first and last line of defense . What secrets of the
ancient engineers lie hidden in colossal
walls behind massive gates, and deep within
macabre dungeons? The 26 mile round ring of
power built in just six weeks, a castle that created
Great Britain, the world's first invisible fortress,
the cannon that destroyed the longest lasting
fortifications in history and changed the
world we live in. Brand new research that is
pushing our experts further than they've ever been. The battle for the mega-fort
is our ancient discovery. [boom] [music playing] The colossal walls of
history's mega-forts still stand, thousands of
years after they were built. Billions of tons of stone and
earthworks all over the planet are proud reminders of a
mysterious past, a past full of surprises. The stories of the men who built
them, and tried to bring them down, created nations
and the world we live in. To discover these stories, we
must journey back to a time when men fought and built
to dominate an entire world. In 55 BC, Rome's most famous
emperor, Julius Caesar, led an invasion force of
80,000 highly trained soldiers deep into hostile territory. HARRY SIDEBOTTOM:
He wants glory. Glory is the great
vote winner in Rome. And he also wants money. He wants the loot. NARRATOR: He commanded
one of the best armies ever to take the
field of battle. It is the classic
army of all time. NARRATOR: But Roman
military might was to face one of its
greatest enemies, the Gauls. MIKE LOADES: This was
a formidable enemy. I mean, the Gauls were
a sophisticated foe on the battlefield. They were a match
for the Roman army. NARRATOR: Six years
of bloody battle had not produced a conclusive
victory for either side. JOHN NAYLOR: Caesar's troops,
worn down, ground down, was still prepared to take
the fight to the enemy. They were prepared to go
through hell for Caesar. NARRATOR: The Gauls also
had a charismatic leader, Vercingetorix. He was fighting, not for slaves
or loot, but for his homeland. In 52 BC, the
Gauls finally managed to come together under
their leader, Vercingetorix. NARRATOR: They rallied at
the hilltop fort of Alesia. Caesar's army
surrounded the town. The future of Europe
hung by a thread. They'd run the fox,
Vercingetorix, to ground. NARRATOR: Both armies
readied themselves for the final showdown. Caesar has to take
Alesia, or everything he's achieved in the previous
six years will probably crumble NARRATOR: Then Caesar
made a decision that is unique in military history. He ordered his men to
lay down their arms. JOHN NAYLOR: This
wasn't a battle that was going to be decided
with the sword and the javelin. This was a battle, and
indeed, a war and the country that was going to be
won with the spade. NARRATOR: To trap the Gauls in
Alesia, and starve them out, Caesar ordered the construction
of a fully fortified stockade, completely surrounding the town. 13 miles of defenses
built in just three weeks. How was this extraordinary
feat possible? The Roman army was an
incredibly sophisticated, trained, and drilled machine. NARRATOR: A legion of 80 was
divided into 10 contubernia, squads of eight men. Within each squad, each man had
a daily duty that would rotate. One would cook. Two would guard. The rest would chop and
dig to build a fort. They worked a full day
of solid manual labor. There was no need for fitness
programs in the Roman army. Their entire life was one
long physical workout. At Alesia, the backbreaking
effort required for 60,000 men to build 11 miles
of fortification, only using muscle
was not to be enough. Another danger was on its way. Not all the Gaulish tribes
were trapped inside Alesia. There's another problem. There's a huge Gallic army
of relief heading his way. NARRATOR: With as many as
250,000 Gaulish reinforcements as close as three
week's march away, Caesar had to move quickly. He has to build another
huge wall facing outward. NARRATOR: Having built one 11
mile wall in just three weeks, Caesar had only three more weeks
to construct a second 13 mile wall. 24 miles of wall
in just six weeks, creating the largest donut
shaped fort in history. He's having to fight
inwards and outwards. JAMES DEAN: This is the
hilltop fort of Alesia. And this is where
the Gauls found themselves trapped by Caesar. And in an attempt to stop the
Gauls gathering provisions and fuel, Caesar decided to
build a wall around the outside of the fort, at the
base of the hill. However, the Gauls
have managed to raise an army of reinforcements,
which was approaching from the rest of the country. And so to defend
against this, Caesar had to build a second wall,
a contravallation, which went around the first wall, and
effectively, barricaded himself in between these two walls. And it's from here he
successfully managed to defend the world's one and only
ring-shaped fort with enemies on the outside and
enemies on the inside. NARRATOR: A Roman fortification
was more than just a wall. Layers of obstacles formed an
intrinsic part of the defenses. "Ancient Discoveries" is
investigating the details of this integrated
defensive system, and will also test whether it
was even possible to build such a complicated fortress
in the mere six weeks Caesar had to complete the job. The main component of a Roman
fort was an oak wood fence. Damian Goodburn is one
of the world's experts in ancient wood construction. The felling was
done with axes. People would cut
a V, or a mouth, or a gob where they
want the tree to fall. That's the first
cut they would do. And then they'd go
around the back, and cut a narrower V a little
higher up the back cut, which will eventually end in the
tree falling in that direction. NARRATOR: The next task is
to create the stakes to form the wooden walls,
known as a palisade. The stakes that form a
palisade are called pales. To make pales at speed,
the Romans didn't use saws. They split the timber by
hammering in tapered iron spikes. DAMIAN GOODBURN: It will
split timber quicker as long as you've got
reasonably suitable material. NARRATOR: But a Roman
fortress was more than a wall. JULIET BARKER: When you
were building a castle, the objective was to
put as many stumbling blocks in the way of the enemy. So you would start off, for
instance, by building ditches around the outside. NARRATOR: John Naylor
is using a team of experimental
archaeologists to investigate the rest of the defenses. Today's test,
for these men, is to try and build a section of
palisade and trench the way that the Romans
would have done it. We're trying to work out just
how much this section of eight men can do in a day. NARRATOR: John
can then calculate whether Caesar's 60,000 men
could build 24 miles in just six weeks with the tools
and equipment available. These aren't props. They're not fancy dresses. They are real linen
tunics, real caligae. Everything from their
boots to the tools, is just the way the
Romans would have had it. So this is a serious attempt
at a reconstructive experiment, experimental
archaeology at its best. We've got our two
trenches and a wall. This layout is
specifically designed to stop the enemy being able
to approach that palisade. A palisade on its own, a man
stand on his horse's saddle and jump over. You need the trenches
to make it all work. But that trench at 1.5 meters, 1
1/2 yards, is a difficult jump, and a jump that a horse
isn't going to like to make, onto this. This is deliberately
sloppy, soft. This berm is unsteady
to land on in between. You try and jump from one
end to that middle berm, you end up in one
of the ditches. Of course, a horse is not going
to land on such a narrow gap as this. On into the second trench. This one's finished. Its full size. And it's already starting
to fill with water. NARRATOR: The trenches and
mounds were further defended with 6 foot long
sharpened stakes. JOHN NAYLOR: By heating them,
they get much, much harder, as hard as iron. These are good
improvised spears. Stakes like this, this
long, sharp at both ends, Caesar ordered to be placed
into pits about a yard deep in a sort of
checkerboard pattern in front of the defenses. Then he got even more devious. In front of these, he
got small iron spikes. These he put in shallower
pits, maybe only 7 inches below the surface
of the earth, then ordered the brush would
be poured over the top. The Gauls came running a long,
plunge through the brushwood, and these spikes went
through their feet. They were pinned in
front of the Roman walls, where Roman archers could
easily finish them off. Hideous, nasty, very effective. My style of warfare. NARRATOR: As the
sun sets on Alesia, 12 feet of fully
fortified palisade are up. JOHN NAYLOR: We've got trench,
berm, trench, bank, stakes, palisade. There's no way I'd
want to attack that. NARRATOR: Allowing for constant
skirmishing and injury, the test can estimate how long
it would take Caesar's men to build 24 miles of wall. The answer comes out at an
incredible five weeks and five days. The fort was fully
erected before the Gaulish reinforcements arrived. [shouting] With no hope of resupply
or reinforcement, Vercingetorix surrendered
in just five days. With such an extraordinary
achievement under his belt, nothing could quench
Caesar's ambition. He went on to become
dictator of Rome, and founded the Roman Empire. 3,000 miles away, in
Britain, Mike Loades is investigating the castle
that created a Great Britain. This is an act of aggression. And that is what
castles are for. Castles are tools of conquest. NARRATOR: A story of
ancient mega construction, built not for defense, but as
an aggressive attack weapon. Medieval Britain was
a world of knights, of violence, aggressive
conquest driven by the castle. JULIET BARKER: When we think
of power struggles today, we think of power struggles
between countries. In the medieval
period, its power struggles between little
lords, great lords, and kings and
princes, all of whom are vying to control as
much land as possible. And that the centerpiece
for each lord is to have his
stronghold, his castle. NARRATOR: The battleground
was the nation of Wales. Here, rebel barons were
rebelling against the king of England, Edward I. JULIET BARKER: Edward I was
probably one of the first truly great warrior kings. And his whole reign really was,
I think, defined by the fact that he was constantly at war. NARRATOR: Many of the barons
were fighting two wars, one against the king, the other
against the other barons. One of them built a magnificent
castle at Caerphilly. This is Caerphilly
Castle in South Wales. And it's a fantastic castle. It's a classic medieval castle. It was built for man called
Gilbert de Clare, who was a powerful baron in
13th century Britain. Now, 13th century Britain
is a very turbulent place. Everyone's land grabbing
and making their alliances. Gilbert de Clare
was a power player. His big enemy though, was his
neighbor, Llywelyn ap Gruffudd. What Gilbert de Clare
did, is he put this castle slap in the middle of
Llywelyn ap Gruffudd's lands, and sad, if you think you're
hard enough, come and get me. This is an act of aggression. And that is what
castles are for. Castles are tools of conquest. NARRATOR: Gilbert de Clare
was loyal to the king. He thrust Claerphilly deep
into rebel baron Llywelyn ap Gruffudd's territory. Its ability to embed itself
deep into enemy territory obviously depends on its
ability to defend itself. And here you can see that
classic castle defense of the moat. The moat makes it difficult
to get siege engines up to the walls. The moat makes it
difficult in many ways. And you can see there, there is
this riveting, this sheer stone wall, only the side of the moat. So if you do even get men in
there to try to escalate up it, they're like ducks in a barrel. And they can't
scramble out quickly. This is the first moat. This of course, is a drawbridge. And if you're are attacking,
this is going to lift up. And I'm leaving you there. And I'm getting to
safety over here. NARRATOR: Even if Llywelyn
ap Gruffudd's men could get across the moat, more pain
awaited them on the other side. There are aspects of
Caerphilly's defense that are as old as
fortification itself, things like the bastions,
these buttress towers along the wall here. And what they do is, not only
do they strengthen the wall, but by jutting out like that,
they give you enfilading. So with bows,
crossbows, with spears, whatever weapons you've got,
you can shoot across the line. So somebody coming up
to that wall there, there's no safe spot for them. Everywhere along
that wall, there's somewhere where you can shoot
at them or hurl a rock at them. NARRATOR: Even if Llywelyn ap
Gruffudd's troops could avoid the arrows-- If that happens,
then this great iron shod portcullis will come
crashing down to bar your way. NARRATOR: Surrounded
with so much protection, the inner heart of the castle
could be a place of calm. Castles are not just
about attack and defense. They're also for living in. All around this big,
open space would have been stables and
huts for the workmen, for the blacksmiths and farriers
that kept everything going. NARRATOR: But as
they lived in peace, the castle designers always kept
one eye on the prospect of war. You cannot have a
castle without a spring. And this is the well going
down to a natural spring. You must have a water supply
that cannot be poisoned. Otherwise it doesn't matter
how thick your walls are, you cannot withstand a siege. They could last out
here for months. NARRATOR: But Mike's
investigations have revealed a mysterious
problem with castle defense. At first glance, there
seems to be a weak point. It's a universal
feature of castles that they have very,
very thick walls. And what you don't want, is
you don't want where your arrow loop is to be a weak
section of wall, because it would be a very
thin bit of wall there. And the enemy would know to
aim their siege machines, their great big boulders
from their trebuchets to come crashing into these weak spots. NARRATOR: The trebuchet
was every castle's enemy. When the trigger was released,
the 3 ton counterweight dropped, hurling 100 pound
balls over 1,000 feet. These missiles were easily
capable of destroying any weak points in castle walls. But the castle engineers
found a solution. In fact, it's one of the
strongest parts of the wall because the architect has
built this elaborate embrasure. So there are steep
angles coming back here, reinforced by this angle here,
reinforced by this archway. The consequence of that
makes it very difficult for me to shoot my bow. I can't shoot a
long bow in here. Because to shoot a long
bow, I need that much room. To pull up a strong
bow, I need to be able to move it like that. NARRATOR: The longbow
is too big to fit into the embrasure, the gap
designed to reinforce the arrow loop. So the archer
with a longbow, is having to shoot this far away. NARRATOR: Ancient
defenders had to be as good with their weapons as
their engineers were at design. And there are other mysteries. On the outer walls
of Caerphilly, are curious holes set at regular
intervals of about 4 feet. These holes supported a wooden
structure called a hoard that overhung the stone walls. In the Middle Ages,
these planks would lift up. And the soldiers
would be here ready. And they would be crashing
down these great boulders onto the heads of anybody
brave enough to get to the base of the walls. NARRATOR: In so many ways,
Caerphilly, the castle built by Gilbert de Clare, was
absolutely impregnable. In fact, one could say Wales
would not be part of England if not for this mega-fort. Caerphilly's arch rival,
Llywelyn ap Gruffudd, never got used to having an
enemy fortress in his backyard. MIKE LOADES: Caerphilly
was never taken. Caerphilly was here stamping
its mark in the landscape. And in fact,
Llywelyn ap Gruffudd was so angry about Caerphilly. He was so angry with
Gilbert de Clare plonking in his castle and his lands,
that when the young Edward I came to the throne, Llywelyn
refused to pay homage. And that kicked
off the Welsh wars. That's the snub that made
Edward I come into Wales, and build a chain of castles. NARRATOR: Using castle
design such as Caerphilly's, the English under Edward
I stamped their authority over the land of Wales. Within 10 years,
an entire country that had remained independent
for tens of thousands of years, fell to the English. But the great
thing that he did, was to ensure that this wasn't
just an ephemeral campaign against the princes, which is
what had happened in the past over and over again. He was there to stay. NARRATOR: And this was
the start of unification that led to the creation of
the present day United Kingdom. However, mega-forts
were not always symbols of power and aggression. Sometimes they could
be quite the opposite. This extraordinary landscape
is home to one of the strangest and most mysterious defense
systems ever discovered. When the people here
were faced with a threat, they simply melted away into
the landscape, leaving no trace. "Ancient Discoveries" is
investigating a defense that seems to leap from the pages
of a futuristic science fiction movie, the ancient world's
answer to an invisible cloaking device. Not all castles and forts are
symbols of aggressive conquest or power. Hidden in this bizarre
and magical landscape that dates to before the time
of man, lie tiny clues to a completely different
style of ancient defense, invisibility. Central Anatolia, in
modern day Turkey, looks more like a science
fiction movie set than reality. Yet for the ancient
peoples who lived here, the threat of conquest
was very real. BETTANY HUGHES: You
have to look at a map, and you realize just
how strategically significant this
particular landmass is. Everybody had their eyes
on this central area. NARRATOR: The Greeks, the
Romans, the Egyptians, the Arabs, the Ottomans,
every major empire came into conflict with the
Anatolian search for booty, slaves, and blood. Anatolia is a crossroad
in between the east and west, culturally,
economically, and in every aspect. NARRATOR: But the people
here were poor farming folk with few natural resources. JUDITH HERRIN: There's not
much ground to cultivate. There's not much land on
which you can grow grain. NARRATOR: Without the wealth
to build splendid castles, the peoples of the
region of Cappadocia chose another defense, disguise. The volcanic rock is
very easily excavated. And they could dig
themselves houses, and of course, large palaces. NARRATOR: These
palaces and houses were dug over thousands
of years, from 5,000 BC, right through until
the present day. Even now, people still make
their homes in these houses, 7,000 years after
they were first dug. Making this complex the
longest, continuously occupied fortress in history. In times of peace,
these tunnels could be used to live normal lives. ALI KARATAS: They started
to organize their stables and their places
where they could cook, and the kitchens,
and the wine cellars. NARRATOR: But when danger
appeared on the horizon, from their high vantage
point known as the castle, the people here could retreat
through a 30 mile long network of tunnels, and disappear. The immensity of this labyrinth
was just one attribute. The Cappadocians had
subterranean treasure rooms, vaults, where they
kept their valuables. An attacker often couldn't
even get into the complex because entrances
were invisible, looking so much like the
rest of the mountainside. JUDITH HERRIN: It would have
been very difficult to attack them. The entrances were
not very obvious. There was no way people would
know that there was such a mass of underground connections. They wouldn't have known
that there was any wealth. The people could hide
in these structures. NARRATOR: They turned deception
and disguise into defense. 7,000 miles away in the
mysterious ancient land of South America, the ancients
turned the tactic of deception into aggressive counterattack. Around 600 AD, the
Mayans developed a tactic for defending their
own mega-forts. And it involved hiding a
colony of stinging bees in dummies, made up to look
like soldiers defending the structure. An ancient Mayan text
known as the Popol Vuh explains the tactic. "They made mannequins. It was as if they
had made people. Next, they lined them
up on the parapet." And somehow or
other, they would they would coax a colony
of bees into the head. And these would be
mounted on the ramparts of the fortifications. NARRATOR: The Mayans would place
these human-looking bee bombs on and around the fortress. The idea is that an attacking
army would come charging in. And when they swiped
at the bee bomb, thinking it was a Mayan soldier,
the bees would get nasty. As soon as, of course, they
hit it, it should shatter. And then all the
bees would come out. When they get aggressive,
they don't differentiate between anybody. It would be, I
suppose, like climbing into a bucket of barbed
wire that would chase you. It's pretty unforgiving. And one hive of bees smashed
down amongst the enemy would give you quite
a wide area of panic. NARRATOR: Richard Windley wants
to know how the bees will react to being attacked. It's difficult to know just
quite how aggressive they'll be. They may simply
be disorientated, or they might actually
be quite aggressive. I mean, it's going to be
me that's going to actually be striking the head. So if I turn and run, then
it will be for a good reason. NARRATOR: There
is one difference. RICHARD WINDLEY: We'll
have protection on. Whereas the soldiers who were
attacking these fortifications would be wearing not
very much at all. NARRATOR: But even a modern
beekeeper suit is no guarantee. Sometimes you
get bees that are more intelligent than others. And they realize if they
can't get in at the top, they'll get in at the bottom.
And if your ankles are exposed-- I've had them change my
shoe size a few times. Can you tell us the horror
stories after we're done? [laughs] NARRATOR: For safety reasons,
Richard is performing the test in daylight. But a night attack would have
given the trap the best chance of working. RICHARD WINDLEY: One can
imagine that that sort of flow of adrenaline, the
apprehension going into battle for the first time, they would
be like a sort of hair trigger. They'd just be waiting
to whack something. They'd be waiting
to actually attack. NARRATOR: At first, the attack
looks like it hasn't worked. The bees stay around the head. Bees only become
airborne and active within a certain
temperature window, depending on the species. RICHARD WINDLEY: Start
to get their bearings, I think they will be
a lot more airborne. NARRATOR: But soon the bees
start to warm up, and take to the air. This is still sort of
reasonably intimidating, actually. If I was just stood here,
with bare chest and bare head, I think this would
be pretty scary. I mean, I'll be out of here
fairly quickly I think. I wouldn't want to hang around. NARRATOR: But Richard's
protective clothing is protecting him from
more than the first sting. Of course, once one of
these things has stung, and that scent
gets into the air, then the whole
thing will wind up. And they'll get more
and more aggressive. NARRATOR: As with
all bio weapons, there is an element of
luck to the defense system. The night could not be too cold. Plus the bees would need
to start stinging in order to get more bees aggressive. Although there is an
element of chance, any defense is better than none. And the bee hive hats
would have complemented other regular defenses,
such as strong walls and human sentries. But there is a weapon from
the ancient world that blasted its way through cold and luck. It was unstoppable. It fired 1,500 pound
balls over a mile. "Ancient Discoveries"
will fire a replica of this ancient cannon
for the very first time. The stakes are high. No one has ever
fired this mega-gun. And nothing even like it
has been fired for hundreds of years. Will it destroy a 3 foot thick
replica of a mega-fort wall, or will it just
plain destroy itself? that had ever been built In was fired to devastating effect
in one of the most important sieges of all time. It was built by
the Sultan Mehmet, to destroy the mega-walls of one
of the largest, longest lasting fortresses in history,
Constantinople. To understand why
the great sultan went to such extreme
measures, researchers are piecing together evidence
to explain why the city was so important to him. Evidence that stretches
back thousands of years to the great empire
of the Romans. In 300 AD, the
emperor of Rome was one of the most important people
in all history, Constantine. What sets Constantine apart
from previous emperors is that he was the
first Christian emperor. Constantine stamped
Rome onto Christianity, and stamped Christianity
onto Western Europe. NARRATOR: Without him, it is
possible that Christianity would not have become the
great religion of Europe and the Middle East in
the first millennium, and one of the most important
world religions today. But Constantine had a problem. During the fourth
century, Rome was threatened by barbarian
tribes from the north. Constantine decided that the
struggle of defending Italy wasn't worth the candle. NARRATOR: Constantine moved
his capital from Rome 800 miles east, to the city of
Byzantium, and named the city after himself, Constantinople. And finally, Constantinople
became the successor to Rome and the Roman Empire. NARRATOR: A new Rome was born. The Roman Empire
wasn't over when they moved to Constantinople. It had just regrouped and
moved to a stronger position. NARRATOR: The secret
of its success is its location,
surrounded by water on two of its three sides. But the new capital
had a strategic flaw. On its rear side it
just has this very flat, undulating country. So what the
Byzantines have to do is they had to develop massive,
monstrous walls in order to protect themselves. NARRATOR: A large, inner
wall provided elevation from which to shoot arrows,
larger catapults, even cannon. Beyond this, layers of
moats and lower walls provided further
lines of defense. Nick Hall, keeper of artillery
at the Royal Armories in Britain, has
traveled to Turkey to examine this vital
historical record. By the addition of a
moat and subsidiary walls, as we have at Constantinople,
you've got defense in depth with a very good chance-- as long as you've got
enough defenders-- of keeping the enemy
at a safe distance. NARRATOR: And between each
wall, a gap called a peribolos. If attackers could make
it past the first wall, they would be caught in
a killing zone trapped between the two cliffs of stone. So dominant and defendable where
these walls that no army was able to capture them
for over 1,000 years, four times longer than the
United States of America has even existed. If the forces
were evenly matched, and there was plenty of
food within the city, it could hold out
practically forever. NARRATOR: But by
the 15th century, hundreds of years after
they were first built, the world was a very
different place. A new emperor, also
called Constantine, was on the throne
in Constantinople, by now, a fully Christian city. But to the south, a new religion
was growing in power, Islam. Islam had conquered
most of the lands around Constantinople, leaving
a tiny island of Christianity surrounded on all
sides by Islam. JUDITH HERRIN: They had
managed to encircle it. They controlled all the
eastern coast of the Bosporus. They controlled the
hinterland in the west. They could put a complete
cordon around the city. Constantinople was the
last Christian outpost in the east Mediterranean. NARRATOR: One of the tribes
that had been converted to Islam were the Ottomans or Turks. The Turks were a central Asian
tribe that due to infighting and rivalries and
population pressures, expanded to come west, finding
the borders of the old Roman Empire. NARRATOR: The leader
of the Turks in 1450 was the Sultan Mehmet. He'd formed the idea
that Constantinople would be the crowning
glory of his sultanate. And he wasted no
time in preparing, in his mind, how he would go
about this great undertaking. NARRATOR: Mehmet was not
to be underestimated. Being dynamic, aggressive,
enthusiastic, ambitious, he was obviously going to get
into action as soon as he'd gathered his forces. NARRATOR: He could also tap into
the Islamic concept of jihad. Islam is an
expansionist religion. That was the message of
the Prophet Mohammad, to go out and spread that
word, just as Christianity is an expansionist religion,
sending missionaries all over the world. He sincerely believed it
was his duty as a good Muslim to take the Christian
city of Constantinople. NARRATOR: Mehmet began
preparing for war. He wasted no time
preparing his huge army. NARRATOR: Behind their wall,
the tiny Christian population of Constantinople
watched helplessly as thousands of Muslims
rallied to the call to arms. NICK HALL: There was a
sense of impending doom. The attack was coming soon. And they didn't know if they
would be able to resist it, despite their splendid walls. NARRATOR: And this
was Mehmet's problem, how to conquer
walls that history had shown to be unconquerable. The ambitious and
ingenious sultan turned to new
technology, the cannon. What Mehmet, the
conqueror, did, is he employed a Hungarian
gun founder called Urban. NARRATOR: Urban proposed using
a new Western technology, the mega-cannon, also
known as a bombard. NICK HALL: Building a bombard
was a major undertaking. It was right at the limits
of the possibilities of late medieval technology. The technical skill
required was extremely high. This was a new weapon,
and a very important one. But the size of the
cannon was critical. This was in a new league. It was a different
category of weapon. It was something so
ginormous that they didn't know how to defend against it. NARRATOR: Mehmet
had commissioned not just any bombard, but the
largest one the world had ever known. "Ancient Discoveries" is
investigating the power of the cannon that
changed the world. Nothing like this has been
fired for hundreds of years. "Ancient Discoveries" is about
to recreate the explosion that changed the world. largest cannon the world had e ever seen. And "Ancient Discoveries"
is about to fire it for the first time. In 1453, the Ottoman army
led by Mehmet the Conqueror, was waging holy war
against the Christian city of Constantinople, using a brand
new technology, the bombard. NICK HALL: These great
bombards were the super guns of the Middle Ages, the
most powerful weapons on the battlefield. NARRATOR: They would have to be. The walls of Constantinople had
stood unbreached for over 1,000 years. NICK HALL: The walls
of Constantinople struck fear into the
hearts of the attackers. NARRATOR: The cannon was
Mehmet's answer to these walls. This is the very beginnings
of the heaviest artillery that has some chance of destroying
massive masonry fortification. NARRATOR: Mehmet
threw everything he had at the project. NICK HALL: He poured resources
into developing the most powerful bombards he could. NARRATOR: Don
Mansfield is an expert in how to fire these weapons. It's a muzzle
loading piece, that is to say that it's loaded
at the muzzle itself. And when we load
it, it has to go right back into the main powder
chamber at the back here. The ball itself is then
loaded again into the muzzle, and rolled back. We're going to use an igniter
today, an electric match. That will set that off from some
distance up on the hill there. And that keeps us all safe
and sound just in case anything goes wrong. NARRATOR: The gun was cast from
bronze in two sections, which were screwed together. The 40,000 pound cannon required
400 men and 60 oxen just to move it. On the day the cannon
was to be tested, no one knew the
impact it would have. A witness to the
siege, named Doukas, described the mood in the camp. ACTOR AS DOUKAS:
"Public announcements were made to advise everyone of
the loud and thunderous noise which it would make so
that no one would be struck dumb by hearing the
noise unexpectedly, or any pregnant women miscarry." NARRATOR: The immense
power of the weapon could hurl 30 inch 1,500
pound stone balls over a mile. NICK HALL: These
things were so massive, and I think always had
such an awesome power just from the visual,
bulk, and mass. NARRATOR: This made the
cannon a weapon even before it was fired, a psychological one. NICK HALL: Mehmet's bombards
alarmed the defenders of Constantinople because they'd
never seen anything like it before. NARRATOR: But it's
true power was only realized when it let rip. It was a new technology. The Byzantines had
no answer to it. NARRATOR: But has
the power of the gun been exaggerated over
centuries of storytelling? There is only one
way to test this. Build one and fire it. I'm extremely excited because
I love the sight of firing an old cannon. And this is one of the most
interesting ones to replicate. It'll be dramatic. It will look powerful. And I think we'll get
some sense of what it was like to be at the siege
of Constantinople in 1453. NARRATOR: It has been hundreds
of years since a cannon like this was actually fired. This really is a first. It's an amazing piece of
experimental archaeology. NARRATOR: Exactly as 500 years
ago, when it was brand new, no one today knows
how it will behave. Every time it
was fired, he was afraid it would crack because
the force of gunpowder required to throw this
absolutely enormous cannon ball that was bigger than
anything anybody ever seen. And the fact that it could be
thrown such a long distance, that meant that it was a
really invincible power. NARRATOR: "Ancient
Discoveries" has built a reinforced concrete
wall 300 feet from the muzzle. The strength wall is scaled to
provide an excellent comparison to what damage the real gun
would have done 500 years ago. In 1453, the fuse would have
been lit with a live flame. Today, explosives
expert, Sidney Alford, is using an electric
spark to ignite the cannon at a safe distance. The team retreat
out of the quarry. [shouting] Firing 3, 2, 1. [boom] NARRATOR: The cannon rocks
with unbelievable power. The accuracy and
power is devastating. A 4 foot hole is
smashed in the wall, and circular shock waves spread
out from the point of impact, weakening the rest
of the structure. The stone wall itself is smashed
on impact, causing debris to fly back 50 feet. JUDITH HERRIN: It was
only a question of time before one great
cannon ball went in, really smashed a big hole
through which the invaders could climb. NARRATOR: The modern test echoes
the original violent explosion. The ancient writer, Kritovolous,
was witness to the devastation. "There was a
fearful roar at first, and a shaking of
the earth beneath, and for a long way
off, and a noise such as never was heard before. Then, with an astounding
thunder and a frightful crashing and a flame that lit up
all the surroundings, and then left them
black, the rod forced out from within by a
dry, hot blast of air violently set in motion
the stone as it came out. And the stone, borne with
tremendous force and velocity, hit the wall, which it
immediately shook and knocked down, and was itself broken into
many fragments and scattered, hurling the pieces everywhere,
and killing those people happening to be nearby." NARRATOR: But Nick Hall wants
to collect scientific data about the true
power of the impact. Because a cannon
like this has never been fired in our
lifetime, this experiment is invaluable for ballistics
experts and historians everywhere. White stakes are set up directly
in front of the cannon mouth at exactly 50
centimeter intervals so that the exact speed of the
cannon ball can be measured. If we measure the speed
that the ball is going, we can weigh it. We'll then know the
energy in the projectile. We can scale that up to give
an idea of the exact power of Urban's bombards at the
siege of Constantinople. NARRATOR: The cannon is
loaded for a second time. [boom] Again, the explosion
rocks the quarry. Again, the accuracy is exact. Further damage rips through
the Constantinople test wall. But what is the exact
power of the cannon? The ball destroys the sticks
at a rate of 1.2 milliseconds per 50 centimeters. The mathematical formula
for energy of a projectile tells us that a 100 pound ball
moving at 260 meters per second will smash into its target with
1,521 kilojoules of energy. This is greater than the energy
delivered by many modern tank shells. This is a real vindication
of medieval technology. NARRATOR: With careful
placement of his cannon, Mehmet brought the
city of Constantinople to heel in just eight weeks. The fall of
Constantinople in 1453 is a tremendously
significant event. NARRATOR: History
was changed forever. An Islamic sultan had captured
the prize of Christianity, and stood on the
steps of Europe. JUDITH HERRIN: The
conquest of Constantinople became a blueprint for the way
that the Muslims would attack the major centers in the west. And of course, they were going
to be attacked again and again and again. And if they could have
conquered all those cities, they would have
imposed Muslim rule. NARRATOR: And what happened
to Constantine and the city itself? He died in the fighting. So he went to his death
defending the city. And that was a martyrs-- the cause of the martyr. And he gave his life for
Christianity and his city. NARRATOR: Yet Constantinople,
a settlement that had stood for 10,000 years, lived on. Constantinople had a another
life as an Ottoman capital. And it was beautified, and
went into a new phase of life, as a spectacular
Ottoman capital. NARRATOR: From the awesome
power of the Turkish bombard, to the organic early bio
warfare of the ancient Mayan, the battle for the walls
of history's mega-forts has produced some of the most
ingenious attack and defense systems ever known. Whatever the local
needs or resources, the aim has always
been the same, to control the castles
that control the land. "Ancient Discoveries" has
revealed that these battles not only change the lives of
the people who fought them, but their consequences
shaped history. The fundamental
part the mega-fort has played in the
story of humanity, goes further than the bricks,
stone, and iron that make up their facade. The battles for
history's mega-forts created the nations and
world we live in today. [music playing]
