In 1940, our nation was fighting for its life.
Hitler's Germany was determined to invade our islands
and all that stood in the way were the men and women of Britain.
Now a team of experts across France and Britain
are uncovering fresh evidence of their incredible struggle.
We're going to dig up secrets buried for 70 years
to reveal stories of heroism from Britain's most perilous year.
This is Lymington on the south coast of England.
How are you? Nice to see you.
'I'm here on the trail of the Battle of Britain.'
Nice to see you. How are things? Nice to see you. Hi, Dave.
'By the summer of 1940, Hitler's forces had conquered France and were now at the English Channel.'
Britain's battle for survival was about to be waged in the skies above our homes.
The story of the Battle of Britain doesn't start over land,
as you might expect, but here at sea off the Isle of Wight.
Divers Rob and Dave are joining our team.
We're on the hunt for evidence of the Germans' first major attack on 8th August, 1940.
Total time on the bottom about 35 minutes.
Total dive time about one hour.
An hour. So really, 25 minutes spent decompressed.
For an invasion to succeed, the Germans had to first control the skies.
Standing in their way were a small band of RAF fighter pilots who were to become known as The Few.
It's a lot of gear, guys.
If it leaks, it's my fault.
Are you in?
What do you think the visibility will be like today?
We're hoping it's at least ten metres.
OK. Even 40 metres down?
Oh yeah, yeah.
To lure the RAF into battle, the Germans targeted British ships in the English Channel.
One unlucky convoy, codenamed Peewit, was about to experience the Blitzkrieg first hand.
Joining us on board is historian Andy Saunders,
who's brought once-secret documents that tell the story of that day.
What would have been the effect on the crews?
They would have been terrified, frankly.
This was the first sort of attack like this they'd experienced
and the noise of the Stuka dive bombers coming down,
the screaming noise, plus the whistling noise of the bombs...
WAILING SIREN
..all hell had broken loose.
And these were just falling amongst the ships
and just the concussion and the shrapnel and the smoke
and the columns of water, you know, it must have been horrendous.
Our skipper, Dave Wenders, has been diving these waters for 30 years.
The wreck will start to show in a few seconds.
Now we're running over it. OK, Derek, go.
Rob and Dave are going to be diving on one of the ships lost that day.
I mean, in a sense, you are going back to 1940.
I mean, it hasn't seen the light of day for 70-odd years. That's right.
So we're all set.
Our divers are hoping to find evidence of the German attacks,
and I'm really keen to see if it ties in with Andy's secret documents.
Go.
What was going on in the convoy itself?
Well, there was one ship in particular that is specifically of interest
and that was HMS Borealis, which is this ship here.
It had actually been converted into a tug for barrage balloons
and the idea was that these vessels would tow a barrage balloon over the convoy
and therefore the convoy would be protected from air attack.
That was the theory. That was the theory. Right.
But unfortunately, the flaw in the plan, of course, was that these balloons were filled with hydrogen,
so what happened was that the German escorting fighters
swept down ahead of the dive bombers
and just shot these balloons down using incendiary ammunition
and suddenly there were four flaming balloons falling out of the sky.
By the end of the day HMS Borealis would be on the seabed
and that's exactly where our divers, Rob and Dave, have reached.
They are now looking for evidence of the German attacks.
What's really interesting is that the captain,
Lieutenant Arthur Hague, had with him a camera, incredibly.
He recorded the scene and if you look here, you can see all the debris.
This is after the Borealis had been attacked.
Yeah, the mast shattered.
The mast is down across the wheel house. If you look on the deck...
Shattered doors. ..the doors, and you can just get a sense of the chaos
and here's Arthur Hague sitting rather forlornly on a bollard just surveying the wreckage.
Up above, RAF fighters tried to clear the sky
of now upwards of 150 German aircraft hell-bent on destroying the convoy.
This was just absolute chaos. There were planes everywhere,
aeroplanes falling on fire,
aeroplanes falling apart hitting the sea,
people on parachutes - it was just mayhem.
Everywhere he looked there was mayhem.
30 metres beneath us on the wreck of the Borealis, Rob and Dave have found telling evidence as to why
the ship was finally abandoned by Captain Hague and his crew.
The barrage balloons had become the ship's downfall.
These hydrogen cylinders, which were used to inflate the balloons had been hit, leaking explosive gas.
The Borealis had become a ticking time bomb.
That day, 8th August,
seven ships would be sent to the bottom of the sea.
Amongst the twisted remains of HMS Borealis
Rob and Dave have found something remarkable, an object that for me
really puts a human face on the story - an officer's teacup.
Look at that. A bit of rubbing on the base of this cup and what have we got?
A naval anchor, Staffordshire,
leadless glaze.
A good old-fashioned naval teacup.
Well, on the morning of 8th August,
somebody may well have had a cup of tea from that not knowing what was to come,
and by the end of the day, that and the rest of the ship was on the bottom.
There's no doubt that the Peewit disaster represented a huge material cost in terms of shipping,
but there was another cost, a cost borne not at sea, but, crucially, in the air.
14 RAF pilots were lost without trace.
Now planes could be replaced, pilots could not, and it was perfectly clear that if those sort of losses
were continue, the Battle of Britain would be over almost before it had begun.
This remarkable unseen colour film shows the pilots and fighter planes
which took part in the air battles over convoy Peewit.
This was 601 squadron, who were known as "the Millionaires",
due to their wealth and privileged backgrounds.
To find out more about the pilot who shot this film,
I'm travelling to Cornwall on the trail
of one of the Battle of Britain's most heartbreaking stories.
This is Willie Rhodes-Moorehouse, an accomplished RAF fighter pilot
who had seen action in the Battle of France.
This is Willie's brother-in-law, Dick Demetriadi, a fellow pilot from the Millionaires' Squadron.
I'm here at the family home to find out what happened to Willie,
Dick and the woman who was at the centre of both their lives.
Amelia Rhodes-Moorhouse, Willie's wife, was Dick Demetriadi's sister.
Young and beautiful, Amelia had been approached to play the lead
in the Hollywood blockbuster Gone With The Wind.
Willie and Amelia lived an enviable lifestyle of summers spent in the south of France.
It seemed they had everything and yet, within weeks,
the Battle of Britain would tear their lives apart.
The extraordinary thing about this family is that they really did record absolutely everything.
This really is a unique window on that momentous year.
Every single picture
has been annotated.
Now then, here we are.
A picture of William in his flying boots, immaculate-looking uniform.
This is Dick Demetriadi.
This is the high-end of pre-war society at play
and, as this records, at war.
Here we are, July 1940.
We're right into the meat of the Battle of Britain.
August 1940.
August the 12th to the 16th.
Now this is a truly remarkable picture.
A photograph of Amelia and William
looking absolutely broken and forlorn
and the caption reads simply,
Amelia and William when they had arrived.
He had to break the news about Dick to his father and Amelia,
that he had failed to return from the day before.
I mean, this is an extraordinary record.
It's warts and all on one particular family.
Many families would have shied away from taking a photograph of two people clearly stricken with grief.
Amelia has just heard the news that her brother isn't coming back.
William has lost his best friend
and in a very matter-of-fact kind of way it's recorded,
as is everything else in this extraordinary collection.
In mid-August 1940, the Germans escalated their attacks.
They targeted our ports and RAF fighter stations to try and strangle our last lines of defence.
Amelia's brother, Flying Officer Dick Demetriadi,
had been killed on 11th August in this new phase of the Battle of Britain.
He was just 21 years old.
This is where Dick Demetriadi was shot down, out there at sea
just off Portland Bill off the south coast of Dorset.
The battle that raged in the skies above me on 11th August, in which Dick played a full part,
was one of the most significant of the Battle of Britain,
it was certainly the most ferocious up to that point.
The object of German activity was the naval base below me in Portland.
Accounts at the time describe hundreds of planes in the air.
But there's one plane in particular which I think is worthy of special interest.
It is an RAF Hurricane and it crashed just out there behind Chesil Beach in the lagoon.
Aviation archaeologists Steve Vizard and Gareth Jones are about to
undertake the most challenging aircraft dig they've ever attempted.
Their goal is to recover and preserve pieces of the Hurricane
of Flying Officer John Cock,
who bailed out of his stricken aircraft during the same battle
in which Dick Demetriadi lost his life.
The reason the team's digger is on a barge is because the Hurricane
crashed into water, hence the need for a floating machine.
To add to their headache, the water is tidal and at best only half a metre deep.
The other problem is that it's in a World Heritage Site.
We've got an eight tonne machine on there. An eight-tonne machine.
The pontoon weighs about eight tonne as well.
We're trying to float 16 tonnes on half a metre of water.
And we've probably got 30 centimetres to play with
if we're lucky. That is it.
With such little room for manoeuvre,
the team need to use the incoming tide
to have any chance of reaching the crash site.
There's not a lot of draught there, is there?
No. That's about half a metre, but the problem we've got here.
The inrush of the tide has gone up.
This is the last spring tide of the year and if we get stuck up there, we could be there all winter!
So it's now or never, isn't it? It is now or never.
It'll take our floating digger
several hours to reach the Hurricane crash site,
which lies six miles up the Fleet Lagoon
behind the shingle bank of Chesil Beach.
Most of us tend to think that the Spitfire actually won the Battle of Britain,
but twice as many Hurricanes took part,
shooting down more German aircraft than Spitfires and ground defences combined.
And the Hurricane we're trying to recover has a particularly rich history.
Our team have identified the crash site and start to find small pieces of aircraft,
but the readings show that there are even bigger pieces buried deeper in the mud.
As Gareth and the team continue their hunt,
I'm meeting Steve on the shore to find out more about the site
and the story behind the crash.
How important is this aircraft in terms of those that are left to recover? How unique is it?
Well, it's unique in as much as it's probably one of literally a handful,
fingers of one hand, Battle of Britain sites that are still left in the UK.
The Chesil Beach crash site is doubly important because of the history that goes with it.
The RAF pilot, Flying Officer John Cock, was the first Australian
ace of the war, having already shot down ten German aircraft.
Steve, tell me a bit more about John Cock.
He arrived with the rest of 87 Squadron just really as the battle was reaching its height.
He sort of joined in the battle around about 10.30, 10.45.
He shot down a Messerschmitt and then was attacking a Ju 88,
but one of his guns had jammed and was attacked himself by another Messerschmitt.
I was attacked from below by apparently the same aircraft
who came up underneath
and put a burst through the side of the cockpit
as I was pulling away to the left.
And the engine started to run pretty rough and smoke and catch fire, so I decided it was no place to be.
The instrument panel was shattered,
the engine was obviously hit because it started coughing and spluttering
and he turned the aeroplane upside down and pushed himself out
by putting his foot on the control column. So he bailed out around here, over here?
Just over there at Portland, but at least he got out.
That's the main thing.
The team are hoping for some big pieces of wreckage,
as an eyewitness to the crash said that the Hurricane hit the water
from a shallow glide.
Lying in the mud is the team's most prized find so far,
a compacted mass of over 200 bullets.
You can still see them in the links.
They are in quite good condition.
In a dogfight, the Hurricane had enough ammunition to fire for just 13 seconds.
That August, Hermann Goering, the head of the German Air Force,
was confident that the RAF was a spent force,
but the reality was very different.
That month, The Few shot down twice as many planes as they lost.
Among those shooting down German aircraft in August
was Willie Rhodes-Moorehouse from the Millionaires' Squadron,
who already had nine kills to his name.
Willie was also flying Hurricanes in the Battle of Britain
and we've unearthed film shot from his actual plane during combat.
This remarkable footage is what Willie saw as he fired
his guns on German raiders attacking southern Britain.
At our Battle of Britain Hurricane dig in Dorset,
the pontoon and excavator are now in position
and the team are ready to go.
The tide is also perfect.
It's now or never.
The underwater crash site has been marked out with four bamboo canes.
It's great to know that we are on top of it.
Some of the earlier finds that came out, at least we know we are in the right place.
What will be interesting is to find out how much of it actually survived.
Right then, fire it up. Let's go.
I've seen a few digs in my time, but this is new for me.
The excavated mud is placed on a specially built grid
where the team will sift through it for pieces of the aircraft.
Right, fellas, see what you can find.
Do you want to push it through the grid, Jeff?
It's messy work, but we don't have long to wait.
It's our first piece.
And bigger bits aren't far behind.
There we are. Wow! What do you think that is?
Gareth, have a look at this. Slowly.
This is the first major piece of the Hurricane that we've found.
It's part of the plane's internal structure.
You might say its skeleton, which connects the wings to the fuselage.
This is quite an impressive piece of the airframe actually.
Is this aluminium? Aluminium, it is actual silver paint that was put on there.
For me, this is really special.
It's a genuine piece of a Hurricane that fought in the Battle of Britain.
Can you give me an idea, Gareth, where on the aeroplane this comes from?
This is where the actual pilot sits.
This is the main spar that would sit underneath the pilot.
So was it running along the aeroplane? Along the wing line. OK.
How much of an aircraft survives
depends on the angle and speed it's travelling when it finally crashes.
Even in low-speed impacts,
which might look catastrophic, much of a plane can survive.
But what is becoming apparent on our dig
is that the Hurricane did not survive the impact
as well as the team had originally thought.
Here we are. What do you think that is? A coolant pipe.
Steve is worried because it is so badly bent.
I think it is possibly not quite such a shallow glide after all.
I don't think it was a 30-degree slide into the water.
I think it was probably a bit more 45 because it is not coming out in huge lumps,
as you perhaps would expect a low-speed impact. Yes.
They are big bits, obviously, as you can see. Yeah, absolutely.
Nothing much? No.
Because the Hurricane has broken up more than he expected, Steve is going to have to draw on
all his 30 years' experience in aircraft recovery to make sense of the wreckage.
What have you got here, Steve? That's a rudder pedal.
That's the rudder pedal? That's one of the rudder pedals.
What's that? That's the strap that goes over your toe.
Your gloves are cleaner than mine.
If you clean that up, you'll find "Palmer" written underneath.
Palmer? Palmer. If you wipe it off on the back of your gloves.
Oh yeah, there is it.
"Part number 51". Yes.
So that would sit over your boot.
That would sit over your boot. The pedal is there, which has got the...
You'll see the serration. Ah, that's the thing that you grip with your foot. Yes.
So again the last feet to sit in these were John Cock's. Yes.
We are doing well, but as we know, time is against us.
Shall we ramp this up a bit?
We do need to, actually. Yeah. If he takes a quick bucket out of that.
OK. The same place, but deeper.
This is the trouble. This is the problem...
with underwater digging. Because we're not actually in the water, we can't really see it.
We can't see what's going on. We're relying on Nigel, the digger operator, to feel his way.
They do have a kind of sixth sense.
But again, even he, for all his years of experience, is digging blind.
What have you got there, guys?
Oh, look at that.
"Deptford, London, England. Date of manufacture, March 1940."
Well, it was just a few months before it ended up in here.
Armoured glass from the front of the cockpit. Armoured glass.
The armoured windscreen would sit actually in the frame.
You can actually see that's the edge of the glass.
I wonder if that was shattered by the impact
or shattered during the action that shot him down.
We'll never know. Probably the impact as he hits the water.
The armoured glass from the windscreen of our Battle of Britain Hurricane
is followed closely by dials and controls from the pilot's cockpit area.
Next up, is one of the Hurricane's heavy undercarriage legs, which bore
the weight of the aircraft on takeoff and landing.
And then, suddenly, a piece of the Hurricane emerges, which for me,
really captures the fighting spirit of our pilots
during the Battle of Britain like nothing else we've found.
That's the pilot's control column. Yes.
This is what the pilot used to fly the plane, but also to fire his guns.
The last person to hold that was John Cock, almost 70 years ago.
Is that the...? The gun button. That would be on fire.
It's final proof that 70 years ago, John Cock did go down fighting.
The pilot would have held it like that.
"Fire", and "safe".
Two aircraft shot down by that button. By that button.
That's amazing, isn't it? You see this to me, this is when archaeology really comes to life.
We know, we know, the events of that day, they're recorded, but this is a material record of those events
because this was actually there and this is what made it happen.
What's been a real eye-opener is actually being able to see and touch and feel the controls that this man
used while he was up there in the skies above me, battling not just to stay alive,
but to defend Britain.
A nation that was fighting not just for victory,
but for survival, because that's what 1940 was all about.
Our fighter pilots take off to destroy the enemy.
The newsreels that summer were always upbeat, but in reality,
by September, many RAF pilots had been flying continuously for several months,
sometimes scrambling three or four times a day.
Willie Rhodes-Moorehouse was one such pilot.
Many of his fellow airmen had failed to return and now the strain of combat was beginning to show.
This film captures a brief snatch of leave in Cornwall,
a chance to escape the war and spend time with his wife Amelia.
Just a few days later, on 3rd September 1940, Willie went to Buckingham Palace to be presented
with the Distinguished Flying Cross, and as always with this extraordinary family,
someone was there to film the moment when Willie, Amelia, and his mother left with his gallantry award.
But this is the really heartbreaking bit.
Three days after he picked up his DFC,
Willie Rhodes-Moorehouse was himself killed in action
and these are some again remarkable pictures of the crash site.
I think this is quite moving.
"His body was extricated with great difficulty on Sunday,
"September...15th," I think it says,
"nine-and-a-half days after he was shot down.
"His father-in-law, Stephen, got this done and watched the whole proceedings."
Willie's RAF tunic was also recovered from the crash site, a tragic keepsake for Amelia.
In four weeks, the Battle of Britain had robbed her first of her brother and now her husband.
The Battle of Britain had exacted a terrible toll on Amelia,
like many other mothers, wives and sisters across the country.
But this was not the first time aerial warfare had devastated this particular family.
This is where Willie is buried, his ashes were interred
underneath this plaque, which reads very simply,
"William Henry Rhodes-Moorehouse, DFC, shot down in the Battle of Britain
"September 6th, 1940, aged 26". Just 26.
What's really moving though is that it sits within this frame,
and the frame is his father's grave, Will Rhodes-Moorehouse.
He was also a pilot. He was shot down in 1915
in the First World War and for his gallantry was awarded the very first flying Victoria Cross.
These were both men who died at very similar ages united in a passion for flying, but also
with an enormous sense of duty that they should both serve their country and pay the ultimate sacrifice.
Never in the field of human conflict
was so much owed by so many to so few.
All our hearts go out to the fighter pilots whose brilliant actions we see with our own eyes day after day.
Churchill immortalised them as The Few.
Just 3,000 RAF aircrew fought in the Battle of Britain.
Some, like John Cock, were lucky and survived the war.
Dick Demetriadi and Willie Rhodes-Moorehouse
were two of the 544 pilots of Fighter Command who gave their lives that summer.
The heroic few had paid a heavy price defending Britain.
Now, though, it was the turn of the many.
Our nation's civilians were about to bear
the brunt of Hitler's murderous rage in the firestorms of the Blitz.
Subtitles by Red Bee Media Ltd
E-mail subtitling@bbc.co.uk