps regional variations in British people's genetics in greater detail than ever before.

Alice wants to understand what modern genetics can reveal about Britain's past.

-So, what do we see on this map then?

What do the different colors and different shapes represent?

-So each circle or square or or triangle represents one of the 2,000 individuals we sampled.

And then the combination of color and shape represents a genetic group.

There's a group represented here in pink squares that's one of the genetic groups we saw.

There's another group in blue circles.

There's a large group across much of central and southern England, groups in, in South Wales and North Wales and so on as, as we look through the country.

-And what I find utterly extraordinary about it is you've got all of these different colored clusters, which do seem to be quite localized, and I would just have expected the whole thing to be much more homogeneous.

-It was one of those total wow moments that we don't have too often in our career, but it was really exciting.

-At first, it looks like the genetic map supports the historical accounts of Anglo-Saxons decimating the local population.

-Do you think this pattern of red squares is explained by a massive Anglo-Saxon invasion, replacing everything that was there before?

-That's absolutely not the case.

What's interesting is if you take a typical person in Central and Southern England, that accounts for about 10% of their DNA.

So, we do see evidence of the Anglo-Saxon migration, I think clear evidence of that.

But it certainly wasn't the case that they replaced existing populations.

They contributed to the DNA of modern English people but in the minority of the DNA that's there now.

-The surprise is that Anglo-Saxon DNA has contributed only around 10 percent of the genetic variation.

-What's very clear is that most of the DNA that's carried by someone in Central and Southern England now is DNA that was there before the Saxons arrived.

Not only did they not replace the existing populations, they mixed with them, but they're a relatively small proportion of the ancestry of the people now have.

-Even though the archaeological record now suggests differently, the Anglo-Saxon invasion story still fills the history books, and Anglo-Saxon ideas shaped British culture, not least by inspiring the English language that's spoken all over the world today.

But despite popular belief, the genetics indicate Anglo-Saxon immigrants probably never outnumbered the native Britons.

-Historians and archaeologists have argued for decades if not centuries over whether the appearance of a new culture really means that a whole load of new people came in.

And we've actually never been able to resolve that question and now we're starting to be able to do that.

-What's interesting about genetics is it, by definition it's reflecting what happened to the masses.

Whereas often some of those other sources are colored by the successful elites who impose languages or impose political systems.

-In the east, the native British and Anglo-Saxon people merged on a large scale.

♪♪ But what about the west?

Why does Tintagel seem so wealthy in comparison?

And why is King Arthur so strongly connected to the site?

This is Fort Cumberland, the home of Historic England's Archaeology labs.

Many of the finds from Tintagel are analyzed here.

♪♪ The fort is a scientific production line, turning excavation into information.

♪♪ From the new site at Tintagel, 130 gallons of soil filter through the flotation tanks.

The experts can finally separate the Arthur legend from archaeological fact.

Alice has come to meet pottery specialist Maria Duggan.

She is one of the experts examining the unprecedented haul of pottery shards unearthed at Tintagel... and looking for clues about the lives and identity of the people who lived there.

-So, this is our really characteristic fine-ware form for that late 5th Century, early 6th Century.

And we've got about 14 vessels of the same form.

All slightly different.

-So, that's a bowl is it?

-Yeah, it's a big dish.

So it's actually quite big, it's probably about 30 centimeters.

-The distinctive shape indicates the bowl was not made locally.

-So that's coming from Turkey?

-Sort of Western Turkey.

-Yes, yeah.

-It's come a long way.

-This fragment of pottery connects Tintagel to what would then have been Byzantium in the Eastern Roman Empire.

There are hundreds of pieces to examine.

-The vast majority of the finds are amphorae, so they're storage vessels for transport of wine or olive oil, things like that.

Also other fine wares.

So we've got some North African material.

And also, from southwest France so from the Bordeaux region.

-Right.

So, it's coming in from all over the place.

-Yeah.

-When you find a blooming great sherd of Roman amphorae, and not just one sherd of amphorae, but buckets of the stuff, that tells you that there's trade and diplomacy and interaction and people are moving across the European landscape and seascape.

-These artifacts demonstrate that the Mediterranean and the Atlantic coasts were incredibly well connected to Tintagel.

-Tintagel is producing evidence that's showing us how active those trade routes were in the -- the 5th and 6th centuries, that you do have this material that's coming up from the Mediterranean up the Atlantic Coast and is clearly being valued and perhaps traded up that Atlantic seaboard.

-While eastern Britain interacted with northern Europe, western Britain traded with Byzantium in the Mediterranean.

Tintagel was clearly an important international port of call.

So, what would it have looked like in its heyday?

-Yeah.

-Co-director of the site, James Gossip, has made a detailed architectural survey of the dig.

-Okay.

Can we have a spot height on the hearth, Martin?

-Combining measurements with thousands of photographs creates a perfect virtual record of the new site.

-So, this is towards the sea, isn't it?

-Yup.

You can really see how the buildings are part of a planned design, with shared spaces.

-The complex is laid out over upper and lower terraces.

The upper building has a 32-foot room with a 16-foot side-room.

There's a smaller building next door and a large open courtyard -- all connected by a central path.

-What you can see is a series of steps leading up into this opening in our upper building, connecting the building with the trackway that runs between the two terraces.

-An area of carefully-laid stone floor strongly suggests some rooms may have had a special function.

-It's a really nicely laid surface of fairly thin slates.

What's noticeable about that is how fragile and delicate it was.

When we walked on it, we noticed that, you know, some of the slates might break pretty easily.

-You do wear big boots though, to be fair.

-True, but I tried it out in bare feet as well.

-Unlike the well-worn floors in the rest of the settlement, this section is much more delicate and in pristine condition.

-That suggests that perhaps it's, it's a really quite special floor.

Perhaps it was a space that wasn't really designed to be walked on very often.

What that means about the function of the building we don't really know.

-But I suppose it suggests that it's not an ordinary domestic dwelling.

♪♪ -This new data helps generate the first 3D model of the entire Tintagel site.

The complex may not look opulent to modern eyes, but to Dark Age visitors, it would have felt palatial.

It's among the most substantial post-Roman buildings found in southwest Britain... ...and a complete departure from how we thought people were living at the time.

♪♪ But people weren't just sailing to Tintagel to sell exotic goods.

Tintagel must have had something worth buying.

-For the people who are coming up the Atlantic seaboard they would see Tintagel in the distance, that is the place that they are aiming for, that is their destination.

It's an important harbor that will give them the resources that they want.

-Whoever ruled Tintagel, had access to a rare commodity in high demand across Europe.

The secret to Tintagel's Dark Age wealth and power lies at the end of a quiet country track.

This is a vast tin mine -- just 15 miles away.

Exploited by the Romans, it was still in business at the beginning of the 20th century.

What looks like a natural gorge was once a massive mine -- 120 feet deep, 130 feet wide, and 900 feet long.

♪♪ Tintagel lies on the larger peninsula of Cornwall.

The rocks in this area are one of only three sources of tin in Western Europe.

The metal was one of the reasons the Romans came to Britain in the first place.

-Whoever's been mining that stuff for hundreds of years is going to get rich because the Mediterranean needs those resources.

They will come to you to get them.

-Tin, when mixed with copper, makes bronze -- vital metal for Roman weapons.

Even after the Romans left Britain, Europe continued to buy Cornish tin.

-Whoever controls Tintagel is at the head of a large financial empire.

We mustn't think of them as being on the margins of anything.

They are at the center of a very sort of dominant, successful political world.

-In dramatic contrast to the traditional view of the Dark Ages, trade in the west does not collapse after the Romans leave.

The connections to the continent remain, and they continue to influence every aspect of life.

Evidence for this influence is found on the very last day of the Tintagel dig.

Jacky Novakowski's team makes the most exciting discovery of all.

It's a stone, used to make a windowsill in Building 94.

And someone's been writing on it.

-There's at least three lines.

It's either an "A," with a hat on.

♪♪ -I think it's okay actually.

♪♪ I'll wrap it up first.

It's very heavy, yeah.

-The stone is transported to the labs at Fort Cumberland for closer study.

James Gossip gives Alice access to this rare find.

-So, this is it?

-This is it.

-It's really clear.

That's amazing.

-The letters were scratched with a sharp tool, roughly, as if for practice.

-It's not in its original position.

Probably only ever a trial piece anyway.

Just somebody practicing their inscription.

So presumably, once this was created as a trial piece it wasn't that important anymore and it was incorporated into this wall where we found it.

-It's one of only a handful of inscriptions from this period ever found.

The Dark Age etching gives precious insight into the lives of the people living at Tintagel.

First, there's a distinct flavor of Roman Latin.

-So, the top line is here, possibly "Tito," which could refer to Titus.

-So that's a Roman name.

-That's a Roman name, yep, popular in the Roman and post-Roman world.

Here we've got a word which could be "Viridius."

Another name, another Latin name.

Or "Viri duo."

-I think I can make out the letters here.

I mean that looks like "Fili."

-Yup.

That's right.

-But there's also local dialect.

-What does this say here?

-We think this is perhaps "Budic" -- B-U-D-I-C.

There's a word that's common in Welsh, Breton and Cornish contexts.

-Ah, so this, so this isn't Latin?

-That is not Latin, no.

That's Bretonic or... -Yeah.

-It's the Cornish word form basically.

-The people here seem to be fluent in more than just one language.

-And then a "T" here?

-Yeah.

Perhaps, um, T-U-D.

"Tud."

-A possible translation is... "From Titus, to Viridius, the son of Budic Tuda."

The text's layout and few legible words indicate the inscription was for a monument.

It was discarded at the time, but centuries later, it's exciting proof of a sophisticated culture.

-This is a lovely "A."

That's a really nice style.

-This is the style of lettering that they're using in manuscript at the time.

It might even have been designed to be a deliberate Biblical connotation.

-It takes time and skill to inscribe stone, and money to pay for it.

The writer was part of a complex and wealthy society that valued both faith and craftsmanship.

-And this coming out of the Dark Ages when we used to think people were living in hovels, scratching around, illiterate.

-Yeah.

But actually created by a literate Christian elite at Tintagel.

-I wonder who did it?

I want to know.

-Perhaps Titus.

-So we're seeing these sort of debased forms of Latin inscription surviving in Cornwall.

But it does tell us that what we've got there is a literate society.

They're not at the margins of anything.

-Civilization didn't collapse when the Romans left Britain.

Tintagel in the west stayed connected, thriving and interacting with Europe as it had probably done for centuries.

The archaeology has revealed so much about Tintagel in the Dark Ages.

The prominence and stature of the buildings being unearthed here, along with the high-value pottery indicating the apparent wealth of their residents, may help explain another mystery -- the connection to Geoffrey of Monmouth's King Arthur.

-The dig at Tintagel is showing us that this rocky promontory sticking out into the Atlantic was not only a trading hub, but also a remarkably high-status site.

So perhaps there was someone, someone powerful, who much later would inspire that myth of King Arthur.

-King Arthur was a construct, created from fragments of the written historical past.

But Geoffrey chose Tintagel for his birthplace because it really was a seat of power in the Dark Ages.

-And that in a way is what we're talking about when we're discussing Arthur.

He is the literary creation based on that kind of primary evidence.

Whether or not he was real I think is irrelevant.

It's the period itself that -- that is essential.

That's what draws archaeologists and historians to it.

It's so important for understanding what made Britain today.

-The biggest revolution in Dark Age archaeology has been this recognition that Britain is fully connected to the continent all the way through.

♪♪ -The maritime connections are absolutely crucial here.

Tintagel is connected down to France and Spain and up to Wales, Scotland and Ireland.

It's right at the center of this Atlantic trading network.

-But in the east of the country, the connections were to Northern Europe -- the Angles and Saxons, with their very different beliefs and culture.

♪♪ All the archaeological evidence points to two societies not facing each other across a battlefield, but living very different lives.

-It's an economic divide between two halves of Britain, two distinct trade outlooks.

It's not a picture of conflict.

-The two halves of Britain are looking in different directions, going outwards rather than clashing in the middle.

-I think if you look at the sea instead of the land, and the rivers instead of the land, I think you have a much better chance of understanding where people are coming from.

♪♪ -At Tintagel, the excavations are complete.

The new discoveries have revealed that rather than being filled with violent conflict and turmoil, the Dark Ages were a time of trade and continuity.

Somewhere between the archaeology, written history and myth, a new truth has emerged.

-There are elements in there that all feed into one another and all help -- help us to understand the past, and you've got to try and master all these things to really get a clear understanding of what's going on, especially something like the 5th or 6th century.

-But the myth of King Arthur endures.

♪♪ -It's a myth.

But it's such a wonderful myth.

-He's a literary invention -- a romantic hero who embodies the ideal of kingship, and not a real historical figure.

-It's still something that resonates today because we all sort of need an heroic character to defend what we think is right and good, and it's Arthur who sort of fills that void.

-Next time, in the long reign of the Egyptian pharaohs, there was one moment of true chaos.

-The fact that the pyramid was robbed means the government was losing control.

-Was the empire threatened by violence... -All the evidence points to the fact that these were soldiers.

-...or were they victims of something far bigger?

-If anything goes wrong with the Nile, then it would be famine and chaos.

-"Egypt's Darkest Hour," next time on "Secrets of the Dead."