The Terracotta Army: Ancient China's Lost Warriors Revealed

Over 2,000 years ago, the Chinese created one of the greatest marvels of the ancient world. Thousands of terracotta warriors, all life-size, fully armed and built for eternity. But they were lost and only rediscovered in 1974. Now the latest research allows us to tell their story. We found amazing archaeological objects. And the implications are enormous for archaeology. It's going to be truly revolutionary. Discovering who created them, how and why, uncovers an amazingly advanced civilization. The Chinese crossbow is two millennia ahead of its time. Whose ancient weapons excel in rigorous modern tests. You cannot make a better arrowhead than this. Cutting-edge science brings to light a lost world. We reveal the eternal secrets of the terracotta army. It's been called the eighth wonder of the world. A vast army of around 8,000 warriors. All life-sized, built to be immortal and made from terracotta or baked clay. Their scale is matched only by their beauty. The terracotta army is one of the ancient world's greatest engineering, manufacturing and artistic achievements. A stunning array, not just of infantry, but cavalry and chariots. But the terracotta army was just the start. A small part of a vast mausoleum covering an area almost the size of Manhattan Island. Hundreds of subterranean tombs. Filled with warriors, birds, animals, acrobats, officials and musicians. As well as mass graves of people and horses buried alive. All created 2,200 years ago in the 3rd century BC. They surround a mysterious tomb mound. But for over two millennia, they were lost and only recently discovered. The terracotta army site is incredibly important for world archaeology. You see just how majestic it could be, just how incredible it was. And you can look at it and say, wow, ancient China was amazing. The excavation of the terracotta army and mausoleum changed everything we know about ancient China. Yet at the same time, has left so many questions unanswered. Why was the terracotta army created? How did ancient Chinese craftsmen engineer such a colossal and complex project? Who created it? And what does the site tell us about them? We knew very little about the Qin Empire until the terracotta army was uncovered. Suddenly, you find this incredible evidence of what the soldiers wore, what their military technology was like. So we're seeing an entire culture revealed to us, whereas before we had almost nothing to go on but stories. Stories about an empire that was largely forgotten because most of its records were destroyed. The oldest surviving account about the Qin Empire was written nearly a century after the terracotta army was built by the father of Chinese history, Su Maqian. He tells of a brutal Qin state where scholars were buried alive. But neither Su Maqian nor any other ancient source made any mention of the terracotta army. Over two millennia ago, they were buried and forgotten. No one knew they ever existed. Until one day in 1974, during a drought in Shaanxi province, when Mr. Yang and other local farmers started digging a well. As he tells historian Jonathan Clements. As they were digging down, they found what they first thought to be the rim of a pot. They also found bronze, they find metal artefacts. So they start dragging cartfuls of broken terracotta out of this well. As they dug away the earth around it, they realised that they were looking at the body of a statue. They had the top of the armour and they saw an arm. If it's a grave, that is bad news. Of course, what he didn't know was that this was actually the most important archaeological finding in China of the last 100 years. And it tells us an incredible amount of the time of the first emperor. The farmers had made one of the world's greatest archaeological discoveries. Excavations soon found more terracotta shards. Bits of legs, headless bodies and even broken horses. All smashed after 22 centuries underground. They had been buried under a man-made roof in three large pits. A whole army with thousands of warriors and scores of chariots. Then an elaborate restoration process began. Slowly revealing a treasure trove of information. The warriors then placed back in the main pit. So far, more than 1,100 figures have been restored and displayed in pit one. But these are only a fraction of the 6,000 warriors that surveys have shown are buried here. With over a thousand more in pits two and three. We found amazing archaeological objects. So I think we cannot guess what buried beneath in the whole tomb complex. They are still making new discoveries, as museum director Chao explains. In 1974, when we discovered it, it shocked the world. It was unique in the world. We now have five excavation sites in the Qinzhi-Huangling area. We started excavating in 2009. We also have another excavation site in Baixi-Yongkeng. As well as the broken figures, the archaeologists found swords, lance blades and arrowheads in the pits. But are they ceremonial or war-grade? And just how did this ancient culture manage to overcome the design and technological challenges to create such a diverse site on such a vast scale? It's a mystery that a joint team from University College London and the Terracotta Army Museum are investigating. There are two types of visitors to the Terracotta Army. Some appreciate the beauty in the detail. You can choose any of these warriors and you will immediately admire the very personal facial expression, the individual hairstyle. Other people are more taken by the sheer scale of this site, its magnitude. How was it possible to orchestrate all the technological knowledge, all the resources and all the manpower needed and to do it so quickly? All within 37 years, the length of the reign of Qin Shi Huang, the terrifying first emperor of China. Modern historians agree with Sima Qian's historical records that he was crowned in 246 BC. And that's when work probably started on his mausoleum. This was miraculous because for over two centuries, the Qin state and its six powerful neighbours had been at war. Then the first emperor conquered them all, now ruling millions of people and an area that rivaled the size of the Roman Empire. He unified China with a universal legal system, one currency and intercity highways. What we now call China is only called China because of the first emperor. The problem that the Chinese have today is reconciling this idea that he was a cruel tyrant and that hundreds of thousands of people suffered and died under his regime. Sima Qian lists some of his crimes. Massacring prisoners of war, burning books and slaughtering his critics. But also that he did some good, that he unified China, that he took these disparate states with different languages and with different writing systems and he forced them all to be Chinese. To reflect these achievements, the emperor demanded the greatest mausoleum ever built. Recent surveys and mapping of the ongoing discoveries shows the site is far larger than originally thought. Starting with our carefully mapped data sets, you begin with some of the familiar parts of the site, for example, pit one, and then we can expand to some of the really interesting detail that has been excavated more recently. Since the first discovery of pit one, the site has expanded and grown more complex. The conservation area now covers over 50 square kilometres. Right at the heart of it, the first emperor demanded his own huge tomb. The grand historian said the imperial grave was under a mound, originally 115 metres tall. Buried deep underground was a huge chamber, surrounding the emperor's bronze coffin. We can only imagine the tomb's fabled interior as it will not be excavated until the contents can be safely preserved. Suma Qian's vivid description details his bronze coffin circled by a hundred mercury rivers and seas, all covered by the heavenly bodies and surrounded by the features of the earth. The tomb mound is at the centre of his vast mausoleum, built so his afterlife matched his luxurious life. Huge dams diverted water around the tomb and hundreds of graves were filled with horses, over 600 pits and tombs in all. So we're finding musicians and acrobats and weightlifters and we're finding scholars and scribes. This is not just a mausoleum, but a pleasure palace for his afterlife. His spirit could even travel in two half-sized chariots, each pulled by four bronze horses, embellished in gold and silver. The warriors were placed one and a half kilometres to the east of the imperial tomb mound, between the emperor's grave and the states he subjugated. The Qin belief system said the spirits of the emperor's many victims would seek revenge in the afterlife. So he was now protected by the immortal force of ever-loyal terracotta warriors, buried to combat any threats from the underworld. But how do you create something so vast, detailed and beautiful, the like of which has never been made before? A careful examination of the damaged figures reveals the first clues to how they were made. Each figure was hand-crafted from the local clay. And the broken figures show how the torso was created by coiling clay around in layers to build the upper body. Master craftsman Mr Han has studied the warriors with the museum curators and worked to replicate ancient production methods. So what's the weight of an average warrior? About 200 kilos. That's over 400 pounds, wow. Yeah, so that's very heavy. Arms, hands and heads were all cast. The original legs adapted from mould made for drainpipes. A process that produces a variety of limbs that can be combined with the torsos in different ways to create a mix of figures. Archers, heavy infantry, cavalrymen, generals, officials and charioteers and even their horses. Once the hollow mould is filled out with clay, it's joined and allowed to dry, ready for firing. Again working with the museum curators, Mr Han has built a replica of an ancient chin kiln. So it's based on the real chin archaeology? Yeah, that's based on the chin, real chin archaeology. The figures are sealed up and then fired to make them hard. Today, reassembling the broken figures is the first part of their restoration. It's a process that allows minute inspection and gradually reveals a multitude of looks and appearances amongst the figures. They seem dark and light-skinned, with a variety of facial hair. They sport a variety of eye shapes and have a dazzling array of hairstyles. There are clearly differences and variations, but is each one truly unique? To find the answer, the scientists need exact 3D models for precise measurement. But laser scanning is time-consuming and expensive. So Dr Janice Lee is using a stills camera to start an innovative and revolutionary process that will turn her 2D pictures into 3D models, allowing exact comparisons. This is a very new technique. Now the challenge for archaeologists for capturing 3D data has always been that it's expensive, that it involves complicated equipment. Now you can collect the same data using ordinary photos, and the implications of that are enormous for archaeology. And it's going to be truly revolutionary. At University College London, Dr Andrew Bevan is compositing Janice's photographs to create a 3D model. The reason we're really interested in creating these 3D models is purely for analytical purposes. That is, we want to compare the shapes of different terracotta warrior heads and to do so we need a version which is not the real terracotta warrior, but a 3D model, something that we can analyse statistically. You need a lot of overlap between the photographs because what the software tries to do is to go through each photograph and define a set of features that it can recognise. It might be, for example, the tip of an ear. The computer compares the images and starts to match features. Once it's done that, it will create what's known as a sparse point cloud. It's the building block for these more complicated models. The computer then maps these points in three-dimensional space and joins them up to create the head. Slowly, slowly, you'll get the outline of a head appearing. We've done this particular warrior in all of his glory. These exact models allow precise statistical comparison of anything from hands to heads, arms to armour, or figure to figure. Now that we've got these 3D models, we can start comparing them. I mean, effectively, the sky's the limit. In humans, no two ears are the same. They are as unique as fingerprints. In this particular case, I'm going to have off the ear of the warrior so it could be compared to some others. The results are startling and clear. Here, I've got some of the ears that we modelled, and you can see just visually that there's a great deal of difference between those ears. For example, in the degree to which they've got a pronounced ear lobe, the depth of the well in the middle of the ear, you can see, for example, that this ear, this ear, and perhaps that ear, they're a little bit more similar with one another. But that ear and that ear, very different. What we've discovered so far through these 3D models is that no two ears are demonstrably the same. These warriors seem to be very individual in the same way as a typical human population. This is strong evidence that the emperor wanted to be defended by a real army of individuals in his afterlife. But it's the skill of the craftsmen that gave these moulded heads their very personal features. But Han's work really reflected the processes of making terracotta warriors 2,000 years ago. Yeah, so it normally takes three days for Han to carve. Mr Han's ears. Yeah, it's really a big ear lobe there, yeah. Years of careful restoration, preservation and analysis have gradually revealed the tiny clues that the terracotta army originally looked very different to what we see today. Numerous torsos, hands and heads contain teasing flakes of shaded pigments, revealing the warriors were originally highly decorated. And suggest a colourful, even flamboyant array when first created. We can now see how the warriors may have looked 2,200 years ago. A dazzling array of painted figures and ornate chariots, all fully armed. Today, the terracotta armies still look intimidating. But when they were first created, they were terrifying. But were they carrying symbolic armaments or sharpened, war-grade weapons? After the wooden parts rotted away, all that was left on the floor were the metal components of the weapons, once held by the warriors. How were these weapons made? And how were they used? To find the answers, Dr Janice Lee is adapting an innovative dental technique that uses silicon moulds to get casts of teeth so she can examine the weapons microscopically. By putting the silicon impression under a scanning electron microscope, Janice can examine the blades without damaging them. At 80 times magnification, the screen is filled by just a 1.5mm section of the blade. This shows these blades were originally sharp and, amazingly, they still are today. These parallel fine marks show that's really massive effort for sharpening these functional lethal weapons. So consistent, so you cannot do this by hand. Every one of the 40,000 arrowheads were sharpened by somebody on a wheel. Definitely, you can see it's very parallel. It reveals that the Qin used state-of-the-art machines to sharpen metal on a mass scale, for the first time in history. Only one machine could make these fine, even lines. A rotary lathe that uses a spinning stone to sharpen blades. All the swords, all the lances, all the halberds and every one of the 40,000 arrowheads have been sharpened in the same way. It's the earliest evidence we have of the use of a rotary polishing device on such an industrial scale. There's no sign whatsoever of them having been used. There's no notches or scratches. So these were not taken out of the real army to then place them with the terracotta army, but these are freshly made weapons delivered directly to the terracotta army. No, really well done. This is fantastic. I think we are on to something exciting. The team's work is revolutionising our understanding of how and why the Qin produced their weapons. I think it's obvious these are not representations for religious purposes. These are real lethal weapons made to kill. The terracotta army was arrayed in the Qin battle formation. The heavy infantry at the core were armed with the deadly zhe, or halberd. Now forgotten, this long shafted weapon was highly flexible in battle and was the Qin army's best defence against their greatest foe. A major threat to all Chinese armies of all states was cavalry, both horsemen and charioteers. And the principal defence against them was the halberd. Now, obviously I had to stop the horse there or he would have impaled himself on the spear. And that's really the first function of the halberd. And you'll see it's got this cross piece, this transverse bar. So if I had gone hurtling into a line of halberds, this would have skewered the poor horse here, but it would have stopped. So the halberdier himself doesn't get trampled. He can also use the spike to take out the horse's leg. But what if the animal gets past the point of the halberds and I'm coming in with a lance, he could use his halberd to lift the point so that it's done that. And that's pushed it onto my throat and he has pushed me and where he can obviously be quickly dispatched. As well as the lance and halberd, the Qin deployed a range of metal weapons, including spears and long swords. But the ancient Chinese led the world in one particular weapons technology, archery. Literary sources show the Chinese invented the crossbow centuries before the Qin Empire. And it had evolved to be the most effective weapon of the age. The Chinese battlefield was full of arrow storms, storm after storm of arrows. But that takes skill and training. How could you do that with an army full of peasant conscripts that were there for a few months? Well, the answer was in the Chinese crossbow. Just a simple stock of wood easily mounts any bow. So the bow is already made. It fits onto there. And just with putting a cross piece in there, you could lash that into position. No complete originals survive, but this is a working replica. Its importance is shown by the ranks of terracotta archers, ready for battle. But all that remains of the Qin crossbows are clusters of strange bronze objects found in the pits. These bits of bronze might not look like anything recognisable at first. Put them together, however, and you've got an extraordinary mechanism. This is a bronze crossbow trigger, one of the most sophisticated three-dimensional engineering mechanisms of ancient times. Chinese historians recorded that each part had to be a precise match, so they can all fit together. The Annals of Lu Bui, who date to around the time of the first emperor, claimed that if there's any misalignment in the parts of a trigger, it will not function. That's how accurate they had to be when making these parts and then assembling them together into a functional crossbow trigger. Military historian Mike Loades demonstrates its ingenuity with this replica. The real genius was the trigger. The bronze, the cast bronze trigger produced to a standardised form in their hundreds of thousands. So it's got its very simple interchangeable component parts. It comes apart very easily and it goes together very easily. And this whole assembly just drops into a pre-carved slot in the bow and you have got a bow ready to shoot. This revolutionary trigger locks solidly and can securely hold and smoothly release the power of the bow. So this seemingly simple mechanism is two millennia ahead of its time. It is an ingenious bit of mass-produced, standardised military equipment. But any crossbow is only as deadly as its arrows. Over 40,000 chin arrowheads have been excavated. This is just one bundle of a hundred. A quiverful. Discovered here in the middle of pit one. Professor Martín Ontorres is pioneering the use in archaeology of an X-ray fluorescent spectrometer from mining to make some startling discoveries. This is today the simplest, fastest, even cheapest way we have of determining the chemical composition of something. It's only recently that we are beginning to use it in archaeology, bringing about a revolution in the way we can characterise materials. It shows the terracotta army's weapons are nearly all made from bronze, a man-made alloy comprising a mixture of copper and tin. The expectation is that all the arrows will be made from one blend of bronze. This is telling us the recipe that the weapon makers had for each of the parts of their weapons. There's the head proper and then what we call the tang, which would be inserted in the longer bamboo shaft. The tang contains 3% tin, 1% lead and the rest is copper. So it tells us that this is a bronze with relatively low amounts of lead and tin. We can now turn it over. We can immediately see a relatively high tin content that's around 20%. This is an alloy that we know would be extremely hard. More tin makes for a harder, sharper arrowhead. But less tin makes the tang more flexible and less likely to snap on impact. When you only have bronze, you cannot make a better arrowhead than this. This is as good as a bronze weapon is going to get. But how did they create an advanced arrowhead and tang combining two alloys? Master forger Andy Lacey is experimenting, trying to reproduce the casting techniques developed in China over 2,000 years ago. You have your tang precast, already exists. You just insert it into the mould. You can see that it sits within the space that's the arrowhead. And then you put the top part on and clamp it together. Then you see the tang just sticks out there and that's the funnel that would take the metal in. Well, it does look like an arrowhead. Oh, that's good, that's good. There we are. Okay, that's not bad. Not at all. It's got these two components beautifully together. Yeah, that's the important thing. So that's welded on very tightly. Joining the two alloys reveals the chin's enormous sophistication and innovative production skills. But only a rigorous test can show if Andy's arrowheads perform in action. Ancient Chinese sources give clues to how the bows were loaded, showing the strength and power needed. We have some evidence that the chin laid on their backs to span their bows. That would suggest pretty powerful bows of about 200 pounds, which is more powerful than a hand bow is going to be. Mike's demonstration bow only has a 23 kilogram draw weight, a quarter of an authentic chin crossbow. We're now shooting with more than four times the power. This modern bow matches the power of the chin bow and pushes the replica arrows to their limits. It's devastating against ballistic gel, but how will it perform against Chinese armor? This is the level of armor that an arrow has to defeat. It's lamellar armor. That means you've got scales which overlap each other. And then behind that is soft textile armor. And you can see on the terracotta warriors, they're wearing quite bulky clothing and armor is a composite defense of hard exterior with soft padding and they've probably got felt coats under that. Deep inside here is a piece of pork to represent the human being inside. So that's the challenge an arrowhead has, delivering that crucial thump to the target. Well, it's stuck in. It's done something. Look at that. It's gone right through the armor. In fact, it's gone right through, right through the pork. And here it is out the other side. Look at that. A demonstration further proven by this skull found with the terracotta army. An arrowhead buried deep into the bone. The Qin and all their neighbors had been at war for over two centuries. In 223 BC, the Qin faced the vast Chu army on the banks of the Yangtze River. The Qin led them into a trap and then attacked with their devastating archers. You can learn to use this in less than two minutes and it enabled a peasant army to be converted into state-of-the-art troops. The Qin conquered the Chu and their other neighbors until in 221 BC, the first emperor ruled them all. The grand historian, Suma Qian, describes his increasingly tyrannical rule, banning all opposition and burning records. All of the books in his kingdom were destroyed. Possibly thousands of Chinese documents that will never get back. A terrible cataclysm for Chinese history and for Chinese historians. Imperial megalomania took over as 700,000 workers were forced to expand his tomb complex. On the far western edge of the site, chilling evidence has revealed the dark secret behind the production of this mausoleum. Dr. Janice Lee is heading into the orchards, where mass graves were filled with the bodies of workers, worn down by the relentless toil. All controlling Qin bureaucracy gave each body a pottery death certificate. Each is a moving testimony to their enforced labor. The story of worker, Bu Gongju, forced to work as he couldn't pay the crippling debt he owed the government, is typical of the unskilled laborers working for the first emperor. All this enforced labor helped the Qin to create the Chinese empire. Protected with over 8,000 kilometers of the First Great Wall. Connected with intercity highways and irrigated with canals and locks. While more skilled artisans made the 8,000 individual and fully armed warriors. But how did the Qin create it all so quickly on such a vast scale and with such attention to detail? All the strands of the team's work can now reveal how the workforce was organized and controlled. We have hundreds, thousands of weapons here all of which look very standardized, mass produced. But we want to find out how that was achieved. How is it that they could produce so many weapons in such a relatively short period? The answer lies in the weapons themselves. To help analyze them, Janice has meticulously plotted all the armaments found in pit one. This is the map of all these bronze weapons discovered in the east part of pit one. So we show in different colors different kinds of weapons. So like the red one shows the bronze triggers crossbow triggers discovered in the pit and the black dots presents the arrow bundles. She then compares this with the detailed analysis of the triggers and arrowheads. Finding that the triggers can be divided into different groupings where each trigger in that batch is identical in size. Those colors are all of the different trigger groups that we've been able to identify. Janice's plots of the find locations in pit one identified several different batches of triggers. Careful analysis shows groups sharing identical size and design such as these in the northeast corner of the pit. Proving they were made by the same cell of workers. Next to them is a different batch of triggers identical to each other. Showing they were made by another cell of workers. This is a series of cells working individually to create these metal weapons. All of this requires a very versatile workforce that can produce a sword today, a crossbow tomorrow, a halberd the day after. Depending on what's needed as the work moves forward. Only cells of skilled workers had the flexibility to be this productive and versatile. Janice has also found startling evidence as to how they were organized by decoding the markings on the blades. These reveal the names of the workers and a terrifying structure of strict control. This is one of the supervisory trees that Janice has created based on the descriptions. So this is the one based on the inscriptions from the halberds. We can see individual workers working on different years of the reign of Qin. Above them, the craftsmen, foremen that would be working with them, the officials, and then on top of all, Liu Buwei who was then the prime minister or the chancellor of Qin. The craftsmen at the bottom had to sign their names so any substandard work could easily be traced. Sometimes people refer to this supervisory system for quality control as a carrot and stick system. We don't have massive evidence about the carrots but we know about the sticks. Basically, we know that if something was wrong with a particular weapon that didn't fit the standard then one could identify worker Jin in particular and make him accountable for his error. Everything had to be perfect for an immortal army. Created to defend the first emperor in his afterlife and perfection was achieved through terror. The state of Qin didn't just define things like theft and murder as crimes. Incompetence was also a crime. So not meeting a particular standard of workmanship would also have been met with savage punishment. Maimings, you have tortures, you have executions. Just part of the system that Qin had created to rule every aspect of life in the empire. It was called legalism and it was terrifying. The grand historian Su Maqian describes a society ruled by fear, divided into groups of five and ten. Each person forced to be a spy and liable for the others. Every unit of five or ten houses was obliged to report on each other. If anyone committed a crime within your cell and you didn't report it, the entire cell would be punished. It's very likely that just as the army and society was divided up in this cellular way that the artisans, the blacksmiths and the potters of the Qin world also worked on very similar lines. It creates a vicious, brutal society of people informing on each other and everyone was terrified. Over 450 inscriptions on the figures themselves provide further evidence of a workforce organised into cells. These markings name over 90 foremen and suggest that each led 10 skilled craftsmen. They came from the palace factories or local workshops. Studying the tiny details has revealed that the Qin deployed cells of skilled workers, capable of mass-producing both weapons and individualised figures. Controlled by a legalist system that made them too frightened to fail. I think this production model holds the key to understand how it was possible to produce something so colossal, so big but also so sophisticated in a time window of maximum 40 years, quite possibly less. In 210 BC, 11 years after he conquered all his neighbours, the first emperor died, possibly killed by the mercury pills that he's said to have consumed to bring immortality. Suma Qian records he was buried in a bronze coffin surrounded by rivers of mercury, laid out in a map of the empire. His tomb mound has never been excavated, but the terracotta army opened the door to a lost world. This unprecedented site stands as testimony to the ingenuity and ruthlessness of the ancient and largely unknown Qin culture. Its pioneering system of flexible manufacturing, combined with rule by terror, allowed the Qin to create the eternal wonder of the terracotta army. It explains how one little nation created a vast state that has evolved, expanded, and continues to thrive over 2,000 years later. China.