Kingdom of Conquest Castles: Britain's Fortified History

Castles have been part of our landscape for a thousand years.

Arriving as a tool of Norman invasion,

they spread to the furthest corners of England.

Then in the 13th century Edward I, an English warrior king,

pitted the people of Britain against each other.

Edward would use castles to become an emperor in the Roman mould,

to seize the crowns of his rivals and recognise no superior.

Edward was playing a real game of thrones.

In Wales, he would build gigantic fortresses to subjugate the Welsh.

They would be colonial headquarters,

symbols of engineering genius and brutal military occupation.

But triumph in Wales would turn to failure in Scotland,

as a new champion emerged to turn castles against the English.

What followed was a struggle of epic sieges

and terrifying weapons, to determine the future of the kingdom.

It was an era of unparalleled aggression,

that saw castles reach the peak of their design.

And behind it all is the story of the greatest castle-building king

these islands have ever seen.

An intense conflict is under way.

Vast armies are on the march and thrones are at stake,

amidst some of the mightiest walled cities and castles ever seen.

But these castles aren't here in England.

These are the great Crusader fortresses of the Holy Land.

The armies are engaged across the Holy Land and right in the middle

of it all, taking it all in,

is the future king of England, Edward Plantagenet.

The House of Plantagenet had ruled England for more than a century.

A powerful royal family with lands across France.

The son of King Henry III, Prince Edward, was nicknamed Longshanks

for his intimidating height,

with a furious temper and ego to match.

The warrior prince had gone on crusade in 1271 and been inspired.

He returned with ambitions to expand his kingdom and his power.

For Edward, castles were the key to fulfilling the destiny

he had in mind.

Castles would be his Camelots, the HQ of brand Plantagenet.

Not only a tool for conquering the countries around him,

but for permanently colonising them

and reshaping their way of life as he saw fit.

The fate of Wales and Scotland would turn on the building

and besieging of castles.

In 1272, on his way home from the Crusades,

the prince learned that his father had died

and that he was now Edward I, King of England.

He'd soon embark on his first colonial project...

Wales.

The borderland with England was known as the Marches,

a dangerous frontier controlled by the violent Marcher Lords,

who worked on behalf of the English Crown.

North Wales had its own independent nobles

and there was constant friction.

This is White Castle, in the heart of the Marches in Monmouthshire.

In the 1250s, it became one of the young Prince Edward's

very first castles.

In the 1260s, the situation in the Welsh Marches had reached

boiling point. One northern Welsh ruler, Llywelyn ap Gruffydd,

had expanded his power here, in a way that panicked not only

the Marcher Lords, but the English monarchy itself, and

it became a major thorn in Edward's side.

Llywelyn was an independent ruler from the House of Gwynedd,

whose lands centred around North Wales.

He adopted the title Prince of Wales, as overlord of the Welsh.

His territory grew throughout the 1250s and into the '60s.

You can see the effects of this growing standoff

in White Castle itself.

This entire castle was once rendered in white, hence the name,

and although that is quite a significant statement

this place has no airs or graces.

It's an entirely military set-up with no creature comforts.

It's a powerful reminder of just how tense things had become here.

The rise of Llywelyn had not gone unnoticed, and in the 1260s

Edward gave this place a massive makeover.

Edward used the very latest ideas in castle design

to strengthen the defences.

Round towers were added along the castle walls.

They're four storeys high and pierced only with arrow slits.

Round towers were more difficult to undermine than

the square towers, because the corners of square towers were

their weakest point.

In fact, if you look all around the curtain walls here,

you won't find a corner anywhere.

It was also more difficult to rest a siege ladder against a round tower.

Fighting from siege ladders was difficult enough, but it was almost

impossible if you were trying to keep your balance as well.

The new arrow slits were an unusual design that allowed bowmen

to track their target horizontally along the steep moat.

It was uncompromising stuff,

a response in stone to Llywelyn's growing power.

The independent Welsh rulers of Gwynedd had castles

and ambitions of their own.

In Llywelyn's hinterland territory stood Dolbadarn Castle,

one of his most prized strongholds.

The mountains of Snowdonia themselves were said to be

like a castle for the Welsh kings, and Dolbadarn guards a key pass.

In fact, the mountains formed part of the castle itself.

You can see how these outer walls are built up of un-mortared slate

mined from the surrounding area.

The Welsh didn't just build castles to keep outsiders out,

but to control their families as well.

Under the Welsh system, inherited lands were divided up

between sons rather than going to a sole heir.

This meant men like Llywelyn needed secure prisons

for scheming brothers or cousins.

He imprisoned his own brother Owain

in this tower for 22 years, earning him the scorn of a Welsh poet,

who questioned whether he'd got his priorities right.

"There is a hero in a tower in long captivity

"A brave, kingly, sovereign hawk

"A hero whose loss I feel from among the living

"A hero who would not allow England to burn HIS border."

Llywelyn had risen to the top at the cost of his own brothers,

but his grip on power was fragile.

For a while, Llywelyn was secure in his achievements.

By 1267, he ruled around 75% of the Welsh population.

But this was a man under pressure.

That same year he signed the treaty of Montgomery,

which, for the first time, formally acknowledged his title

as the Prince of Wales, but which also committed him to paying

vast sums of money to the English Crown.

It was a determined attempt to stay independent of England.

But then Llywelyn made a catastrophic mistake -

insulting Edward I.

He refused to acknowledge Edward as his King five times in a row

and the feud exploded into open combat.

King Edward fielded the largest army

since 1066 against this Prince of Wales.

Not for nothing is he known as Llywelyn the Last.

By the time the hard-fought wars had ended, Llywelyn

and his brother Dafydd were both dead, and the timbers of Dolbadarn

were carried off by Edward to build a castle of his own.

The House of Gwynedd was finished.

Edward took direct control of Wales and developed a strategy

to subdue the Welsh permanently.

The King built castles that would change

the very shape of their country.

These would be the mightiest fortresses Europe had ever seen

and were the tools with which Edward would not only conquer Wales,

but colonise it.

Wales was ruthlessly oppressed.

Edward I constructed a series of castles,

described as an iron ring around the north of the country.

There were 17 in total,

with enormous new fortresses at Conway, Harlech and Beaumaris.

They were later described by one Welshman as magnificent badges

of our subjection.

To supervise the vast construction process,

Edward summoned a Master Mason from Savoy, called James of St George.

He'd worked on a number of major castles in Europe.

He was part engineer and part project manager

and the man who made Edward's castle building obsession a reality.

The most spectacular of his creations was built

here at Caernarfon.

If you look at Dolbadarn and look at Caernarfon,

what strikes you is the huge size of Caernarfon,

the shear wealth that went into it.

A modest ruler in Gwynedd couldn't even dream of building

something on that scale, but Edward I could.

King Edward had Caernarfon designed for military domination,

but he took advantage of history to give it cultural firepower as well.

Edward knew that to gain traction in Wales and to make his rule last,

he not only needed enormous military bastions,

but to make it seem as though his reign was inevitable.

Like a fulfilled prophecy, as though ruling Wales was somehow fate.

As James of Saint George was constructing Caernarfon,

workers discovered a body.

It was claimed to be none other than Roman Emperor Magnus Maximus,

then thought to be the father of Constantine the Great.

Edward ordered the body to be reburied in a local church.

A cynic might say this was all suspiciously convenient.

What better sign could there be of Edward's greatness

than following in the imperial Roman footsteps?

But there's even more to it than that.

Co-opting Roman power and prestige was good,

but that Maximus was also linked to a Welsh legend was just perfect.

And that legend was the Dream of Macsen Wledig,

the Welsh name for Maximus.

In this tale, Macsen dreamed of travelling from Rome to a land

of high mountains and arriving at a river flowing into the sea.

There was a great fortified city with towers of many colours

and a great fort, the fairest man ever saw,

with the image of eagles in gold sat by an ivory throne.

At Caernarfon, Edward took this imagery of the past

and built it into his castle.

And here on top of the Eagle Tower,

you can see how those symbols of legend were made real.

Three stone eagles like this one were set atop the Eagle Tower,

possibly gilded for all the world to see.

It was particularly clever because the eagle is a symbol

both of the Roman Empire and from centuries-old Welsh folk stories.

The architecture cemented an imperial connection.

Bands of coloured masonry and polygonal towers were

inspired by Roman designs like these in Constantinople,

known today as Istanbul.

The incorporation of more elaborate practices,

for example Krak des Chevaliers, which is now in Syria,

which was built by the Crusaders.

You can see elements of those castles in Caernarfon.

You can even see elements, some people claim, of Istanbul,

because the towers on the corners have got bands of different stone.

Edward the Crusader knew well the value of sturdy walls

and international symbolism.

The lords who once united the Welsh were dead

and the King wanted Welsh unity to stay dead with them.

But Edward could use their legacy for his own ends.

In 1284, his wife Eleanor gave birth to a son within these walls

and presented the King with a chance to bind Wales to the English Crown.

For years tradition maintained that the young prince was born here

in this room in Eagle Tower, but we now know that the castle

was then a building site and that this floor had yet to be finished.

The prince was born in Caernarfon Castle and Edward

deliberately chose it as the location for the birth.

According to legend, he had a very good reason to do so.

The story goes that his new Welsh subjects implored

the King only to anoint a new Prince of Wales

who was born in Wales and who spoke no word of English.

The crafty Edward realised that his newborn son,

who couldn't speak at all, fitted the bill perfectly

and he handed his son the title.

From now on, the title of Prince of Wales went to the first-born son

of every English monarch.

What had been the proud boast of Llywelyn's ancestors

was claimed for England along with all of their lands.

Surrounded by a resentful population,

Caernarfon was designed with a myriad of defences.

And, like all of James of St George's castles, it was supplied

by the sea, making it that much harder to cut off during a siege.

Soon enough, Caernarfon faced its first proper test

and it failed spectacularly.

In doing so, it highlighted a real problem for castle builders.

Castles were mighty strongholds when the walls were up,

but what happened when they were being built?

In 1292, work had been halted.

The walls of the town were largely complete

and the southern side of the castle was built high.

But the north was a different matter,

and, in 1294, there was an uprising.

At the time of the rebellion, none of this was here.

The entire north face of the castle was unfinished.

It was only protected by the town walls and by a timber palisade.

So, rather un-sportingly, the rebels just hopped over the barriers,

took control of the castle and burned everything in sight.

The castle was retaken six months later.

The results of this incident are visible

in the fabric of the castle itself.

The south facade has a stylish and elegant construction.

But here on the north the stonework is a bit rougher,

completed in a bit of a hurry.

Gone is the eye for detail and the multicoloured layers of stone.

They just wanted it fortified and sharpish.

At Caernarfon, James of St George led an international

building project, with a small army drafted in to work on it.

He had assistants with ideas and expertise from across

the continent, but the bulk of his workforce were a different story.

Although Caernarfon's about as far as you can get from England,

all of the labourers and workmen who built this place were English.

Edward had them shipped in from as far afield as Kent

and Cumbria in their thousands.

The Welsh simply weren't trusted to work on his pet castle.

Castles were, of course, entirely handmade

and the skills required to make them were highly prized.

Andy Oldfield is a modern-day master mason.

Andy, what was the place of the mason in the medieval world?

It was one of privilege. The actual mason,

they were one of the few people that could actually travel.

They would actually, not just travel to the next town,

but travel to the other side of the country, travel to the other side of

the continent if they were in demand, hence why we get the term, Freemason.

They were allowed to freely travel.

The key building block was the ashlar,

the tough and squared-off facing stone on the front of the walls.

We're going to make one the old way.

We're going to split this stone the old-fashioned way

using plug and feathers.

Plug and feathers is just a series of metal wedges, really.

These are classed as the feathers and this is a plug.

We're going to insert them into the hole

and put the wedge down between them.

We'll put them in to push the stone apart.

It doesn't take a lot of strength.

What it does take... is a bit of gentle tapping.

As we start to hit it with a hammer, they start to talk to you.

They sing to you. The noise they make tells you how far the stone

is through before it breaks.

-Keep going until the feathers talk to me?

-They do indeed.

Gentle taps, because you're not trying to smash your way through.

-Is that all right?

-That's fine.

-That one is singing a bit.

-There we go.

Talking feathers.

There we go, it's getting close. And there we go.

That's it, as simple as that. You can give it another tap if you wish.

There we go, it's done. Hooray!

What we have there, if we just pull it apart,

is two stones ready for the next stage of carving.

It's amazing how effective these tiny things are.

This is a piece of stone I could never pick up

but I've managed to break it in half with just a few taps,

playing the stone xylophone with these feathers and it cracked.

It's amazing.

Were there different skill levels of mason?

There were, in fact there were about seven levels,

from the rough hewers down in the quarry, right up to the master mason

who was the architect who put together the designs, made sure

everything worked together and it all stayed up and didn't fall down.

-Was it a really treasured skill?

-It was a protected skill.

It was highly protected.

The more knowledge you had, the greater you could earn,

-the more power you wielded.

-How was that knowledge passed down?

Through a very strict and very close guarded secret to training.

They would set up a lodge,

which is where a lot of the carving work went on.

They also...they didn't necessarily sleep in the lodges,

but they took their meals in there and that's where

a lot of the training went on for the apprentices and where

they were assessed to whether or not they could make it to be a mason.

-What's next, Andy?

-This is the next process. It's called boning in.

Basically involved cutting four small areas, it didn't have to

be in corners, it could be anywhere using a mallet and chisel.

What we do is we gently create a flat surface.

-They had to be flat enough to put one of our boning blocks on.

-I see.

This is where it really becomes part of a skilled trade

and deep dark secrets of the masons.

Then we're going to take our flat surface, a straight edge,

and this was the mason's Bible.

We've got to create a flat surface out of this moonscape of a rock.

A mason would look between the two levels,

top of the levels of stone and to see if they lined up.

-If they didn't line up...

-Between this one and this one?

-Yes.

You'd sight your way through and if they didn't line up,

you'd know one of those corners was a bit higher, a bit lower.

You'd trim a little bit more out

until both of those straight edges were in line.

-Right, there we go.

-I think that is pretty good.

I think we're about there at that.

If we put these blocks on, because we always have to check.

It's about checking your work all the time.

Using our straight edge again and one of our chisels.

We look down again and check again. You check from your side.

-That looks pretty good to me.

-I think we're bob on at that.

That's pretty good.

After chipping away the waste from the middle,

the surface is smoothed off.

You're virtually there at that. Then the final process.

With any ashlar, you've got to make it square,

so it fits in, and build a building block.

It was the mason's square which enables them to do this.

By etching a straight line with the set square,

a tool called a pitcher, can be used to create the flat edge.

Be gentle, now. Excellent.

When I think about medieval buildings,

it's so easy to compare castles with cathedrals, which seem

so much more complex in their construction.

Is that a fair way of thinking about it?

A castle was designed for one thing only

and that was to withstand being stormed and broken into.

It was quite a complex sort of design to take a lot of abuse.

Now we've got our mason's mark. You've got to sign it.

Be proud of my stone.

The masons at Caernarfon were working on something that

hadn't been seen on these shores before.

Edward I's new fortresses had a colonial town built into them.

These were known as bastides, an idea taken from Gascony.

For Wales, he built the most heavily fortified version possible.

Bastides were a truly colonial idea.

They were surrounded by higher walls and laid out

on a military-style grid system.

They were designed to provide both goods and taxes

and were even subject to their own colonial laws.

Bastides were a way of generating income for the project.

But in Wales, the King's new bastide towns had a far more sinister side.

The Welsh were cut out and the English filled the townships.

It was clear that the building of these new towns represents

a process of deliberate Anglicisation of North Wales,

by bringing in new towns which the Welsh were totally unaccustomed to

and bringing in new settlers from England.

These civilian settlements formed part of a classic frontier-land.

Hostile territory peopled by a defeated enemy.

The last castle Edward built in Wales would be Beaumaris,

meaning beautiful marsh.

Standing on the island of Anglesey,

it was intended to be the crowning glory of the iron ring

and the finest work of his master mason, James of St George.

Beaumaris was a military masterpiece,

planned with an almost impenetrable series of defences.

It was based around the idea of concentric walls,

essentially, building a castle within a castle.

Like so much else, it was a lesson learnt from the great

fortresses of the Holy Land.

If you were an attacker and you managed to make it through or

over this wall, you'd then be trapped here in a killing zone.

You'd face a constant barrage of missiles and

you still had to make it past this even bigger wall.

If you were a defender, you could mount a solid defence

of the outer walls, firing over the moat

while constantly being protected by covering fire from your

comrades here up on the inner wall.

If that outer wall was then breached, you could retreat here.

Every time the attackers were slowed down by a new line of defences,

whether it was the moat, the outer wall, or the inner wall,

they were exposed.

James of St George was now known

as the Master of the King's Works in Wales

and Beaumaris offered him something unique.

Unlike all the other castles in the ring of iron,

Beaumaris was built on an entirely new site.

It was a blank canvas,

and it allowed Master James to build exactly the castle that he wanted.

The flat marshland terrain allowed him to build an almost

perfectly symmetrical fortress, with no compromises in form.

More than 2,500 people were brought in to work on this project

in the first year alone,

and the castle bears scars of that construction process.

These holes are for scaffolding poles

and they arch their way around the tower

and they were used to support a distinctively spiral

type of scaffolding technique that was imported from

Master James' homeland of Savoy.

But there was a problem. Castles were enormously expensive

and Edward's brutal wars had almost bankrupted the kingdom.

For all its design genius, Beaumaris was never actually finished.

In 1296, James of St George wrote a letter complaining of tightly

squeezed budgets in a way some of us might still recognise today.

"We write to inform you that the work we're doing is very costly

"and we need a great deal of money.

"In case you should wonder where so much money could go in a week,

"we would have you know we have needed and shall continue to need

"400 masons, both cutters and layers,

"together with 2,000 minor workmen, 100 carts, 60 wagons

"and 30 boats bringing stone and sea coal, 200 quarrymen,

"30 smiths and carpenters. PS, and Sirs, for God's sake,

"be quick with the money for the works, otherwise everything

"done up till now will have been of no avail."

At the national archives, there's a document that takes us

behind the scenes of the building of Beaumaris.

This manuscript is known as a pipe roll.

It's 700 years old and it's a financial record written on vellum

and sent to the Treasury.

It records all sorts of details relating to royal expenditure

and debts owed to the Crown.

For storage, it was rolled up tightly,

which is why it's known as a pipe role.

This one details the royal accounts for the construction

of Beaumaris between 1295 and 1298,

from a clerk called Walter of Winchester.

It may be the musings of a medieval accountant,

but there's so much detail here, you get a real glimpse into the past.

The roll gives you a sense of the sheer scale of the work being

carried out, because it records the volumes of material

needed by the builders.

In the first year alone, it talks of 220,000 nails

and 48,000 tonnes of stone.

Building a castle was a labour-intensive process

and the site would have been swarming with people

and, rather wonderfully, we can work out from the pipe roll

what these people were paid.

Here, it says "forsata et motam", referring to the labourers

building the ditches and the moat

and also to the stipend cementariorum,

which is talking about the wages of the masons.

We know that labourers might have been paid as much as eight pence

per week but that a skilled mason would earn three times as much,

a more reasonable-sounding 22 pence per week.

The period covered by these accounts was the last time any serious cash

was available for his castles.

By 1298, construction at Beaumaris had effectively halted.

James of St George's masterwork would remain unfinished.

Edward had run out of money but he'd always had

an eye for an opportunity.

As King, he didn't actually own all the land in his kingdom,

so one of the quickest ways of raising cash was to expand

his royal property portfolio by whatever means necessary.

Among the property in his sights was that owned by one

Isabella de Fortibus, the richest lady in England

and a woman sometimes described as the Queen of the Isle of Wight.

Isabella had become a widow at the age of just 23.

She inherited her husband's land and title

along with some of her late brother's estate.

It gave her much of the Isle of Wight, as well as extensive

lands on the mainland.

Isabella was not just wealthy, she was also determined.

She's a character who demonstrates

the often overlooked power of women at this time.

Isabella made her home here at Carisbrooke Castle.

She transformed the fortress into something befitting her wealth

and status.

Throughout her life, she continually sought out new additions.

Her greatest innovation happened here.

We know that Isabella was one of the first people to use glass

in castle windows and this is a particularly beautiful one,

complete with window seat.

It was some of the very first glass used in a secular building

and eye-wateringly expensive.

But for Edward a rich widow was a tempting target.

As a widow she had a degree of legal authority and security,

but it also made her an attractive target for greedy suitors.

We know she evaded at least two nobles whom the King had said

could marry her.

Edward made repeated attempts to buy control of Isabella's land.

He went so far as to challenge her in court,

and, in a mark of her strength, she took him on and defeated him.

It should come as no surprise

that among the items listed in her household

was a full set of the code of laws.

Eventually, however,

even a lady as strong as Isabella could not resist for ever.

Her husband and brother had died when she was still young

and she outlived her children.

As she lay dying,

the King's counsellors made her sign away her lands to Edward.

Or so it's been claimed.

For years Isabella had resisted Edward's attempts to gain her lands.

Finally, it's only on her deathbed that agreement is reached

and one wonders, this poor old woman, lying ill and sick,

could she really have agreed to a sale

that she'd resisted for so long?

It seems very, very questionable.

Edward's ego was still not satisfied.

He would seek out new lands, new power and new money

by conquest.

This time, turning north for Scotland.

In 1296 Edward invaded,

determined to take the Scottish throne for himself.

But even this mighty king's plans were limited by his finances.

It had proved difficult enough for King Edward to raise

enough cash for an army.

There was simply not enough money left in the coffers

to start building huge castles like he had in Wales.

The war in Scotland, it was hoped,

would capture a new source of income.

That he would have access to the revenues of the Scottish Crown

and that those would be used as a way of effectively making

the English occupation of Scotland pay for itself.

It didn't happen.

When it came to Scotland, Edward's wars would be fought

with the existing castles and the outcome would be very different.

Edward's Scotland campaign tore through the country

but, no matter how hard he clamped down,

defiant pockets of resistance kept springing up.

July 1300.

The English King marched north from Carlisle

to the border castle of Caerlaverock.

With the army were huge wooden weapons,

catapults known as trebuchets and other siege engines,

all designed to overwhelm the castle.

Caerlaverock's Scottish defenders were about to feel the full wrath

of Edward Longshanks.

Edward and his army arrived exactly here, looked out across the moat

towards those curtain walls and that massive gatehouse.

3,000 soldiers and 87 knights, all armed to the teeth

and equipped with the very latest engines of war, prepared to attack.

Manning the triangular-shaped battlements was the garrison

of Scottish troops, poised to do everything they could to stop them.

This castle would be no pushover.

A herald accompanying Edward's army described the events of that day

in a poem called The Roll Of Caerlaverock.

It's one of the most detailed accounts of a medieval siege

to have survived the centuries.

"Caerlaverock was a castle so strong

"That it did not fear siege before the king came there

"For it became it not to surrender."

But Edward was no ordinary monarch.

Longshanks was a master of castle warfare, and the brave defenders

of Caerlaverock stood in the way of his imperial ambition.

The foot soldiers went in first

and attacked the gatehouse with everything that they had.

The garrison responded with a hail of arrows,

stones and crossbow bolts.

What happened next was described in stark terms in the poem.

"The footmen began to march against the castle

"And it might be seen fly among them stones, arrows and quarrels

"But so effectually exchanged those within with those without

"That in a short time many bodies there were wounded and maimed

"And I know not how many killed."

From inside the gatehouse, the defenders would have seen

the landscape literally heaving with soldiers,

all hellbent in getting through or over these walls.

It would have been a terrifying ordeal.

The purpose of a castle like Caerlaverock

was to avoid open battle.

If the walls were breached, the garrison would have

to defend themselves in armoured hand-to-hand combat.

Andy Deane is an expert in medieval martial arts at the Royal Armouries.

-Sword?

-I have my sword.

And you'll need a buckler. OK.

One of the many weapons that are shown on medieval manuscripts...

I like a shield I can hide behind. What is this?

This is the most magnificent weapon because it's not for hiding.

-It's like a saucer.

-It is brilliant.

It's your own Jedi force field, that buckler.

It is, because as people come swinging down... Let me show you.

Stand by for some swashbuckling!

Now, you always want to try

and keep the buckler out in front of you and/or covering your hand.

This is the sort of position, it can either come over the top

or it can come back this way there.

But you want the pointy bit threatening the bad man,

that would be me. OK.

So from here, now you've got the pointy bit in front of you,

I've got to either come round it, over it, under it somehow, yeah?

-Yeah.

-So the most important thing...

One of the things they talk about in the manuscript

is engaging your opponent's sword.

If you can engage your opponent's sword, you know where it is,

so maybe you can just simply come under and then straight up.

Or if you were engaging from the sword,

have both of them out in front of you, maybe you just slide through,

take both weapons and pull yourself through and down.

The lowest men on this ladder of seniority,

what sort of weapons were they using?

Well, I suppose the things from the farm

that were laying about are easily manipulated into deadly weapons.

You can have a bastardised farming utensil - sharpen it up,

shove it on a long stick and away you go.

So we're starting right at the bottom, the very agricultural...

-You've got the English billhook.

-Wow, look at that.

Now if you imagine just this bit here and the small handle,

that's where you're laying your hedges. You've got this curve here...

-Like a scythe.

-Yeah, exactly.

And now, sharpen it up,

send it down to the old smithy, stick a couple of extra spikes on it

and now you've got a weapon that is sublime

at taking out other infantrymen.

Back of tendons, neck areas...

It's all there for them with a very basic weapon.

So for a farmer, laying a hedge is the same

as cutting someone's Achilles tendon?

Well...or the backs of the knees, yeah. Exactly.

Lots of skeletons that have been found on various battlefields

from the Middle Ages...

So many of the wounds are on the shoulder,

neck area or the backs of the legs, so they've obviously been

brought down and then a slightly longer weapon is easier to do

than a sword. As long as he's not a threat any more, you've done your job

and, as you're working in a tight press, the next person

or the young lad just comes behind, does that job and you move on.

Next person, next person.

At the siege of Caerlaverock, it wasn't just enemy soldiers

but technology that the defenders were fighting.

They also faced catapult-like giant trebuchets.

Siege engines continually hurled rocks

that shattered into sharp and deadly fragments against the stonework.

Archaeologists have found stone trebuchet balls littered

all around the grounds of Caerlaverock Castle.

With a certain black humour, some of the machines

were even given nicknames, like Brother Robert,

after the priest that operated one of them.

The garrison's morale began to sink as the situation became hopeless.

One of them was killed by a flying boulder,

the walls and roofs began to crumble around them

and the Scottish troops had no choice but to surrender.

When the gates finally opened, only 60 men emerged from the rubble.

The poem says that Edward's army marvelled at how so few men

had given such fierce resistance.

Caerlaverock showed just how effective castles were

as force multipliers,

increasing the effectiveness of each soldier exponentially.

Just a small number of soldiers could slow down and even stop

a much larger force, and when you're moving through enemy territory,

every extra day taken was another day that you had to feed, maintain

and, most damagingly for Edward, pay your troops.

The Scottish were not going to give up easily.

Caerlaverock was a modest-sized castle...

..but Edward I would soon face a stronghold

on an altogether different scale -

Stirling Castle.

By 1304, Stirling was the last major castle in his opponents' hands

and it appeared to be the key to the whole kingdom.

It was the most strategically important castle in Scotland,

the natural gateway between the Highlands and the Lowlands.

Stirling is very much like something

that Edward himself would have built.

The castle on the rock today was built centuries later

than the original Scottish fortress,

but you can still see how ideal the site was - perfect to defend,

radiating authority from a commanding position,

visible for miles around.

Edward must have hated it.

Castle warfare had become like chess.

If you controlled Stirling, then you controlled all of Scotland,

but if it lay in the hands of your enemy, even if you controlled

all the castles around it, they could still hold you to a stalemate.

The royal army gathered artillery from all over Scotland.

The lead was stripped from church roofs to make weights

and missiles for trebuchets to fire an "unbearable rain of metal".

They fired huge rocks

and a type of incendiary known as Greek fire at the castle.

Edward even had a window installed in the Queen's lodgings

so she could marvel at his kingly prowess.

Edward threw everything he had at it,

but Stirling was nigh-on impregnable.

He had 17 siege engines, teams of miners, thousands of soldiers,

but he was held off by a garrison of just 30 men,

many of them hidden in caves and tunnels deep under the castle.

After four months of bombardment, the castle still hadn't

been captured and Edward was getting impatient.

Time was money and there was already pressure on the royal purse.

So Edward brought in his greatest weapon yet -

an enormous siege engine he'd had specially made.

He called it the loup de guerre, or the Warwolf.

This new weapon to terrorise the enemy was a type of trebuchet,

the heavy artillery of its day.

It may have been the largest ever built

and took five master carpenters and 50 men months to construct.

To see one of these fearsome weapons in action,

I've headed south to Warwick Castle.

This is the Ursa, or She-Bear.

It's a replica of a 13th century trebuchet and it gives you

a fascinating insight into how these terrifying weapons actually worked.

It's 18 metres tall, it weighs 22 tonnes,

but Edward's Warwolf may well have been bigger.

It's quite a piece of engineering.

Siege engines like this could devastate castle walls.

-Hi, Charlotte.

-Hello there.

-How are you doing?

-I'm all right, thank you.

How does this wonderful thing work?

OK, basically, two people in each of the wheels here.

As you walk in the wheels, it pulls on the big rope here

that's attached to the top of the arm

and, as the arm is pulled down, the box goes up.

-And then you let fly?

-Yes, and then we let fly.

The counterweight is around five tonnes

and is winched to the top as we turn the wheels.

A projectile is hooked on and when the weight drops to earth,

sending the arm up, it's hurled like a bowler's action in cricket.

-Hello.

-Hello.

-Thank you. Safety hat.

-Right.

-Winders, are you ready?

-Ball ready!

-Walk on!

-Whoa...

-You all right?

-Yeah.

Bring yourself forward and straighten your back.

Look out to the side so that you're not...

Winders, slow and halt.

SAM LAUGHS

I'm hilariously out of breath.

I feel sick, my calves hurt, my legs...everything hurts.

It feels so dangerous.

There must have been some terrible trebuchet accidents

in the 13th century.

Right, Charlotte, I'm out of breath.

I'm not sure anyone else was doing any work, I think it was all me.

So it's primed, it's good to go. How big are the balls?

These are the balls here. So this is one of our fireballs.

-It's about 18kg, so about 2st.

-Quite heavy, yeah.

It's about the smallest thing we can shoot,

so the largest thing we can shoot is about 150kg.

-Sorry, how big did you say this was?

-This is 18kg.

18, and you can throw something that's 150?

-Yes, so we can throw something a lot larger.

-That's a heavy bit of kit.

Trebuchets were also used to hurl everything from prisoners of war

to beehives to try and demoralise the enemy.

Clear the machine!

We're shooting the projectile they called Greek Fire.

Have a care!

That was amazing.

The noise was so sinister of that fireball

going through the air, it kind of roared.

And it stayed up in the air for so long in a huge, high trajectory.

This thing is still creaking and groaning like it's exhausted.

Even after all this time, it's an amazing piece of engineering.

And it can achieve the most extraordinary things.

That ball's gone miles down there, it still on fire.

It's a fearsome weapon.

At the siege of Stirling, the sight of Edward's giant Warwolf

must have been the last straw for the defenders.

Annoyingly for Edward, the garrison tried to surrender

before he could try out his new toy.

As they came out barefoot with ashes on their heads

as a token of surrender, he ordered them back inside,

saying, "You don't deserve my grace, but must surrender to my will."

Edward wanted to see his weapon in action.

He ordered, "The king wills it that none of his people enter

"the castle till it is struck with his Warwolf and that those within

"the castle defend themselves from the said Warwolf as best they can."

A few shots from Warwolf devastated the gatehouse

and, finally satisfied, Edward allowed the garrison

to throw in the towel.

The siege had dragged on and it had been an expensive business

and had cost him nearly £9,000.

In taking Stirling, Edward could've been forgiven for thinking

that he'd finally crushed resistance to his rule.

But he'd not banked on what would happen next.

The ageing Edward was about to face a new adversary

and rival for the Scottish throne,

Robert the Bruce.

Scotland had turned out to be much more difficult to subdue than Wales

and in 1306 Robert the Bruce had crowned himself as King.

As conflict with England escalated,

Bruce ordered his family to the safety of Highland castle Kildrummy.

Edward ordered his son,

the now-grown-up Prince of Wales, to besiege it.

He didn't have to attack for long.

Full-on direct assaults on castles were actually very rare

because there was usually a simpler way that a castle could be captured.

It was a matter of finding the castle's weak point -

it could be the gatehouse, it could be the source of supplies...

or it could be someone inside.

To hold out for as long as possible,

the defenders had filled the hall with grain.

At first, the prince's forces couldn't make any impression

on the walls or the garrison.

Then they found a way in.

Osbourne, the castle's blacksmith, was promised

"as much gold as he could carry" to betray them.

He set fire to the grain stores and the castle was done for.

Legend has it that the English paid him his gold

but, when the castle was later retaken by the Scots,

they melted it and poured it down his throat

as punishment for his betrayal.

Most of Robert the Bruce's family had made a lucky escape

before the fighting started

but not so the castle's commander, his brother, Neil Bruce.

He was taken to Berwick and hung, drawn and quartered.

King Robert lost many of his family and best men in castles.

Kildrummy was a painful personal and military lesson,

and one that he wouldn't forget.

A year after Kildrummy, Edward died

and his dream of an English monarch

sitting on the throne of all three kingdoms died with him,

as did his concept of castle warfare.

Edward had failed to conquer Scotland and the next generation

of Scottish rulers learned from what had happened.

The Bruce in particular recognised that taking on the English

at their own game simply wouldn't work.

He needed to develop a new strategy.

Castles were one of his biggest problems,

but the Bruce had a solution.

The first couple of years, he still tries to do the same thing -

capture a castle, garrison that for himself and hold it out.

He realises that cannot work and so when he captures the castles,

he destroys them.

And what he's fighting is a new style of guerrilla warfare

where fixed military installations like castles

no longer have a purpose.

And rather than match the English castle-for-castle,

he did the opposite.

He simply pulled down as many of them as he could,

rendering them useless to everyone, in his words, "Lest the English

"ever afterwards might lord it over the land by holding castles".

Stirling, the castle that Edward had invested so much time

and money in capturing, eventually drew the English to defeat

at the Battle of Bannockburn as they raced to relieve its garrison.

After the battle, Robert the Bruce, taking no chances,

demolished the castle, tearing it to the ground.

Under Edward, castles had become awesome in scale and military clout.

His successors would never again attempt to build anything

like the iron ring or use castles as an instrument of colonialism.

Times were changing.

Castles permanently stamped Edward's mark on Britain.

They represented his utter ruthlessness and his naked ambition,

but in the end their sheer expense contributed

to his failure to become King of all Britons.

According to legend, Edward decreed that he wasn't to be buried properly

until Scotland had been conquered,

and he was buried in a plain stone tomb.

So what would the future of castles be?

In the century that followed, they began to occupy a new place

in English life as icons of nostalgia for the nobility.

Writers of courtly literature fantasised about ideals of chivalry

that had never really existed, set amongst the great fortresses of old.

Castles became more about romance than war.

Take Bodiam.

In every sense it's the textbook image of a medieval castle.

It's imposing, it's grand and it really looks the part.

But if you look a little closer,

there's something really interesting going on.

Bodiam has been designed to make you think that it's mighty,

and along with it the owner who had it built.

The moat is not for protection,

it's there to enhance the appearance of the castle.

On a still day like this, the reflection's not only beautiful,

but it makes everything look twice as big.

The approach to this castle was brilliantly over the top.

Pass over this, which is a drawbridge,

past here, a portcullis,

through the barbican,

and then you were faced with another drawbridge

before you got to the gate,

there was a portcullis, and then once through that gate

there were two more portcullises.

It's so elaborate, it can only have been for show.

A nice bit of bling in rural Sussex.

Bodiam shows us that military architecture could be about style

or fashion as much as it could be about function.

An important part of that style was nostalgia

for the good old days of chivalry and perfect knights.

They were less and less important in war

and increasingly becoming symbols of a mythical past,

as much about the trappings of wealth and comfort

as martial strength.

Edward I would've found it hard to believe

but the days of castles seemed numbered.

Next time, how castles faced a new threat...

Firing the cannon!

..the arrival of the cannon. And it was not all military shock,

but artistic awe, as castles now colonised the imagination.