"'This is the story of a remarkable journey 'that began as the echo of the guns from the Great War died away." "'A French pilot and his cameraman climbed into an airship 'and flew over the Western Front." "'They made this unique film 'and captured with astonishing clarity the aftermath of devastating conflict." "'90 years later, I'm retracing that journey, 'flying on a rather safer airship over that very same landscape." "'And visiting the battlegrounds where such terrible slaughter took place.'" "What would we have seen then?" "It would have been total devastation, very much like a lunar landscape, but with just the awfulness of modern war thrown in." "'I'll also uncover another of World War One's secrets - 'a collection of revolutionary aerial photographs." "'They gave the generals a bird's-eye view of the battlefield." "'Now these images can be brought to life using today's state-of-the-art technology.'" "Three, two, one..." "'And I'll be taking to the air in one of those flimsy early aircraft flown by those brave pilots." "'Like most people, I've always imagined World War One from the ground." "'But seeing it from the air will give me a totally new perspective." "'The trench networks that ran for thousands of miles." "'The epic destruction that the war left behind." "'And the memory of millions advancing to their deaths.'" "The bullets are coming from this side and that side, so what you had to do was to walk through a stream of lead." "'Above all, this is a story of human courage." "'And my journey will end with an extraordinary encounter 'when I meet the daughter of the airship pilot of 90 years ago.'" "What does it mean to you, seeing him like this?" "I couldn't expect seeing my father alive." "'From the intimate to the truly epic, 'here is the conflict in a way we thought we'd never see it - 'the First World War from above.'" "Deep inside the vaults of the French army's film archives in Paris, a unique snapshot of our history has been unearthed." "A 78-minute film which has spent nearly a century hidden from view." "It follows the flight of an airship along the Western Front, the infamous battle line that divided the Allies and Germans during the First World War." "The airship's pilot Jacques Trolley de Prevaux and his cameraman Lucien Le Saint captured a lost world just months after the end of the fighting." "A city with its proud medieval cathedral reduced to ruins." "Battlefields scarred with shell holes where men waited to die." "And ghostly figures, people still holding their street market in front of their shattered homes." "This breathtaking film isn't simply a record of the First World War." "It's a showcase for two of the greatest inventions in modern times - flight and film." "The First World War had brought about a revolution in the technology of the air and photography." "What this footage represents is a marriage of the two to create a vision of the battlefield quite unlike anything that had ever been seen before." "Over 90 years later, I'm about to look down on those former battlegrounds from a modern-day airship." "I'll fly over the same landscape filmed in 1919 to see what remains of the Western Front." "This heavily defended line of trenches stretched for 400 miles from the English Channel down to the Swiss Alps." "The French airship made a series of journeys along that front line." "The story starts at Nieuport on the Belgian coast, a town just 50 miles across the Channel from England, but marking the most northerly point of the Western Front." "Here in the early years of the war, the Belgians flooded the low-lying fields with sea water, slowing the German advance and pushing the enemy inland." "After Nieuport, the airship flew down from the coast, its camera capturing some of the worst killing grounds of the war." "One infamous combat zone was Chemin des Dames." "This plateau in northern France lay between the German army and Paris and saw some of the fiercest fighting in the war." "This footage shows French tanks lying abandoned in No Man's Land." "And enormous trenches stretching as far as the eye can see." "Today, there are very few trenches left in the former battlefields." "This small area of woodland near Wytschaete in Belgium still contains part of the old German front line." "I've come here with archaeologist Nick Saunders, an expert on trench warfare." "How much protection was provided by these trenches?" "How safe could a soldier feel in here?" "Well, they could feel safe from horizontal shrapnel, but they certainly couldn't feel safe from a direct hit or indeed a hit on the other side which blew in vast amounts of earth on top and often buried people alive." " Why did they dig in a zig-zag pattern?" " This was basically for protection." "They found out in the beginning of the war that when artillery shells landed, the blast effect near a trench could go all the way along a trench and kill half a dozen soldiers, so the basic idea of the design was a quick change to a zig-zag, so that only one or two or three got killed" "and the other three, four, five on the other side of the zig-zag were safe." "We're in one tiny section of trench, but it was a vast network on both sides, wasn't it?" "Yeah, because you had the Allied trenches and these were mirrored on the other side by the Germans." "And they have support trenches and communication trenches." "So it just goes on and on and on." "There are literally tens of thousands of miles of interconnected trenches from the English Channel to the Swiss border." "Using exact details from Allied and German trench maps, we can re-create the scars that ran across the Western Front." "An alien landscape of man-made furrows." "Rat runs where men lived, fought and died." "The trenches were not only photographed by the French airship in 1919." "During the war, there had been another revolutionary way of looking at these vital communication lines." "For the first time, commanders would no longer rely on the worm's eye view from the trenches." "Now they could look down on enemy positions." "Photography from aeroplanes would change warfare for ever." "'Today, many of World War One's aerial photographs, the first ever taken, 'are kept safe by the Imperial War Museum in their original wooden caskets." "'Dave Parry, the museum's aerial photography expert, 'has brought me to see these images known as the Box Collection.'" "Look at all of these." "How many?" "In all, about 145,000 to 150,000 remaining." "There were about half a million, but these are the only ones that survive." "What were these pilots looking for as they were flying over the Western Front?" "What kind of material can we see in these incredibly heavy boxes?" " LAUGHTER" " That is so..." "All right, here's one." "Let's take a look at this." "Wow, look at that!" "Now, what are we seeing here?" "What's all this?" "These look like trenches under construction." "Because it's a negative, all the spoil which is thrown up by the trenches looks dark," " but it is in fact chalk." " Chalky soil." " Chalky soil." " In northern France." " That's right." "I'm trying to imagine the British commanders' reaction when the first box of these glass plates comes in and they see for the first time in the history of warfare an aerial photograph of the enemy." "It must have been quite a moment." "It's a revelation to them." "They've never seen anything like this before." "For the first time, they could see the depth of the defences, the number of machine-gun posts, trench mortars." "It was all laid out for them with amazing clarity." "I presume developing these must have been an incredibly primitive business," " given that the conditions are, to put it mildly, far from ideal." " It was very difficult indeed." "Very often, the members of the photo section were reduced to washing them in ditches by the sides of the roads." " And they've survived." "It's our last link with these men and their flying machines." " Indeed it is." "These flying machines were another revolutionary part of the First World War." "For the first time, men took war to the skies." "And I've come to try out one of the original aircraft at the Shuttleworth Collection in Bedfordshire." "During the war, more pilots died in training than in actual battle." "Three, two, one, go!" "And the most dangerous part of all was take-off." "If the engine cut before you got airborne, the plane simply drove itself and the pilot into the ground." "This was an advanced aircraft for its time as it was built in 1917 towards the end of the war." "Travelling in it today is petrifying." "You really do get a sense of the risks taken by the pilots." "Flying these planes over the Western Front was phenomenally dangerous." "You had ground fire coming up, enemy fighters trying to hunt you down." "These early pioneers of aerial photography were men of untold courage." "It's extraordinary to think that when the First World War started, men had been flying for barely a decade." "It was only in 1909 that Frenchman Louis Bleriot had developed an aircraft good enough to fly across the English Channel." "Just five years later in August 1914, four squadrons of Britain's Royal Flying Corps flew back across the Channel to France." "This time, they were going to fight in the Great War against the Kaiser's men." "Britain's first wartime aircraft were a ramshackle collection." "The technology was new and unreliable." "One plane had even crashed before it reached Dover, killing both of its crew." "As for the men who made it to France, flying over the Western Front would carry even more danger." "Now they were targets for German anti-aircraft fire." "And as I come to the end of my flight today," "I can begin to understand why the life expectancy for pilots was actually worse than for men in the trenches." "Well, there we are, terra firma at last." "What an extraordinary experience!" "You know what I felt up there?" " The most amazing vulnerability." " Very much so." " And we were doing this on a beautiful summer's day." "What was it like in winter with fire coming at you from every angle?" "What was it like for them?" "Well, they were a long way up." "They operated over the front lines at over 12,000 feet, so it was cold, freezing cold." "There would be fighters to contend with." "There would be anti-aircraft fire." "There were lots of things to contend with, as well as taking photographs." " Which must have been pretty cumbersome if you had to lean out of this aircraft that far up?" " Indeed." "The camera was big." "The air speed was high." "You've just experienced it." "Although it's an old aeroplane, we were travelling at 100mph, so to hold a camera over the edge steady enough to take a photograph of something 12,000 feet below you must have been hugely difficult." "Despite their primitive and unwieldy cameras, the Royal Flying Corps managed to take hundreds of thousands of detailed photographs." "The results of their work were invaluable for the British generals planning the war and 100 years later, these images still have stories to tell." "Belgian archaeologist Birger Stichelbaut has been digging deeper into the aerial photographs." "I think it's a major overlooked source." "Nobody ever looked at the entity of world war photographs." "Nobody ever looked at using them as a primary source of information." "Many people who study World War One use trench maps." "They look at perhaps some aerial photographs, but one mistake they make is they focus on the area of the battles, but much more happened 40, 50 kilometres behind the front line." "This photograph taken over Diksmuide in Belgium shows how some German soldiers unwittingly gave away their position." "The men's barracks were safely camouflaged under trees, but to relieve the boredom, the soldiers had been gardening." "And to the British photographic experts, the German flower beds were clearly visible from above." "Many of the officers or men on the ground didn't have an idea of how things look like from the air." "On this photograph, we can see a lot of military barracks, in fact, but we can see that something else happened here." "When we go to a detailed photograph of this... ..we can see that these are the barracks and in fact, these are actually flower beds, flower beds that were constructed to make life in this camp more comfortable, to feel more at home." "But the new technology of aerial photography was about to bring devastation to the German soldiers." "Once the British commanders saw the flower beds, they uncovered the barracks and directed the big guns on to the position." "The act of making flower beds really draws the attention towards the site." "This is actually what happened a couple of months later." "Around the area, we can see that the landscape is already peppered with these shell holes and a lot of the barracks have already been destroyed." "The art of interpreting aerial photographs soon became highly developed in the war." "As experts scrutinised each inch of the enemy front line, life on the ground would no longer be hidden." "As the war progresses, you have aerial photography and it completely changes life for men in the trenches because now everything can be seen from above and there's much more accurate targeting." "That's true, but as time went on, different sides decided that they could develop the idea of camouflage, so there was a lot of feint and counter-feinting going on here." "And basically, it was much more developed, the systems were deeper, they were more organised, yet at the same time, the aerial photography from the other side enabled them to take camouflage." " Let me have a look." "You've got some examples of aerial photography here." " That's right." "What do these patterns tell you about the experience of the men who lived and died in these trenches?" "I think it was chaotic and horrific." "The trenches gave a lot of protection." "It was partly psychological." "But it was constantly trying to outwit the enemy, outthink the enemy, outdig the enemy." "There's a German side, and on the British side, you were constantly finding new trenches being built, new connections being made to get troops from one place to another safely." "So, for the ordinary soldier on the ground, there was a psychological dimension to the safety, particularly in a dugout, but in reality, at the end of the day, they had to get out of the trench and go across No Man's Land and that was just lethal." "No Man's Land, the thin strip of ground separating the two armies, turned into a vision of hell after unceasing pounding by heavy artillery." "Villages and towns were reduced to shells." "And the French airship captured this destruction in intimate detail." "Flying over Armentieres on the border between Belgium and France, pilot Jacques Trolley de Prevaux flew so close to the shattered church, he and his cameraman nearly came to grief." "The two men filmed mile after mile of the ruined landscape." "But there's one infamous battlefield you won't find in the footage - the Somme, the place where I'm heading now." "In summer 1916, this 15-mile stretch of the Western Front would see the darkest days in the history of the British army." "And the build-up to this epic battle was captured by tens of thousands of photographs of the German defences taken by British aerial photographers." "Using these images, we can reconstruct a part of the German front line just days before the Battle of the Somme began." "The photos show just how complex the German trenches had become." "A network of interlocking lines and heavily defended redoubts." "Crucially, the Germans also held the high ground, in some cases, just yards above the British positions." "The attack was planned for the 1st of July." "For seven long days before, there was a massive artillery barrage, an attempt to weaken the German defences." "120,000 soldiers assembled in the front-line trenches, ready to go over the top." "These men now sat waiting in the tense moments before the start of the battle." "On the day of the battle, the pilots were out early, photographing the German front lines." "18-year-old Cecil Lewis was one of those flying above the Somme that morning in July." "Years later, he wrote about one of the most shocking things he'd witnessed - a massive explosion just moments before the attack began." ""The earth heaved and flashed." ""A tremendous and magnificent column rose up into the sky." ""There was an ear-splitting roar," ""drowning all the guns, flinging the machine sideways in the repercussing air." ""Then the dust cleared." ""The infantry were over the top." ""The attack had begun."" "Up in the air, Lewis could have had no real idea of what was about to unfold." "On the ground, as soon as the men climbed out of their trenches, the battle plan went catastrophically wrong." "Historian Peter Barton is taking me across a stretch of No Man's Land at La Boisselle, one of the Somme's most notorious killing fields." "We're just crossing the British front line now." "You would have climbed out of a trench here to go into the attack across No Man's Land, so all those German front lines ahead of us would have been erupting day and night for a week and that filled everybody with a tremendous sense of confidence." "You can see that in the testimony and letters. "We're going to do great things tomorrow." And..." " Within seconds of getting..." "Many men didn't make it over the parapet." " Yes, the Germans were prepared." "The moment that barrage lifted, that was the signal for the Germans to start firing." "Across this ground here, at the height of this wheat, they would fire their machine guns at the height of this wheat, so you were being cut down here." "That's why you read so many accounts of people being cut down as if they're being scythed down." "They were being scythed down." "And the bullets were coming from this side and that side." "So what you had to do was to walk through a stream of lead." "And men kept going." "I think that's what the..." "The thing that affects me so much is that the second wave would have seen what happened to the first wave." "The third wave would have seen what happened to the second wave and on and on." "One of the things which a lot of the accounts tell us is that whenever the firing stopped, men could suddenly hear the sound of skylarks and other birds." "We can hear it now, what they would have heard." "BIRDS SING That's right." "There were little windows in that barrage." "The birds just kept on singing." "By the end of the first day of the Battle of the Somme, 60,000 British soldiers had been killed or wounded." "All but a handful of the attacks had failed and the slaughter would continue for another four months." "By the time the battle ended in November 1916, there had been more than a million casualties." "To this day, here in No Man's Land, they're still finding fragments of the lost like this button belonging to the tunic of a French soldier." "A British private, J McCauley, who was assigned to bury the dead, remembered how for weeks afterwards the smell of decay lingered in his nostrils." ""If only the world could see this," he wrote," ""how nearer we would be to perpetual peace."" "McCauley must have known, of course, that he was writing more in hope than anticipation." "Today, it's hard to imagine that this peaceful landscape was the scene of such terrible slaughter, but inside this area of woodland, owned by a local French family, the ground has been left pretty much as it was when the fighting stopped." " What was in here?" " You're walking through a German communication trench, leading to the front line up here." " This path takes us up to the German front line from where they could easily have seen the British." " Yeah." "At the top of this crest, you can see how close they were." "Here is your German front line along this crater's edge." "On the far crater's edge is the British front line, 35 metres away." " They would've seen them very, very close." " They could smell each other's cooking." "What's this down here?" "It looks like a German shell." "This is the most common shell that the Germans used." " That's a large shell." "Is that still live?" " It is, yeah." "It's been fired." "You can tell by the band at the back of it." "The fuse is still on it, that is still live, so we don't kick it." "Let's move on." "Areas like this which, as you can see, there's craters within craters, over 18 months of war, this ground has been thrown up in the air and landed back on top and again and again and again," "and whoever was buried in here is still buried in here." "We know there are many Frenchmen beneath our feet, British and Germans, so this is a mass grave that we're walking on and there's no way these men could ever be found." " And there you have the dead." " That's right." "And that's precisely why this family preserve this piece of ground on their behalf." "'One feature of the Battle of the Somme still stands out among the wheat fields - 'an immense crater right in the middle of what was once the German front line." "'This is a different part of the Somme story." "'The great explosion Cecil Lewis saw from the air 'was really a drama played out underground 'because it was on the Somme 'that the British High Command turned to an old form of warfare - 'tunnelling under the enemy and setting off enormous mines.'" "To create this mine, what did they have to do?" "They started tunnelling several hundred metres back in that direction, in the valley behind, dug down to a depth of about 90, 95 feet, then went under No Man's Land to this point here, planted the mine in two chambers," "and then blew it at a time given by the divisional commander." "What's it like when a man is digging or a group of men are digging their way towards the German lines?" "The tunnelling war was a very particular kind of conflict." "It was private, it was secret, it was in tiny, constricted spaces underneath No Man's Land, underneath the enemy lines." "You're either listening for the enemy coming your way and trying to destroy them underground or you are trying to undermine his trenches." "The closer you get to the enemy, although you're 90 feet down, you have to be ever more quiet, so by the time they've reached this spot, they'd pick out lumps of chalk with a bayonet" "and catch them before they hit the ground, so they couldn't be heard by the Germans." "One of the strange things about this is although they're only working, digging with one candle, they are surrounded by pure white chalk and they became snow-blind in these tunnels." "They had to be taken out of the tunnels until their vision came back again and you'd go back in and it would happen all over again." "If you're tunnelling and you hear the enemy, how do you kill him if you can't see him?" "Well, you can hear him tunnelling towards you." "What you do is, after his tunnel has got close enough to yours, you plant a charge in your tunnel, block your tunnel off with sandbags and then blow that charge." "You either obliterate him or entomb him or gas him underground with gas from the explosion." "Those men are trapped down there." "And if you got trapped underground, your comrades would make every possible effort to find you." "If you are killed underground..." "Try to imagine." "Decay on the surface is bad enough, decay of the human body on the surface." "Trapped within a tunnel, deep under No Man's Land..." "Tunnels are always dug on a slight upward angle for drainage purposes, so the remains of that man would drain back towards the rescue team, if you know what I mean." " So the blood would run through the chalk." " One of the starkest images of warfare I've ever heard." "It's utterly unimaginable." "And anybody who was on top of this in the German positions, they were obliterated in an instant." "Vaporised, these men." "Yeah." "As a result of the tunnelling, this mine and nine others exploded on the first day of the Somme." "This was a war of annihilation, as seen in this Box Collection photograph." "The Somme proved that tunnelling could be devastatingly effective." "The British would escalate their use of mines in 1917 at Messines, an area of high ground, stretching south from the most famous city on the Western Front, Ypres." "The story of Ypres in Belgium has come to symbolise the First World War's epic destruction." "Over the course of the war, the medieval city was pounded relentlessly by artillery fire." "Using data from aerial photographs, we can re-imagine those four long years of bombardment." "When the guns were at last quiet and the French airship flew over the city centre, all that was left of this once-beautiful place were the remains of its 13th-century cloth hall and cathedral." "Pilot Jacques Trolley de Prevaux waved down at people wandering through the ruins." "He then directed his airship towards the battlefields, beyond the city's medieval moat." "Today Ypres has been rebuilt in almost the exact image of what it once was." "Beyond the city, you can look down on the scene of a surprising British breakthrough." "The Messines Ridge is a line of villages stretching for nine miles, on high ground that in 1917 was held by the Germans." "If you look today, there are 17 deep craters now filled with water." "These holes were all made within 30 seconds of each other, with huge amounts of high explosive, 450 tonnes of it planted right under the Germans' feet, culmination of the biggest British tunnelling operation of the war." "These photos show the heavily-defended Messines Ridge before the start of the battle." "The audacious British plan was to dig tunnels for over a year and place mines beneath the German lines." "The would all be detonated at three in the morning, shortly before the infantry attacked." "When the mines exploded, the enemy defences would be obliterated in an instant." "In the early hours of June 7th, 1917, a British general turned to his officers and said," ""Gentlemen, we may not make history, but we'll certainly change the geography." In fact, they did both." "The biggest explosion in the long, bloody story of warfare ripped through this countryside." "Mankind came face to face with his own capacity for destruction." "One by one, the mines exploded, sending pillars of flame into the sky." "The explosions echoed across Western Europe, even rattling the teacups in Downing Street." "Two years later, the French airship filmed parts of this battlefield." "Pilot Jacques Trolley de Prevaux flew over Mont Kemmel, the highest point overlooking the Battle of Messines." "Kemmel offered the perfect viewpoint for the British generals to see if their tunnelling operation would work." "'At three in the morning on the day of the attack, the top brass gathered here to watch.'" "There had been an artillery bombardment, so the Germans were pretty shaken up as it was, but they had no idea of what was coming next." "No, they didn't." "They knew that there was probably a battle coming and they might have expected artillery and perhaps a mine or two, but they had no idea there would be 19 mines in sequence." "That would take them completely by surprise." " That's one reason why the battle was such a success for the British." " That crucial element of surprise." " And this awesome explosive power." " Yeah." "And also, psychologically, they saw the mines exploding and coming towards them, so by the time you get down to the south, by Plug Street Wood," " they'd had a chance to see and hear the others." " In quick sequence." " Just in a few seconds." " There's nowhere to run." " Nowhere to go." "By the time the last one went off, the Germans around there were in complete shock." "Totally paralysed." "They had never heard or seen anything like this before." "I read that the largest part of a German they found after these explosions was a foot in a boot." "I think that was true." "A foot in a boot is probably what they found after the battle, but when we do archaeology here, we find bits and pieces of humans no bigger than a fingernail clipping." " Completely fragmented." " Tiny pieces of bone." " Yeah, miniscule fragments." "That's all that's left of the Germans who were underneath the mines." "To understand the underground attack on Messines, it's best to take to the air." "The craters left by 17 of the mines that exploded look today like pretty ponds on the landscape." "Until you think of how they were made." "Basically, we have three big craters here that have been reincorporated into a rebuilt farm after the war." "They're now part of people's gardens." "And this is the southernmost part of those mines." "They stretch up towards Ypres." "This big one over here." "What's that?" "Is that from a mine?" "That's almost certainly two mine craters because of the huge size of these things." "They've also been incorporated into modern buildings." "In fact, they've been incorporated into a golf course." "Quite extraordinary." "It's also something to bear in mind that almost certainly there are many, many human remains at the bottom of these lakes." "So although they may be landscaped for a golf course or as part of somebody's garden, if you dried them out and excavated them, you'd almost certainly find human remains." "'Below the craters, many of the tunnels are still there 'and relics of the underground war can be found across this region." "'Even today, solid ground can suddenly collapse, 'as one farmer's wife discovered to her terror.'" "TRANSLATED:" "I'd finished cleaning the windows and was taking my ladder to the barn." "I looked down and I saw some weeds." "Right here." "So I came back to get my bucket, but when I stepped here I fell down a hole." "It led into a network of tunnels, the roof of which was just three feet below the farm's foundations." "Waist-deep in the muddy water," "Simone Duleux had no idea of what had just happened or how she'd get out." "TRANSLATED:" "At first, I thought I'd fallen into a cesspit." "Then I had to wait an hour for my husband to get home." "I knew he wouldn't be out forever." "I was already in for a ticking off for staying out too long." "I had to look for her." "I searched everywhere, even in the attic." "Then I changed into my normal clothes and went to look again." "While I was standing by the kitchen table, I looked out of the window and I saw her hand sticking out, just her hand, that was all." "She had her hand up like that." "Then, of course, I ran to find a ladder." "I lowered that in and she was able to get out." "For the men who dug the tunnels, Messines was a stunning victory." "Once the mines had exploded, the British infantry easily overran the German trenches on the ridge." "After Messines, it seemed as if the stalemate was at last over." "The British commander General Haig told his men they were now to wear down the enemy's resistance." "But on the German side, General Erich Ludendorff ordered that every piece of ground lost was to be retaken by ferocious counter-offensive." "It was that determination which created the mud and the slaughter of a place whose name has become synonymous with the sacrifice of World War One." "Passchendaele." "The Battle of Passchendaele would be defined not by trenches or tunnels, but by weather." "The summer of 1917 was one of the wettest since records began." "The French airship would film a stretch of the Western Front that had been turned into a sea of mud and blood." "During the fighting, men were as likely to drown as they were to be shot dead." "Today Passchendaele has returned to what it once was - a tranquil village in rural Belgium." "But the Box Collection photographs show how the fighting in World War One flattened everything here." "Britain and its allies fought for control of the village in an attempt to outflank the German army." "After four months of shelling, Passchendaele was almost wiped off the map." "All that was left were the shattered ruins of the church." "'I've met up with the historian Nigel Steel to find out more about those aerial images.'" " The photographs tell a huge amount of the story." " Yes." "We can learn a lot by looking at the sequences you can find." "This is a nice example here." "This is a photograph taken before the battle begins." "It shows Passchendaele." "You can see the roads from Zonnebeke, going around the top." "You can just see the church in the middle of the village." "And when the battle reaches the top of the ridge and washes over it," " it becomes something almost inconceivable." " Good lord!" " That is extraordinary." " This is something you only see from the air." "You can still see - just - the shape of the road, the remains of the church that sits in the middle." "Everything else obliterated." " And everywhere these shell craters filled with water." "In which men drowned." " That's right." "Carry any weight of equipment, you'd go down." "If you fell into it, often you'd drown, get sucked down." "It was like crossing quicksand." "How many lives did it take to capture small pieces of ground?" "If you wanted to advance a mile?" "Well, over the course of the battle, 275,000 casualties are thrown up as a result of moving from the start line to the top of the ridge." "We're talking about 20,000 plus casualties to gain 1,500 yards, at one point." "And that's for something that looks like a relative success." "When you see this period in September and October, when it stops raining and they're able to go forward and hold the ground, you still incur casualties of around 20,000 per step." "When you say those words nowadays, people find them hard to believe." "You simply wouldn't accept that in a modern war with the British Army." "No, it's inconceivable and it's something which today still makes people shudder." "It sits at the back of your mind as the worst of the First World War." "If you know what to look for, this aerial photograph of No Man's Land contains a secret story - a famous British tank bogged down in the mire." "The crew of nine men inside it found themselves stranded between British and German lines at the height of the battle for Passchendaele." "The tank's commander had a sense of humour and he gave it the nickname Fray Bentos, after a famous tinned meat." "'And now the photograph has helped to pinpoint the very spot where this happened.'" "We're right in the middle of the German battle zone." "Almost smack bang in the middle" " British front lines over here, Germans coming up to here." "The British bring up tanks ahead of the infantry and one tank gets isolated." "Yeah, the Fray Bentos tank ditched in this hollow here." "It ground to a halt." "The problem was that it was in the front line with the infantry, but they were driven back by the Germans, so Fray Bentos found itself way out in front of the British line and it gradually became surrounded by Germans." "Over three days, the guys inside the tank fought off the Germans." "They were on the roof, firing at them, trying to blow them up, they were hit by shells coming over the top." "All they could do was try to make their way back over here, past where they'd come from, to get back to the British lines, which they did." "This stands out because that little group became very heavily decorated." "Two Military Crosses for the officers, two Distinguished Conduct Medals and four Military Medals." "Eight people with a gallantry award, which is a testament to the repeated bravery that they showed in fighting off the people who were literally swarming over their tank." "Passchendaele was eventually taken by Canadian troops on 10th November, 1917." "Corporal HC Baker wrote that, "the village was so thickly strewn with shell-exploded bodies" ""that a fellow couldn't step without stepping on corruption"." "Just over a mile from the village," "Tyne Cot, the largest cemetery for Commonwealth forces in the world, holds 12,000 of the men who died." "When you add the names of those whose bodies were never found, the numbers are even more sobering." "140,000 men killed just to capture five miles of enemy territory." "Barely two inches of ground for each man lost." "A senior British officer who came to Passchendaele after the battle and saw the destruction burst into tears and asked, "My God, did we really send men to fight in this?"" "Well, they did." "And again and again for another year of war." "In the year following Passchendaele, the tide of war turned in favour of the Allies." "America finally committed to joining the conflict and by the middle of 1918 the influx of new soldiers was helping to tip the balance." "As the year came to a close, German soldiers started to surrender in massive numbers and in October Germany admitted defeat." "At 11am on the 11th of November, the guns were at last quiet." "Slowly, the people of France and Belgium came back to their shattered lands." "The airship filmed extraordinary scenes as communities tried to rebuild lives out of nothing." "Jacques Trolley de Prevaux flew low over the French city of Lens." "Here they still held their weekly market, next to houses so damaged all that remained were the gaping holes of what were once cellars." "'Therese de la Rouelle still lives in the same area that her parents returned to in 1918.'" "After the war, when your parents came back, what did they find?" "What was here?" "TRANSLATED:" "Everything was demolished." "There was nothing left." "It was a field of ruins." "My father had always dreamed of going back to his farm, and he was ruined." "But they wanted to have a nice family and what mattered to them most was the children's education." "What did they find?" "Was there anything left of what they'd owned?" "When they came back, my parents had absolutely nothing, but they did find one thing under the ruins of the house." "I'll show it to you." "It's what people used in those days for a bread knife, before the First World War, because my grandparents had a bake house, with a bread oven." "This was the only thing that was left from the ruins of the war?" "A bread knife." "Yes, a bread knife." "And she also had her clock." "My grandmother had taken it with her." "It was her treasured possession." "She'd taken it to Normandy when they were refugees." "And these are the only two things we have left that belonged to our grandparents before WWI." "In the months and years that followed the war, life began again in this ravaged corner of Europe." "But there remained the task of burying the dead." "Hundreds of British and Commonwealth cemeteries were built along the Western Front." "'There were also a handful of German cemeteries, like this one at Fricourt on the Somme, 'where 17,000 soldiers lie buried.'" "By the time the war ended, there were a million and a half dead Germans and the country faced a massive bill for reparations - six and a half billion pounds." "Already broken, Germany would now be humiliated and made to pay." "After his epic journey along the Western Front," "Jacques Trolley de Prevaux turned his airship back home to Paris, filming the French capital untouched by war." "Near here, the world's leaders had gathered to discuss how to deal with Germany in the fighting's aftermath." "At the grand Palace of Versailles, they drew up a peace treaty designed to punish Germany and to ensure that this really was the war to end all wars." "By the time the Treaty of Versailles was signed on June 7th, 1919, most of the men who had fought in the war and survived had gone back home to try to rebuild civilian lives they'd known before." "But the conflict had also created a restless generation, men who now looked to the future for adventure and challenges, men like the airship pilot Jacques Trolley de Prevaux." "De Prevaux's flights over the Western Front had been a unique experience, starting with its most northerly point and the floods over Nieuport, flying over landscapes studded with shell holes and scarred with lines of trenches." "And filming towns and villages that lay in ruins." "But just 20 years later, the great promises of Versailles were broken and de Prevaux's country threatened once again." "A new world war began and Paris was occupied by the Germans." "Jacques Trolley de Prevaux would fight the enemy in very different circumstances." "Flying the airship along the ruins of the Western Front had turned de Prevaux into a staunch patriot, determined to defend France in the future." "And that determination would lead him, ultimately, to tragedy." "20 years after his flight, when the Second World War began," "Jacques Trolley de Prevaux was living in Paris." "There he met and married a beautiful Polish fashion model, Lotka." "Three years into the fighting, in 1943, they had a daughter named Aude." "'Aude still lives in Paris, and I'm going to meet her to find out more about her father." "'Both her parents died when she was still a baby, but in the last few years, Aude's been piecing together 'their incredible life story.'" "By the time of WWII, your father is a captain in the French navy, but he decides he's not going to give up, not going to surrender." "And so he stays." " And he acts as an agent, a spy, along with your mother." " Yes." " A team." "What was their life like during that period?" "Em, my mother was always on the roads... ..with documents to deliver." "Or accompanying people to hide them or to bring them to a safe place." "And my father was pretending he was a shopkeeper, travelling with goods to show and to sell." " That was his cover." " Yeah." "His cover." " The Gestapo eventually closed in on your parents, they arrested them." "Mm-hm." "There was among them a traitor." "And they went to my mother's house and arrested her and she had just a few seconds to take me and give me very quickly to my nurse." "Saying, "Hide the baby!" So she was taken, too, and they were arrested and tortured and nobody...nobody told anything." "They kept a silence." " It was pretty brutal torture." " It was." " They used electric shocks, they immersed them in water." " Yes." " Among other things." " Yes." " But they never spoke." " They never spoke." "After their arrest, did they ever see each other again?" "They saw each other when they were killed, when they were shot, yes." " They took them to this airfield and they dug trenches?" " Yes." " Stood them in front of the trenches and machine-gunned them." " Yes." "And...yes." "That was the end." "Do you know...that your father took an airship right across the Western Front at the end of the Great War?" " No." " Yes." " Uh-huh?" "And he also brought with him a cameraman and they filmed it." " Ah?" " Yes." " Really?" "Yeah." " And there is footage, there is a film..." " Uh-huh?" " ..which was taken by your father." " Are you sure?" " I'm absolutely positive." " Well!" "And you can see your father in this film." " Would you like to see it?" " Oh, yes!" "A film?" " Yeah." "Yes." "He was smiling." "Was he?" " Yeah." " I never..." "In all the photos, he is always so severe." "I couldn't imagine him smiling." "And now I saw him smiling." "What does it mean to you, watching him like this, seeing him like this?" "It's very moving." "I couldn't expect seeing my father alive." "Ah." "It's a complete shock." "Ahh." "This is a happy moment?" "Oh, yes." "Happy, but painful, too." "Yes." "It's a great moment." " It's like as if he was alive." " Really?" " Ah, yes." "The story of men like Jacques Trolley de Prevaux epitomises a generation that faced the challenge of total war." "On the other side of Paris, beneath the Arc de Triomphe, is a monument commemorating those who died in the First World War." "The Tomb of the Unknown Soldier." "A single grave containing the body of one unidentified combatant." "Killed in a struggle that had claimed the lives of some 16 million people." "Those four years between 1914 and 1918 would change forever the way war was fought, but couldn't alter a fundamental truth of the battlefield - war is fought between individuals." "And to them belongs its courage, its terror and its sacrifice." "Subtitles by Subtext for Red Bee Media Ltd - 2010" "Email subtitling@bbc.co.uk"