So how do you lead and control a city or a state where most people don't know each other, and you can interact personally with only a very small percentage of the inhabitants? It's been a problem for politicians for more than 5,000 years, ever since the groups we live in exceeded the size of a tribe or village. The world's first crowded cities and states grew up in fertile river valleys: the Euphrates, the Tigris and the Indus. This chapter's object is associated with the most famous river of them all, the Nile. It comes from the Egypt of the pharaohs, where the answer to the question of how to exert leadership and state control over a large population was quite simple: force.

If you want to investigate the Egypt of the pharaohs, the British Museum gives you a spectacular range of choices monumental sculptures, painted mummy cases, and much more but I've chosen an object that came quite literally from the mud of the Nile. It's made from a tusk of a hippo, and it belonged to one of Egypt's first pharaohs King Den. Perversely for an object that's going to let us explore power on a massive scale, it is tiny.

It is about 5 centimetres (2 inches) square, it's very thin, and it looks and feels a bit like a modern-day business card. In fact, it's a label that was once attached to a pair of shoes. We know this because on one side is a picture of those shoes. This little ivory plaque is a name tag for an Egyptian pharaoh, made to accompany him as he set off to the afterlife, a label which would identify him to those he met. Through it, we're immediately close to these first kings of Egypt rulers, around 3000 BC, of a new kind of civilization that would produce some of the greatest monumental art and architecture ever made.

The nearest modern equivalent I can think of to this label is the ID card that people working in an office now have to wear round their necks to get past the security check though it's not immediately clear who was meant to read these Egyptian labels, whether they're aimed at the gods of the afterlife or perhaps ghostly servants who might not know their way around. The images themselves are made by scratching into the ivory and then rubbing a black resin into the incisions, making a wonderful contrast between the black of the design and the cream of the ivory.

Before the first pharaohs, Egypt was a divided country, split between the eastwest coastal strip of the Nile Delta, facing the Mediterranean, and the northsouth string of settlements along the river itself. With the Nile flooding every year, harvests were plentiful, so there was enough food for a rapidly growing population and, frequently, surplus to trade with. But there was absolutely no extra fertile land beyond the flooding area, and as a result the ever more numerous people fought bitterly over the limited amount of land. Conflict followed conflict, with the people from the Delta eventually being conquered by the people from the south just before 3000 BC. This united Egypt was one of the earliest societies that we can think of as a state in the modern sense, and, as one of its earliest leaders, King Den had to address all the problems of control and coordination that a modern state has to confront today.

Engraved on the back of the label is a pair of sandals You might not expect to discover how he did this from the label on his shoes, but Den's sandals were no ordinary shoes. They were high-status items, and the Keeper of the Sandals was one of the high court officials. It's not so surprising, then, that on the back of the label we have a clear statement of how this pharaoh exercised power; nor, perhaps, that the model which evolved in Den's Egypt 5,000 years ago resonates uncannily around the world to this day.

On the other side of the label is an image of the owner of the sandals, dressed in a royal headdress with a mace in one hand and a whip in the other. King Den stands in combat, authoritatively smiting an enemy who cowers at his feet. Of course, the first thing we look for is his sandals but, disappointingly, he's barefoot.

This little label is the first image of a ruler in this history of humanity. It's striking, perhaps a bit disheartening, that, right at the beginning, the ruler wants to be shown as commander-in-chief, conquering his foe. This is how, from earliest times, power has been projected through images, and there's something disturbingly familiar about it. In its simplified forms and its calculated manipulation of scale it is eerily reminiscent of a contemporary political cartoon.

The label-maker's job was, however, deadly serious: to keep his leader looking invincible and semi-divine, and to show that Den was the only man who could guarantee what Egyptians, like everybody else, wanted from their rulers law and order. Within the pharaoh's realm, everybody was expected to conform and to take on a clear Egyptian identity. The message of our sandal label is that the price of opposition was high and painful.

This message is carried not only in the image but also in the writing. There are some early hieroglyphs scratched into the ivory which give us the name of King Den and, between him and the enemy, the chilling words 'they shall not exist'. This 'other' is going to be obliterated. All the tricks of savage political propaganda are already here the ruler calm and victorious, set against the alien, defeated, misshapen enemy. Who he is we don't know, but on the right of the label is an inscription which reads: 'The first occasion of smiting the east'. As the sandy ground beneath the figures rises to the right-hand side, it has been suggested that the enemy comes from Sinai in the east.

The area that King Den's unified Egyptian state was able to coerce and control is staggering. At its height, it included virtually all the Nile Valley from the Delta to what is modern Sudan, as well as a huge area to the east up to the borders of Sinai. I asked the archaeologist Toby Wilkinson what building a state on this scale required: This is an early period in Egypt's history, when the nation is still being consolidated, not so much territorially as ideologically and psychologically. The king and his advisers are looking for ways to reinforce Egypt's sense of its own nationhood, and support for their regime. I think they realized, as world leaders have realized throughout history, that nothing binds a nation and a people together quite so effectively as a foreign war against a common enemy, whether that enemy is real or manufactured. And so warfare plays really a key role in the consolidation of the Egyptians' sense of their own nationhood.

It's a discouragingly familiar strategy. You win hearts and minds at home by focusing on the threats from abroad, but the weapons that you need to crush the enemy also come in handy when you're dealing with domestic opponents. The political rhetoric of foreign aggression is backed up by very brisk policing at home.

So the apparatus of the modern state had already been forged at the time of King Den, with enduring consequences which were artistic as well as political. Only power of this order could organize the enormous building projects that these early pharaohs embarked on. Den's elaborate tomb, with granite shipped from hundreds of miles away, and the later, even grander pyramids were possible only because of the extraordinary control which Egyptian pharaohs could exercise over the minds and the bodies of their subjects. Den's sandal label is a miniature masterclass in the enduring politics of power.

12.

Standard of Ur.

Wooden box inlaid with mosaic, found at the royal cemetery of Ur, southern Iraq.

26002400 BC.

At the centre of pretty well all great cities, in the middle of the abundance and the wealth, the power and the busy-ness, you'll usually find a monument to death on a massive scale. It is the same in Paris, Washington, Berlin and London. In Whitehall, for example, just a few yards from Downing Street, the Treasury and the Ministry of Defence, the Cenotaph marks the death of millions in the great wars of the last century. Why is death at the heart of our cities? Perhaps one explanation is that in order to retain the wealth and power that our cities represent, we have to be willing to defend them from those who covet them. This object, from one of the oldest and richest cities of them all, seems to say quite clearly that the power of cities to get rich is indissolubly linked to the power to wage and win wars.

Peace: the king and companions feast while people bring tribute of fish, animals and other produce Cities started around 5,000 years ago, when some of the world's great river valleys witnessed rapid changes in human development. In just a few centuries fertile land, farmed successfully, became densely populated. On the Nile this hugely increased population led, as we have seen, to the creation of a unified Egyptian state. In Mesopotamia (modern Iraq), in the land between the rivers Tigris and Euphrates, the agricultural surplus, and the population that it could support, led to settlements of 30,000 to 40,000 people, a size never seen before, and to the first cities. Coordinating groups of people on this scale obviously required new systems of power and control, and the systems devised in Mesopotamia around 3000 BC have proved astonishingly resilient. They have pretty well set the urban model to this day. It's no exaggeration to say that modern cities everywhere have Mesopotamia in their DNA.

Of all these earliest Mesopotamian cities, the most famous was the Sumerian city of Ur. So it's not surprising that it was at Ur that the great archaeologist Leonard Woolley chose to carry out his excavations in the 1920s. At Ur, Woolley found royal tombs which themselves could have been the stuff of fiction. There was a queen and the female attendants who died with her, dressed in gold ornaments; accompanying them were sumptuous headdresses; a lyre of gold and lapis lazuli; the world's earliest known board-game; and a mysterious object, which Woolley initially described as a plaque: In the farther chamber was a most remarkable thing, a plaque, originally of wood, 23 inches long and 7 inches wide, covered on both sides with a mosaic in shell, red stone, and lapis; the wood had decayed, so that we have as yet little idea of what the scene is, but there are rows of human and animal figures, and when the plaque is cleaned and restored it should prove one of the best objects found in the cemetery.

This was one of Woolley's most intriguing finds. The 'plaque' was clearly a work of high art, but its greatest importance is not aesthetic: it lies in what it tells us about the exercise of power in these early Mesopotamian cities.

Woolley's find is about the size of a small briefcase, but it tapers at the top so that it looks almost like a giant bar of Toblerone and it's decorated all over with small mosaic scenes. Woolley called it the Standard of Ur, because he thought it might have been a battle standard that you carried high on a pole in a procession or into battle. It has kept that name, but it's hard to see how it could have been a standard of that sort, because it's obvious that the scenes are meant to be looked at from very close up. Some scholars have thought it might be a musical instrument or perhaps merely a box to keep precious things in, but we just don't know. I asked Dr Lamia al-Gailani, a leading Iraqi archaeologist who now works in London, what she thinks: Unfortunately, we don't know what they used it for, but for me, it represents the whole of the Sumerians. It's about war, it's about peace, it's colourful, it shows how far the Sumerians travelled the lapis lazuli came from Afghanistan, the red marble came from India, and all the shells came from the Gulf.

This is significant. So far, each of the objects we've looked at has been made in a single material stone or wood, bone or pottery all of them substances that would have been found close to where its maker was living. Now, for the first time, we have an object that is made of several different, quite exotic materials traded over long distances. Only the bitumen which held together the different pieces could have been found locally; it's a trace of what is now Mesopotamia's greatest source of wealth oil.

What kind of society was it which was able to gather these materials in this way? First, it needed to have agricultural surplus. It then also needed a structure of power and control that allowed its leaders to mobilize that surplus and exchange it for exotic materials along extended trade routes. That surplus would also have fed and supported people freed from the constraints of agricultural work priests, soldiers, administrators and, critically, craftsmen able to specialize in making complex luxury objects like the Standard. These are the very people that you can see on the Standard itself.

The scenes are arranged like three comic strips on top of each other. One side shows what must be any ruler's dream of how a tax system should operate. In the lower two registers, people calmly line up to offer their tribute of produce and fish, sheep, goats and oxen, and on the top register, the king and the elite, probably priests, feast on the proceeds while somebody plays the lyre. You could not have a clearer demonstration of how the structures of power work in Ur: the land workers shoulder their burdens and deliver offerings, while the elite drink with the king. To emphasize the king's pre-eminence just as in the image of King Den the artist has made him much bigger than anybody else, in fact so big that his head breaks through the border of the picture. In the Standard of Ur we are looking at a new model of how a society is organized. I asked a former Director of the London School of Economics, Professor Anthony Giddens, to describe this shift in social organization: From having a surplus, you get the emergence of classes, because some people can live off the labour of others, which they couldn't do in traditional small agricultural communities where everybody worked. Then you get the emergence of a priestly warrior class, of organized warfare, of tribute and something like a state which is really the creation of a new form of power. All those things hang together.

You can't have a division between rich and poor when everyone produces the same goods, so it's only when you get a surplus product which some people can live off and others have to produce, that you get a class system; and that soon emerges into a system of power and domination. You see the emergence of individuals who claim a divine right, and that integrates with the emergence of a cosmology. You have the origin of civilization there but it's bound up with blood, with dynamics, and with personal aggrandizement.

While one side of the Standard shows the ruler running a flourishing economy, the other side shows him with the army he needed to protect it. That brings me back to the thought that I began with: that it seems to be a continuous historical truth that once you get rich you then have to fight to stay rich. The king of the civil society that we see on one side has also to be the commander-in-chief we see on the other. The two faces of the Standard of Ur are in fact a superb early illustration of the militaryeconomic nexus, of the ugly violence that frequently underlies prosperity.

War: the king reviews captured prisoners while chariots trample the enemy Let's look at the war scenes in more detail. Once again, the king's head breaches the frame of the picture; he alone is shown wearing a full-length robe and he holds a large spear, while his men lead prisoners off either to their doom or to slavery. Victims and victors look surprisingly alike, because this is almost certainly a battle between close neighbours in Mesopotamia neighbouring cities fought continually with each other for dominance. The losers are shown stripped naked to emphasize the humiliation of their defeat, and there is something heart-rending in their abject demeanour. In the bottom row are some of the oldest-known representations of chariots of war indeed, of wheeled vehicles of any sort and one of the first examples of what was to become a classic graphic device: the artist shows the asses pulling the chariots moving from a walk to a trot to a full gallop, gathering speed as they go. It's a technique that no artist would better until the arrival of film.

Woolley's discoveries at Ur in the 1920s coincided with the early years of the modern state of Iraq, created after the collapse of the Ottoman Empire at the end of the First World War. One of the key institutions of that new state was the Iraq Museum in Baghdad, which received the lion's share of the Ur excavations. From the first moment of their discovery, there was a strong connection between the antiquities of Ur and Iraqi national identity. So the looting of antiquities from the Baghdad Museum during the recent war in Iraq was felt very profoundly by all parts of the population. Here's Lamia al-Gailani again: For the Iraqis, we think of it as part of the oldest civilization which is in our country and we are descendants of it. We identify with quite a lot of the objects from the Sumerian period that have survived until now ... so ancient history is really the unifying piece of Iraq today.

So Mesopotamia's past is a key part of Iraq's future. Archaeology and politics, like cities and warfare, seem set to remain closely connected.

The seal mould (top) and an impression from it

13.

Indus Seal.

Stone stamp, from Harappa, the Indus Valley (Punjab) Pakistan.

25002000 BC.

In the last two objects we have seen the rise of the city and the state. But cities and states can also fall. I want to take you now not just to a city that was lost, but to an entire civilization that collapsed and then vanished from human memory for more than 3,500 years, largely due to climate change. Its rediscovery in Pakistan and north-west India was one of the great archaeological stories of the twentieth century; in the twenty-first we are still piecing the evidence together. This lost world was the civilization of the Indus Valley, and the story of its rediscovery begins with a small carved stone, used as a seal to stamp wet clay.

We have been exploring how the first cities and states grew up along the great rivers of the world, and how these new concentrations of people and of wealth were controlled. Around 5,000 years ago the Indus River flowed, as it still does today, down from the Tibetan Plateau into the Arabian Sea. The Indus civilization, which at its height encompassed nearly 200,000 square miles, grew up in the rich, fertile floodplains.

Excavations there have revealed plans of entire cities, as well as vigorous patterns of extensive international trade. Stone seals from the Indus Valley have been found as far afield as the Middle East and central Asia, but the seals in this chapter were found in the Indus Valley itself.

In the British Museum there is a small collection of stone seals, made to press into wax or clay in order to claim ownership, to sign a document or to mark a package. They were made between 2500 and 2000 BC. They are all approximately square, about the size of a modern postage stamp, and they're made of soapstone, so they were easy to carve. And they have been beautifully carved, with wonderfully incised images of animals. There's an elephant, an ox, a kind of cross between a cow and a unicorn and, my favourite, a very skippy rhinoceros. In historical terms, the most important of them is, without question, the seal that shows a cow that looks a bit like a unicorn; it was this seal that stimulated the discovery of the entire Indus civilization.

The seal itself was discovered in the 1850s, near the town of Harappa, in what was then British India, about 150 miles south of Lahore in modern Pakistan. Over the next fifty years three more seals like it arrived in the British Museum, but no one had any idea what they were, or when and where they'd been made. But in 1906 they caught the attention of the Director-General of the Archaeological Survey of India, John Marshall. He ordered the excavation of the ruins at Harappa, where the first seal had been found. What was discovered there led to the rewriting of world history.

Marshall's team found at Harappa the remains of an enormous city and went on to find many others nearby, all dating to between 3000 and 2000 BC. This took Indian civilization much further back in time than anyone had previously thought. It became clear that this was a land of sophisticated urban centres, trade and industry, and even writing. It must have ranked as a contemporary and an equal with ancient Egypt or Mesopotamia and it had been totally forgotten.

The largest of the Indus Valley cities, such as Harappa and Mohenjodaro, had populations of 30,000 to 40,000 people. They were built on rigorous grid layouts, with carefully articulated housing plans and advanced sanitation systems that even incorporated home plumbing; they're a modern townplanner's dream. The architect Richard Rogers admires them greatly: When you are faced with a piece of ground where there are few limiting constraints, there are not many buildings and it's a sort of white piece of paper, the first thing you do is start putting a grid on it, because you want to own it and a grid is a way of owning it, a way of getting order. Architecture is really giving order, harmony, beauty, rhythm to space. You can see that in Harappa; that's exactly what they're doing. There's also an aesthetic element with it, which you can see from their sculpture they have an aesthetic consciousness, and they also have a consciousness of order, and a consciousness of economy, and those things link us straight over the 5,000 years to the things that we are doing today.

As we saw in Egypt and Mesopotamia, the leap from village to city usually required one dominant ruler, able to coerce and deploy resources. But just who ran these highly ordered Indus Valley cities remains unclear. There is no evidence of kings or pharaohs or indeed of any leader at all. This is largely because, both literally and metaphorically, we don't know where the bodies are buried. There are none of the rich burials which in Egypt or Mesopotamia tell us so much about the powerful and about the society they controlled. We have to conclude that the Indus Valley people probably cremated their dead, and, while there may be many benefits in cremation, for archaeologists it is, if I may use the phrase, a dead loss.

What's left of these great Indus cities gives us no indication of a society engaged with, or threatened by, war. Not many weapons have been found, and the cities show no signs of being fortified. There are great communal buildings, but nothing that looks like a royal palace, and there seems to be little difference between the homes of the rich and the poor. It seems to be a quite different model of how to create an urban civilization, without celebration of violence or extreme concentration of individual power. Is it possible that these societies were based not on coercion but on consensus?

We could find out more about the Indus civilization if only we could read the writing on our seal, and others like it. Above the animal images on the seals is a series of symbols: one looks like an oval shield; others look like matchstick human figures; there are some single lines; and there's a standing spear shape. But whether they are numbers, logos, symbols or even a language we simply don't know. Since the early 1900s people have been trying to decipher them, nowadays of course using computers, but we just do not have enough material no longer inscriptions, no bilingual texts to make confident progress.

The seals are often pierced, so they may have been worn by their owners, and they were probably used to stamp goods for trading they've been found in Iraq, Iran, Afghanistan and central Asia. Between 3000 and 2000 BC the Indus civilization was a vast network of complex, organized cities with flourishing trade links to the world beyond, all apparently thriving. And then, around 1900 BC, it came to an end. The cities turned to mounds of earth, and even the memory of this, one of the great early urban cultures of the world, vanished. We can only hazard guesses as to why. The need for timber to fire the brick kilns of the huge building industry may have led to extensive deforestation and an environmental catastrophe. More importantly, climate change seems to have caused tributaries of the Indus to alter their course or to dry up completely.

When the ancient Indus civilization was initially unearthed, the entire subcontinent was under British rule, but its territory now straddles Pakistan and India. Professor Nayanjot Lahiri from Delhi University, a specialist on the Indus civilization, sums up its importance for both countries today: In 1924, when the civilization was discovered, India was colonized. So to begin with there was a great sense of national pride and a sense that we were equal to if not better than our colonizers and, considering this, that the British should actually leave India. This is the exact sentiment that was expressed in the Larkana Gazette Larkana is the district where Mohenjodaro is located.

After independence the newly created state of India was left with just one Indus site in Gujarat and a couple of other sites towards the north, so there was an urgency to discover more Indus sites in India. This has been among the big achievements of Indian archaeology post-independence that hundreds of Indus sites today are known, not only in Gujarat but also in Rajasthan, in Punjab, in Haryana and even in Uttar Pradesh.

The great cities of Harappa and Mohenjodaro, which were first excavated, are in Pakistan, and subsequently one of the most important pieces of work on the Indus civilization was done by a Pakistan archaeologist Rafique Mughal [presently a professor at Boston University], who discovered nearly 200 sites in Pakistan and Cholistan. But my own sense is that on the whole the state of Pakistan has been much more interested, not exclusively but significantly, in its Islamic heritage, so I think there is a greater interest in India as compared to Pakistan.

There is not a competition but a certain kind of poignant sentiment that I have when I think of India, Pakistan and the Indus civilization, for no other reason than that the great remains the artefacts, the pottery, the beads, etc., that were found at these sites are divided between the two states. Some of the most important objects were actually divided right down the middle like the famous girdle from Mohenjodaro. It's no longer one object, it's really two parts that have been sundered, like pre-independent India into India and Pakistan these objects have met with a similar fate.

We need to know more about these great Indus cities, and our knowledge is still growing steadily, but of course the big breakthrough would come if we could read the signs on the seals. We just have to wait. In the meantime, the total disappearance of these great urban societies is an uncomfortable reminder of just how fragile our own city life indeed our own civilization is today.

14.

Jade Axe.

Jade axe, found near Canterbury, England.

40002000 BC.

For most of history, to live in Britain has been to live at the edge of the world. But that doesn't mean that Britain was isolated.

We've explored how 5,000 years ago cities and states grew up along some of the great rivers of the world, in Egypt, Mesopotamia, Pakistan and India. Their styles of leadership and their architecture, their writing and the international trading networks, allowed them to acquire new skills and to exploit new materials. But in the world beyond these great river valleys, the story was different. From China to Britain, people continued to live in relatively small farming communities, with none of the problems or opportunities of the new large urban centres. What they did share with them was a taste for the expensive and the exotic. And, thanks to well-established trade routes, even in Britain, on the extreme outside edge of the Asian/European landmass, they had long been able to obtain what they wanted.

In Canterbury around 4000 BC a supreme object of desire was this polished jade axe. At first sight it looks like thousands of other stone axes in the British Museum collection, but it's thinner and wider than most of them. It still looks absolutely brand new and it's very sharp. It's the shape of a teardrop, about 21 centimetres (8 inches) long and about 8 centimetres (3 inches) wide at the base. It's cool to the touch and extraordinarily, pleasingly smooth.

Axes occupy a special place in the human story, as we first glimpsed at the beginning of this book. The farming revolution in the Near East took generations to spread from there across the breadth of mainland Europe, but eventually, about 6,000 years ago, settlers reached British and Irish shores in skin-covered boats, bringing with them crop seeds and domesticated animals. They found thick forests covering the land. It was stone axes that enabled them to clear the spaces they needed to sow their seeds and graze their beasts. With axes the settlers made for themselves a new wooden world: they felled timber and built fences and trackways, houses and boats. These were the people who would also construct monuments like the first Stonehenge. Stone axes were the revolutionary tool that enabled our ancestors to create in England a green and pleasant land.

Axes like this one normally have a haft that is, they're fitted into a long wooden handle and they're used like a modern axe. But it's quite clear that our axe has never been hafted in fact, it shows no signs of wear and tear at all. If I run my finger carefully round the blade end, I can't feel even the smallest chip. The long flat surfaces are remarkably smooth and still have a glossy, mirror-like sheen.

The conclusion is inescapable. Not only has our axe not been used it was never intended to be used, but rather to be admired. Mark Edmonds, of York University, explains how this magnificent prestige object was made: If you have the good fortune to handle one of these axes the feel in the hand, the balance, the weight, the smoothness you can tell they have been polished to an extraordinary degree. To give that polish it will have been ground for hour upon hour against stone, then polished with fine sand or silt and water, and then rubbed backwards and forwards in the hand, perhaps with grease and leaves. That's days and days of work. It gives the edge a really sharp and resilient bite, but the polishing also emphasizes the shape, allows the control of form, and brings out that extraordinary green and black speckled quality to the stone it makes it instantly recognizable, and visually very striking. Those things may be just as important for this particular axe as the cutting edge.

The most exciting thing about this axe head, however, is not how it has been made, but what it is made of. It doesn't have the usual grey-brown tones that you find in British stones and flints, but is a beautiful striking green. This axe is made from jade.

Jade is, of course, foreign to British soil we tend to think of it as an exotic material from the Far East or from Central America; both the Chinese and the Central American civilizations are known to have valued jade far more highly than gold. These sources are thousands of miles away from Britain, so archaeologists were baffled for many years by where the jade in Europe could have come from. But there are actually sources of jade in continental Europe and, only a few years ago, in 2003 some 6,000 years after our axe head was made the precise origin of the stone it was made from was discovered. This luxury object is in fact Italian.

Archaeologists Pierre and Anne-Marie Petrequin spent twelve hard years surveying and exploring the mountain ranges of the Italian Alps and the northern Apennines. Finally they found the prehistoric jade quarries that our axe comes from. Pierre Petrequin describes the adventure: We had worked in Papua New Guinea, and studied how the stone for the axe heads there comes from high in the mountains. This gave us the idea of going up very high in the Alps to try and find the sources of European jade. In the 1970s, many geologists had said that the axe-makers would just have used blocks of jade that had been carried down the mountains by rivers and glaciers. But that's not the case. By going much higher up, between 1,800 and 2,400 metres above sea level, we found the chipping floors and the actual source material still with signs of its having been used.

In some cases, the raw material exists as very large isolated blocks in the landscape. It's quite clear that these were exploited by setting fire against them, which would allow the craftsmen then to knock off large flakes and work them up. So the sign that's left on the stone is a slightly hollow area a scar as it were with a large number of chips beneath it.

The geological signature of any piece of jade can be precisely identified and matched. The Petrequins found not only that the British Museum axe could be linked to the Italian Alps, but that the readings of the geological signatures are so accurate that the very boulder which the axe came from could be identified. No less extraordinary, Pierre Petrequin was able to track down a geological sibling for our axe another jade beauty found in Dorset: The Canterbury axe head was from the same block as one that was found in Dorset, and it's clear that people must have gone back to that block at different times, it might be centuries apart, but because it's distinctive compositionally, it's now possible to say ... yes, that was the same block ... chips off the old block!

The boulder from which the British Museum axe was chipped 6,000 years ago still sits in a high landscape, sometimes above the clouds, with spectacular vistas stretching as far as the eye can see. The jade-seekers seem to have deliberately chosen this special spot they could easily have taken jade that was lying loose at the base of the mountains, but they climbed up through the clouds, probably because there they could take the stone that came from a place midway between our world on Earth and the celestial realm of gods and ancestors. So this jade was treated with extreme care and reverence, as if it contained special powers.

Having quarried rough slabs of jade, the stone-workers and miners would then have had to labour to get the material back down to a place where it could be crafted. It was a long, arduous task, completed on foot and using boats. Yet big blocks of this desirable stone have been found roughly 200 kilometres (120 miles) away an astonishing achievement and some of the material had an even longer journey to make. Jade from the Italian Alps eventually spread throughout northern Europe some even as far as Scandinavia.

We can only guess about the journey of our particular axe, but our guesses are informed ones. Jade is extremely hard and difficult to work, so much effort must have gone into shaping it. It's likely that first of all it was roughly sculpted in northern Italy, and then carried hundreds of miles across Europe to north-west France. It was probably polished there, because it's like several other axes found in southern Brittany, where there seems to have been a fashion for acquiring exotic treasures like this. The people of Brittany even carved impressions of the axes into the walls of their vast stone tombs. Mark Edmonds considers the implications: Beyond the practical tasks that you can use one of these things for, axes had a further significance a significance that came from where they were found, who you got them from, where and when they were made, the sort of stories that were attached to them. Sometimes they were tools to be used and carried and forgotten about in the process, at other times they would come into focus as important symbols to be held aloft, to be used as reminders in stories about the broader world, and sometimes to be handed on in an exchange with a neighbour, with an ally, with somebody you'd fallen out with, and perhaps in exceptional circumstances, on someone's death, the axe was something that had to be dealt with. It had to be broken up like the body, or buried like the body, and we do have hundreds if not thousands of axes in Britain that appear to have been given that kind of treatment: buried in graves, deposited in ritual ceremonial enclosures, and even thrown into rivers.

That our axe has no signs of wear and tear is surely a consequence of the fact that its owners chose not to use it. This axe was designed to make a mark not on the landscape but in society, and its function was to be aesthetically pleasing. Its survival in such good condition suggests that people 6,000 years ago found it just as beautiful as we do today. Our love of the expensive and the exotic has a very long pedigree.

15.

Early Writing Tablet.

Clay tablet, found in southern Iraq.

31003000 BC.

Imagine a world without writing without any writing at all. There would of course be no forms to fill in, no tax returns, but also no literature, no advanced science, no history. It is effectively beyond imagining, because modern life, and modern government, is based almost entirely on writing. Of all mankind's great advances, the development of writing is surely the giant: it could be argued that it has had more impact on the evolution of human society than any other single invention. But when and where did it begin and how? A piece of clay, made just over 5,000 years ago in a Mesopotamian city, is one of the earliest examples of writing that we know; the people who gave us the Standard of Ur have also left us one of the earliest examples of writing.

It is emphatically not great literature; it is about beer and the birth of bureaucracy. It comes from what is now southern Iraq, and it's on a little clay tablet, about 9 centimetres by 7 (4 inches by 3) almost exactly the same shape and size as the mouse that controls your computer.

Clay may not seem to us the ideal medium for writing, but the clay from the banks of the Euphrates and the Tigris proved to be invaluable for all kinds of purposes, from building cities to making pots, and even, as with our tablet, for giving a quick and easy surface on which to write. From the historian's point of view, clay has one huge advantage: it lasts. Unlike the bamboo used by the Chinese to write on, which rots quickly, and unlike paper, which is so easily destroyed, sun-baked clay will survive in dry ground for thousands of years and as a result we're still learning from those clay tablets. In the British Museum we look after about 130,000 writing tablets from Mesopotamia, and scholars from all over the world come to study the collection.

While experts are still working hard on the early history of Mesopotamian script some points are already very apparent, and many of them are visible in this oblong of baked clay. You can see clearly how a reed stylus has pressed the marks into the soft clay, which has then been baked hard so that it is now a handsome orange. If you tap it, you can hear that this tablet is very tough indeed that's why it has survived. But even baked clay doesn't last for ever, especially if it has been exposed to damp. One of our challenges in the British Museum is that we often have to re-bake the tablets in a special kiln in order to consolidate the surface and preserve the information inscribed on the clay.

Our little beer-rationing tablet is divided into three rows of four boxes each, and in each box the signs typically for this date are read from top to bottom, moving right to left, before you move on to the next box. The signs are pictographs, drawings of items which stand just for that item or something closely related to it. So the symbol for beer is an upright jar with a pointed base a picture of the vessel that was actually used to store the beer rations. The word for 'ration' itself is conveyed graphically by a human head, juxtaposed with a bowl, from which it appears to be drinking; the signs in each of the boxes are accompanied by circular and semicircular marks which represent the number of rations recorded.

You could say that this script isn't really writing in the strict sense, that it's more a kind of mnemonic, a repertoire of signs that can be used to carry quite complex messages. The crucial breakthrough to real writing came when it was first understood that a graphic symbol, like the one for beer on the tablet, could be used to mean not just the thing it showed, but what the word for the thing sounded like. At this point writing became phonetic, and then all kinds of new communication became possible.