The first emperor: the megalomaniac who united China

Qin was a kingdom in the north-west corner of China, a land of horse-rearing and bounty-hunting. Selective breeding meant that larger horses were now available, allowing soldiers to ride into war on horseback, liberating them from expensive, unwieldy chariots.

The military might of the Qin was matched only by its brutality. One famous general, called Bai Qi, is reputed to have killed more than a million soldiers and seized more than 70 cities. In 278BCE, he led the Qin army to victory against its biggest rival from the Yangtze south, the Chu. He then went on to defeat the Zhou, the nominal kings of China, at the Battle of Changping in 260BCE. After this battle he had more than 400,000 prisoners of war slaughtered by burying them alive.

Civil administrators were no less harsh. Shang Yang, is credited with reforming the running of the Qin kingdom, turning it from a disorganised tribal power into a slick, effective, military machine. With the support of the then ruler Qin Xiaogong (381BCE-338BCE), Shang Yang was able to put into practice his belief in the absolute rule of law. For him, loyalty to the state was always superior to loyalty to the family. His reforms included stripping nobles of their lands and giving them instead to generals as a prize for victory in war. He put great emphasis on agricultural reform, so that the land could support more people and feed more soldiers. Farmers who met government quotas for supplying food were rewarded with slaves.

Shang Yang's reforms were later codified into a book of law called The Book of Lord Shang. Qin became the strongest state amongst the Seven Kingdoms. The climax came with the rise to power of Ying Zheng as ruler of Qin. After defeating the last independent Chinese state, Qi, in 221BCE, Ying became the first emperor of all China, ruling from 221BCE to 210BCE as Qin Shi Huang, having renamed himself after the divine rulers of Chinese mythology.

With the assistance of his prime minister, Li Si, Qin Shi Huang rewired China into an awesome centralised powerhouse. Regional rulers were sacked, and in their place he appointed loyal civil governors to each of 36 new civil regions. Alongside them military governors were appointed, and a team of inspectors roamed the country to ensure none of them overstepped the mark. Governors were rotated every few years to prevent any one of them from building up a regional power base. All this was an extension of what Shang Yang had implemented across the kingdom of Qin more than 100 years before.

In 213BCE, Qin Shi Huang ordered what is called the Great Burning of Books, suppressing freedom of speech in an attempt to unify all thought and political opinion. Hundreds of thousands of books were burned, many of them originating from the philosophies of the Hundred Schools of Thought. All books were banned, except for the legal works that promoted supreme control of the state. Anyone found discussing illegal books was sentenced to death, along with his family. Anyone found with proscribed books within 30 days of the imperial decree was sent north to work as a convict on the construction of the first Great Wall of China.

A massive canal, begun in Qin Shi Huang's father's reign and built by a brilliant engineer called Zheng Guo, was completed in 246BCE. It unlocked opportunities for rice-growing further north, and provided the Qin Dynasty with an almost limitless supply of food with which its armies and people could gain an unassailable position of strength.

Finally, the new imperial government standardised just about everything that could make running a large centralised empire easier – from the characters used in handwriting to the width of axles for carts so they would run more smoothly in the ruts of imperial roads. Edicts, some of which survive, were inscribed on the sacred Mount Taishan in Shandong to let heaven know of the new unification of the Earth under a single, all-powerful emperor.

Towards the end of his life, Qin Shi Huang became obsessed with finding an elixir that would make him immortal. He eventually died during a tour of eastern China in 210BCE after swallowing mercury pills which his advisers believed would give him everlasting life.

For 2,000 years no one knew where he was buried. Then, one day in 1974, some well-diggers struck an unusual object buried several feet underground. What they found led to one of the most incredible archaeological discoveries of all time. It was an enormous royal tomb, some three miles across, containing a terracotta army of more than 8,000 life-size soldiers, designed to defend the Emperor Qin Shi Huang in the afterlife.

More than 700,000 workers were involved in its construction. Each soldier is an individual, hand-crafted work of art, originally equipped with bronze spears and bows and arrows. The army is arranged in battle formation, supported by 600 clay horses and more than 100 life-size working wooden chariots.

Although Qin's dynasty crumbled only a few years after his death, thanks to the hatred and vitriol that accompanied his life's work, his achievement was complete. He didn't just bring about the unification of seven warring kingdoms into the largest empire on earth, he created a top-to-bottom model for imperial administration, from the principles of its ruling culture down to the nitty-gritty of the plumbing needed to make it all work in practice.

Rice, silk and iron provided both the appetite for expansion and the means of conquest to create the largest and most enduring human power on Earth. Supreme command over nature turned these ancient people into an ingenious and unassailably robust civilisation for thousands of years to come.