Original subtitles

September, 1943, Operation Avalanche,

Italy's D-Day landings is underway.

165,000 Allied troops storm the beaches in a bid to liberate Italy from Nazi control.

Once on land, they must fight their way through the perilous

mountain terrain and heavily fortified enemy territory.

If the Allies can take back Europe from the south,

victory over the Nazis is within reach.

This will be one of the longest and bloodiest campaigns of the war.

In this series, we investigate the most extraordinary events of World War II

from a brand new perspective, matching rarely seen archive film,

photography from the front line, and declassified aerial

reconnaissance images to their original locations.

We reconstruct the crucial battles

daring bombing raids and deadly terror weapons, which changed the course of history.

Soaring over the battlefields, we reveal the secrets of World War II from above.

9th of September, 1943, a reconnaissance aircraft flies over the

clear blue waters of the Mediterranean Sea in southern Italy.

The onboard camera takes this photo.

Allied HQ are examining the progress of their audacious plan,

a vast flotilla of warships and landing craft

heading straight for the coast of Italy, which is under Nazi control.

By 1943, the tide of World War II changes.

The Nazis still have a stranglehold on most of Western Europe,

but the Allies have liberated North Africa and occupy the island of Sicily.

They now plan to launch a full-scale amphibious invasion of mainland Italy.

The British Eighth Army will sweep in from the south

while the US Fifth Army will land on the beaches of Salerno

and fight their way along the coast to finally capture Rome from the Nazis.

The Allies choose this beach along the coast of Salerno as the landing zone.

It's near to airfields and major roads that will be crucial to help them move inland.

The first wave sets off shortly before dawn and sails

across calm seas towards the small town of Paestum.

But as the troops hit the surf and step onto the golden sand,

they have no idea of the horror that lies ahead.

Archaeologist Tony Pollard investigates a set of ruins along the Salerno coastline.

What we have is a really well-built, well-disguised, perfectly positioned bunker

which will protect soldiers, but also it will kill

men on the beach, in the surf and in the water.

When Sicily falls, Italian morale is at an all-time low

and the fascist government is overthrown.

The Italian military announces its surrender to the Allies

just a day before the landings and vacates the bunkers.

Now, German troops move in, ready to repel the Allies.

The Allied troops that land here face a ferocious opponent

in a place where they had expected an easy ride.

There's a strange kind of teardrop-shaped hollow in the floor.

This must be part of the gun mount.

This is a really small space.

You're not gonna have a big gun in here.

It's not an artillery piece.

It's gonna be a machine gun.

And I'd be using a German weapon like an MG42, a really deadly weapon.

The MG42 is nicknamed Hitler's buzzsaw and fires 25 rounds every second.

It spits out a deadly spray of covering fire

that cuts right through the Allied attackers.

The gunner would have been behind here.

This would be an incredibly busy, noisy, smelly, frightening place to be.

What remains of this bunker today is just the tip of the iceberg.

Below the gun emplacement is an entire underground structure

that gives the Germans a huge defensive advantage.

Going back downstairs, you already feel safer

because you're now really under the beach.

And these concrete and stone structures would provide excellent protection

from all of that steel that's flying around,

be it from bombs or artillery shells or bullets.

The best part of this entire thing is this emergency exit,

which allows you to disappear into the dunes.

And I think this is a point whereby troops

could move out into their positions, spread out,

and from there effectively defend this sector of the beach.

Strongholds like this line the full length of Salerno's 32-kilometer-long beach.

German forces have protected the whole of their front line.

Allied attackers have nowhere to hide.

An army is never more exposed

than when they're coming out of the water onto the land.

And this is just an absolute trap for them.

It's perfectly set up to kill men before they even step foot on dry land.

Thousands of men are killed.

It's absolute slaughterhouse.

Under heavy fire on the beach, Allied attackers

hug the ground as German shells land around them.

Medics and troops desperately try to shelter the wounded.

Without more protection, they'll all be slaughtered.

Military historian Alexandra Churchill

explores the ingenious solution the Allies deploy to help defend their troops.

It's called a landing craft tank.

This extraordinary machine is crucial to the Allied invasion of Italy.

The landing craft tank is interesting

because it's made to operate in shallow water, but it's also made to carry a lot.

The key thing is it can carry tanks right up onto

the beach and deploy them straight into action.

The vessel measures 59 meters long and has a top speed of 17 kilometers per hour.

It may lack speed and stealth, but it is massive

and can carry tons of equipment and machinery.

The concept of these vessels is so simple when you think about it.

I mean, they were around pre-Dunkirk, but as soon as Dunkirk happens,

you know that at some point in the future of this war,

you are going to have to invade mainland Europe.

You are gonna have to get back into Europe to try and defeat the Nazis.

The Allies need to quickly produce hundreds of landing craft,

but by late 1940, British shipyards are at full capacity,

replacing battleships and merchant vessels lost to the German U-boats.

What's fantastic about the landing craft is these are made in sections.

Any old factory that deals with steel can churn these out

because you're just churning out pre-fabricated, really simple blocks of metal.

The Allies don't only mass-produce armored transport vehicles.

They also manufacture military equipment and weapons at an astounding rate.

This is a Mark IV Sherman tank.

It's comparatively light for a tank, so it's nimble, it's quick.

Thousands and thousands of these come off the production line.

One of these landing craft can carry 11 Sherman tanks,

making them a key tool on the road to Rome.

When you are invading, when you are turning up,

first off, this is a way to deliver tanks into the area.

They sail right into the beach, and then the door

slams down, and all of these are just ready to go,

and the front ones can be firing shells at defenses as they come off.

Would I have wanted to be on one of these? Absolutely not.

War correspondent Frank Gillard

is on board one of the vessels that lands on the beach.

We were due to land on the Solano beaches at dawn,

that we'd have a fairly easy landing.

My goodness, we couldn't have been more wrong.

It was the toughest assault landing of the war.

I never came closer to death than the actual landing itself

under the most intense fire on the beaches.

Everybody around you is picked off, and you are the one who manages to escape.

The first wave of the Allied invasion

stalls despite deploying the landing craft tanks.

Allied troops desperately need backup.

Over the course of 48 hours, 84 landing craft tanks arrive,

bringing with them around 200 tanks.

Their first goal is to bludgeon a safe path off the beach.

They pummel the German defenses with their guns,

but German tanks hidden in the dunes fire back.

This beach would have been plastered with

fire, artillery, mortar, machine gun, grenades,

and littered with dead bodies and wounded men.

An absolute horror show.

After the surrender of Italy, a lack of preparation from the Germans

gives the Allies the edge.

If the Germans had totally had their act together,

they should have been able, in those circumstances,

to cut the Allies to pieces and push them back into the sea.

The battle is fierce.

It takes the Allies six days to slowly gain the upper hand

and land enough firepower to secure the coastline.

The cost for the crews on board the landing crafts is high.

Many ships are blown up or sunk.

Despite the odds, the Allies defeat the Germans at Salerno,

but it's clear that getting to Rome will be no walk in the park.

After being hit by heavy losses in Salerno, the Allies capture the port city of Naples

to help them bring much-needed reinforcements inland.

Rome is now just a three-hour drive away with a major highway leading directly to it.

But blocking the Allies' path, running the breadth of Italy,

is a series of heavily defended German fortifications

that cross the treacherous mountain terrain.

The only suitable passing point is through the village of San Pietro in Fine.

In December, 1943, a brutal battle erupts here.

The terrain around San Pietro is a defender's paradise.

Every valley could conceal a German machine gun nest.

Every hill village becomes a potential citadel.

Intense rainfall and rough terrain rule out the use of tanks or heavy armor.

This forces the Allies to walk on foot or rely on mules.

Historian Marco Maria Attarano explores how the battle for San Pietro in Fine

marks a savage new chapter in the war in Italy.

The Germans disarmed the local population

and confiscate all kinds of vehicles, food, and other goods that they can find

to fortify their positions around this area.

This is what is left of the original farming village

that was home to about 1,400 people back in the day.

You can see the ruins here of where the people

used to live and where the cattle used to be.

The Germans turned San Pietro's gray stone houses

and thick stone walls into a fortress.

The fighting that took place in the area was so brutal

and so restless that basically the Allied soldiers

that are fighting start referring to the

valley that lies ahead as the valley of death.

Nazi forces set up fortified positions in and around the town,

including machine gun nests, anti-tank ditches, and minefields.

Among the most feared German defenses are booby traps,

improvised explosives connected to trip wires and barbed wire.

The Nazis make use of every resource at their disposal.

The Germans decide to use all the male local population

as forced labor in order to help the German troops put up all the defensive system.

San Pietro is a formidable obstacle,

but the U.S. Commander General Mark Clark knows the only route across the steep valley

is through the village.

San Pietro was the key to the Lurie Valley.

We knew it and the enemy knew it.

We had to take it even though the immediate cost would be high.

Clark orders his men to begin their assault on the 8th of December.

Alongside them are troops from the 1st Italian Motorized Group.

This is very significant because it marks the beginning

of a new phase of the collaboration between the Allies and the Italians.

The Allies now fight alongside the Italians throughout the region

to flush out the German defenders.

But most of their initial attacks are repelled and they suffer heavy casualties.

Allied artillery returns fire to try to silence the defenders.

Shells smash into the stone buildings, reducing the village to rubble.

Marco explores the local caves where the villagers

shelter in a desperate attempt to escape the fighting.

More than 500 townspeople flee the village

and find refuge in this system of grottoes and caves,

which are then expanded by hand.

And you can actually see the signs and the marks of the tools that were used,

from pickaxes to shovels to even forks and spoons,

and create communication doors between each of these caves.

Living conditions in the caves are dire.

Space is tight and food and drinking water is scarce.

They have a handful of dried figs, walnuts, and wild vegetables to eat from.

The only access to water that they have, it was to collect rainwater.

You can feel their desperation

in what must have been quite a situation to live through.

After fierce fighting, the Allies struggle to gain control

and all attacks on the town fail.

As they sweep for mines, legendary Hollywood director John Huston

is part of a US Army film unit at San Pietro.

His cameras capture these extraordinary scenes

of Allied soldiers fighting in the hills.

The footage reveals the brutal reality of the battle for this small village.

In order to break the deadlock, the Allies bring in tanks.

A battalion of Sherman tanks and a British Valentine

start up the narrow road under the cover of a smoke screen.

But they don't get very far.

German mines and artillery shells soon decimate their numbers.

Of the 16 tanks that set off, only four return.

On the 16th of December, the Allies make one last attack

and the Germans are finally forced to withdraw.

San Pietro is left in total devastation.

Sheer tenacity has won the Allies the high ground, but the cost is immense.

The battle for San Pietro in Fine and the valley below

results in 16,000 Allied casualties.

Around 300 villages are also dead.

This is a costly battle for both the defending Germans, the advancing Allies,

but also and especially for the local population.

In fact, it has been said that for every meter

of the Allied advance, the Allied forces lost one soldier.

It has taken the Allies 10 days to capture this small village,

and an even more deadly battle now lies ahead of them.

After seizing San Pietro in Fine from Nazi control, the Allies face another obstacle.

They must capture the town of Cassino, the linchpin of the Gustav defensive line,

which guards the main road through the mountains.

To take Cassino, the Allies split their forces

with an amphibious assault team landing further north at Anzio.

The plan is to cut off the German supply line from the north

and force them to retreat from Cassino.

On the 22nd of January, 1944, the Allies land in Anzio.

This time, the Allied forces are prepared

for fierce resistance after the carnage at Salerno.

Incredibly, the landings are virtually unopposed,

and the only real harassment is from enemy air attacks.

In Anzio, the Allies achieve the element of surprise.

They successfully land their forces on the shore.

By the end of the day, 36,000 troops

and 3,200 vehicles have been delivered into the town.

The landing catches the German commander, General Kesselring, off guard,

but he has anticipated a deception like this.

Instead of hurling his men against Anzio's beaches,

in three days he seals the perimeter around the town.

As the Allies try to move out, they discover they are trapped.

On the 5th of February, 1944, 13 days after the landing here,

huge explosions suddenly pummel the Allies on the beach.

They have no idea where the shells are being fired from.

It's a mega weapon that can wreak carnage on an unprecedented scale.

The K5 railway gun.

This is one of the largest land-based artillery guns ever built by Nazi forces.

Engineer Zeynab Adegan investigates one of only two of these guns that survive.

This isn't a gun, this is a machine.

This is like a terrifying, huge monster machine.

Wow.

No wonder the Allies were bloody scared of this thing.

Walking up to this gun really makes me in awe of the magnitude of it.

This is one of the biggest and baddest guns.

It's a weapon of mass destruction, essentially.

When fully assembled, the K5 mega gun weighs 218 tons.

It has a 21 meter long barrel that can fire 255 kilogram shells over 60 kilometers.

This gun is a true terror weapon.

With such a huge range, it can be hidden many kilometers away from the beach,

targeting men, supplies and ammunition completely unopposed.

The Allies nicknamed this gun Anzio Annie.

They believe the shells are coming from a single gun,

but in fact, the Germans have two, which they name Robert and Leopold.

Together, they rain terror onto the beaches of Anzio.

They were able to target a fuel dump and that

actually created a fire, which lasted about three days.

The amount of damage it causes is absolutely immense.

It's constantly setting the Allies back.

The sound that this gun would have made when

it went off would have been absolutely deafening.

Allied commanders are desperate to find the mega guns and take them out.

From the Bay of Anzio, they calculate the firing trajectory

back to an area in the hills, 40 kilometers away.

Reconnaissance planes spot two railway guns

and send in fighter bombers to take them out.

The pilots report direct hits on the guns,

so the Allies believe they have silenced them.

What the Germans did very cleverly was actually create decoys,

and essentially they made these guns out of wood.

That really helped to fool the Allies.

The Allies may be in the right area,

but the Nazis have hidden the real Robert and Leopold guns

deep inside a railway tunnel, where they are safe from aerial attacks.

The Allies fail to destroy the mega weapons,

which swiftly return to terrorize the men on the beaches.

Just thinking and trying to picture the amount of

damage it would have caused is really mind-boggling.

Honestly, this gun is a huge testament to the

Germans and their fight during World War II.

The Allies are pinned down and trapped on the coast.

The only way to break through to Rome now

is to launch a direct offensive on the Gustav Line itself.

To do this, they must cross the Rapido River and storm

a near impregnable citadel that stands in their way.

Flying over Southern Italy reveals an extraordinary sight,

the mountaintop monastery of Monte Cassino.

The first abbey of Monte Cassino was established almost 1,500 years ago.

The current structure is built like a fortress.

Its huge stone walls are more than 45 meters tall,

and three meters thick at their base.

Along the top are battlements like those on a castle.

The building stands on an imposing outcrop above the town of Cassino.

It forms the linchpin of the German defensive area known as the Gustav Line.

Even if the Allies make it across the Marshy river

every move they make will be within sight

of the Nazi troops perched on top of this hill.

The road to Rome that runs through the valley below

is deadly, an easy target for Nazi artillery strikes.

Military historian Lynette Nussbacher explores

why it is critical for the Allies to take this medieval fortress.

Monte Cassino is vital ground for the Allies' operations to cross the Gustav Line.

Up here, you can see 50 kilometres in every direction.

When the Allies can feel that monastery looking down at them...

..every window could house a German artillery spotter.

Under the laws of armed conflict,

the abbey should be exempt from military attacks.

The Germans are notorious for war crimes.

The Nazis say there are no Germans up here with binoculars

looking down below.

The Nazis say, "Do not attack the monastery

"because it's a cultural treasure.

" Do we believe the Nazis?

We do not believe the Nazis.

The Allied commanders say the Nazis lie about everything.

If the Nazis really have somebody up here,

we'll all be killed trying to cross the river.

From their observation posts high up on the mountain,

the Germans thwart all Allied efforts to take Monte Cassino.

Over three weeks of fierce fighting, the Allies cross the Rapido River

and battle for high ground north of the abbey.

But by 12 February, the exhausted Allied troops grind to a halt

less than a kilometre from the abbey walls.

The fighting in the hills is savage, unrelenting and hand-to-hand.

Machine-gun nests and booby traps turn every ravine into a killing zone.

The soldiers getting wounded are coming back and saying,

"If only we could smash that monastery, we would be winning.

" And maybe they were right or maybe they

were wrong, but the military logic is clear.

One way to deny that vital ground to the Germans is to smash it.

The Allied troops down in the valley grow to detest the sight of the imposing abbey.

British officer Kenneth Leach serves with the Royal Artillery at Monte Cassino.

You ask the ordinary squaddy in the front line

whether he wanted the monastery bombed or not,

he wanted it bombed because he felt that eyes were looking at him

all the time, and you feel that everything you do is observed.

It was very cold and bleak and hostile.

The winter that the troops experience here in Italy

is cold and it is super rainy.

This is arguably the rainiest winter in recent memory,

and that means the rivers are high, all the low ground is flooded,

everybody is very cold, everybody is very wet.

Despite the cold winter,

the Allies know they have to attack Monte Cassino

again if they want to continue the drive to Rome.

By mid-February 1944, the Allied forces at Cassino are stalled.

The US 5th Army is now fighting the Germans on two fronts,

at both Cassino and further along the coast at Anzio, where they remain trapped.

To break the deadlock, Allied commanders move across troops

from the British 8th Army on the other side of Italy.

The majority are from New Zealand and India.

They include Gurkhas from Nepal, who are specialists in mountain warfare.

The Allies have high hopes for their new ground assault,

but Major General Tuka, who commands the Indian division, is worried.

He believes any new attack on the abbey would be suicidal.

He asks the Allies to bomb the monastery and the area

that surrounds it to protect the lives of his men.

To do this, Allied forces use a state-of-the-art twin-engine bomber.

This is the American B-25 Mitchell.

It is one of the most versatile aircraft of the war

and flies for the first time in 1940.

It measures 16 metres long, has a 20-metre wingspan

and is powered by two 1,700-horsepower Wright Cyclone engines.

Pilot and former Royal Marine Arthur Williams

investigates this legendary bomber, used for the raid on Monte Cassino.

Now, I know I say this about every single aeroplane

I've ever seen or flown, but I do love the B-25.

The Mitchell really was a very stable, good all-rounder.

Very reliable, a steady workhorse, used in all theatres of the Second World War.

The B-25 has a top speed of over 400 kilometres per hour

and a range of over 2,000 kilometres.

Here we are at the nose section.

The first thing that you can see, really, is just how much perspex there is.

They're great for visibility, but I reckon for any crew members

in the front there, you'd feel quite exposed.

Quite unique for the aircraft as well is the fact that it's a nose-wheel aeroplane.

The third wheel on most World War II aircraft is positioned at the rear.

The B-25 is one of the first planes where this wheel is positioned at the front.

This comes with huge advantages for the pilots operating the aircraft

because it's just one less thing to have to worry about.

It's much easier to handle a nose-wheel aeroplane on the ground,

landing, taking off, taxiing, with the third wheel being at the front.

This plane needs a crew of five people to fully operate.

Here we are in the entrance compartment of the B-25 Mitchell.

As you can see, it's a very confined space.

And the thing that you notice straight away

is that to access any part of the aeroplane, you've got to be about this big,

because you've got to crawl through loads of different little cubbyholes

to get to the back of the aeroplane, to get to the nose of the aircraft.

The only two people that get relative comfort in

accessing their station is the pilot and co-pilot.

These planes are popular with their crews.

The cockpit of the B-25 Mitchell,

I'm sat in the second pilot seat here, or the co-pilot seat,

and really, the first thing that strikes you

actually is a really comfortable place to be for a pilot.

The display of all the instruments is just as you'd want it to be.

You've got fantastic visibility out of all of the cockpit space.

Many of the pilots loved this aeroplane because it was easy to fly,

and they also say that it could take a hell of a lot of punishment too.

This hard-hitting strafer aircraft has 12.50-calibre machine guns.

It becomes the most heavily armed aircraft in the world.

As a bomber, it can carry a payload of over 1,300 kilograms.

Alongside the B-17 Flying Fortress and the B-26 Marauders,

the B-25 will deliver the bombs to obliterate Monte Cassino.

Allied high command agonises over whether to destroy the Abbey.

But on 14 February 1944, an aerial reconnaissance plane flies low over the building.

The crew claim to see German uniforms and a radio mast.

Their report seals the Abbey's fate.

On 15 February 1944, 256 bombers take off.

The planes drop over 500 tonnes of high explosives

and incendiary bombs directly onto the Abbey.

The raid turns the Abbey into a shattered ruin.

But the bombing has unintended consequences.

The bombing of Monte Cassino creates an unexpected problem for Allied forces.

When we blasted the monastery on Monte Cassino, we created rubble.

The whole mountain was topped with this rubble.

And that turned the mountain into excellent cover for the defenders.

The Germans wire and mine the area, while troops hide amongst the rubble.

It's really easy with hindsight to say

that the Allies made the Abbey worse by bombing it.

But based on what they knew at the time,

it is perfectly reasonable, from a military point of view, to bomb the Abbey.

It turned Monte Cassino into a moonscape.

Failure to coordinate the air raids with the land forces

magnifies the chaos on the ground.

It killed Allied soldiers and killed Italian civilians and didn't kill Germans.

So it's not that this raid is not justified or justifiable.

This raid was not done properly.

Tenacious fighting continues.

The Germans put up fierce resistance, repelling two more attacks from the Allies.

From their foxholes,

the German defenders send deadly shells raining down on the Allies.

On the 15th of March, Allied planes take to the skies again.

This time, they bomb the town of Cassino

and reduce it to rubble to flush out the German defenders.

But just like the Abbey, the Germans fortify the ruins.

They prostrate the Allies at every turn.

Inside the ruins of the Continental Hotel, they hide a tank destroyer.

It takes out everything that moves around it, stopping the Allies from advancing.

On 11 May 1944, Allied forces launch a massive attack

on a 30-kilometre section of the Gustav Line.

The heavy bombardment and lessons learnt from previous

failed attempts mean that this time, the plan works.

Polish troops spearhead the final assault on the Abbey.

They fight hand-to-hand with the remaining German defenders.

On 18 May 1944, five months after the first attack,

British and Polish soldiers finally storm the Abbey

and raise the Union flag alongside the Polish flag in the ruins of Monte Cassino.

This effort is a real Allied effort.

Everybody has come to fight in Italy

because everyone needs Italy liberated and Germany defeated.

Allied Sherman tanks now roll through the shattered town of Cassino.

The road to Rome is finally open.

As the Allies break through the Gustav Line, the German 10th Army retreats.

US General Mark Clark is tasked with cutting them off.

His forces have now broken out of ambush and should be able to capture the Nazis.

The senior American commander in theatre, Mark Clark,

has the opportunity to encircle an entire German force

that will be denied to Hitler for defending Italy.

All Mark Clark has to do is encircle them.

But General Clark is very keen

that if anyone is going to be seen marching into Rome,

liberating Rome, at the head of an army, it's going to be him.

Clark ignores orders to cut off the retreating Germans.

He heads straight for the capital.

In doing so, he allows the German 10th Army to escape.

Jubilant crowds celebrate the arrival of the

Allied forces and Clark's Fifth Army Corps.

As Sherman tanks and army jeeps storm past iconic landmarks

that include the Colosseum and the Piazza Venezia,

Clark and his men encounter little resistance.

Their actions make Rome the first European capital

to be liberated from the Nazis on 4th June 1944.

The drive to Rome and the struggle for Monte Cassino

has resulted in around 55,000 Allied casualties and 20,000 Germans killed or wounded.

The cost in lives is immense.

Thanks in part to General Mark Clark's premature quest for glory,

the war in Italy drags on for another 11 months.

But in their bitter struggle, the Allies have liberated

huge territory and learned many important lessons.

The battle for Rome also diverted many critical

German divisions out of the rest of the continent.

Two days after the liberation of Rome,

news arrives of the successful D-Day landings in Normandy.

Ultimate victory in Europe is in sight.