History becomes legend. Legend becomes myth.

At best, historians hope that at least a kernel of truth lingers lost among centuries’ worth of embellishment, propaganda, and hype.

But the gap between fantasy and reality has narrowed dramatically when it comes to what we know of China’s tyrannical first emperor, Qin Shi Huang.

Evidence is mounting that a 15-ton casket pulled from the outskirts of his fabled tomb last year belongs to his noble, yet tragic, son Prince Gao.

Recent evidence is adding weight to the idea that Emperor Qin’s renowned tomb contained a massive, lifelike representation of the expansive empire he ruled.

Quicksilver strands

China’s most famous historian, Sima Qian, lived from 145BC to 86BC.

Emperor Qin died in 210BC. So well over a century had passed by the time Sima penned his epic “Shiji – the Records of the Grand Historian.”

That’s plenty of time for political spin and fanfiction to have taken their toll.

His story certainly sounded fanciful.

Throughout his reign, Emperor Qin was obsessed with finding the key to immortality. However, none of the alchemists, explorers, magicians, or priests he employed could uncover the secret.

Luckily, the first thing he had done when taking the throne at age 13 was order the construction of an immense mausoleum.

Sima wrote that 700,000 workers had laboured 38 years to complete the funerary complex at Mount Li in Shanxi province, north-central China.

“Imitations of palaces, scenic towers, numerous officials, along with rare artifacts and extraordinary items, were gathered to fill the tomb,” he noted.

“Mercury was used to fashion imitations of the hundred rivers, the Yellow River and the Yangtze, and the seas, constructed in such a way that they seemed to flow. Above were representations of all the heavenly bodies, below, the features of the earth.”

The first modern evidence that some of this may be true came in 1974.

Farmers digging a well stumbled on the pottery statue of a soldier. Archaeologists soon found an entire terracotta army, exact in every minor detail.

“As further excavation revealed the extent of the emperor’s mausoleum, with offices, stables and halls, along with clay figures of officials, acrobats and labourers and life-size bronze animals, it became clear that the Han dynasty historian Sima Qian, writing in second century BC, hadn’t been exaggerating after all,” writes the Royal Society of Chemistry’s Philip Ball.

But what interests chemists and archaeologists alike is mercury.

Mercury (Shui yin) translates as “water silver” in Chinese.

Toxic truth

Emperor Qian’s central mausoleum has been surveyed, but not excavated.

It’s some 1,640 square feet. And at its heart is an 262 ft by 164 ft chamber.

At that scale, the mythical map would have to be enormous.

But soil samples taken in the 1980s revealed unnaturally high levels of mercury. More recent gravity-mapping and electrical resistivity tests have been more conclusive.

“Measurements of soil resistivity have revealed another intriguing feature,” writes Ball. “They show a so-called phase anomaly, which is produced when an electrical current is reflected from a conducting surface, such as a metal. Could this be a sign of mercury?”

Some Chinese archaeologists believe these reflections roughly correlate with the positions of China’s major river systems. Others aren’t so sure.

What is sure, now, is that the production of mercury was in full force at the time of Emperor Qian.

Chinese state-controlled media reports the chemical makeup of mercury recovered from the mausoleum matches that found in the cinnabar mines of Xunyang, 75 miles away. Once used as a pigment and traditional medicine, smelting this mineral would release the mercury bound within it.

New surveys of Xunyang have found three ancient mining sites that produced the mineral along the Shengjia River valley. All three contain artefacts dating from the Neolithic era to the Qing Dynasty.

The Global Times reports up to 100 tons of mercury has been detected in the mausoleum.

“Mercury has excellent insulation properties, forming a sealed thermal barrier within the tomb, while also having antibacterial effects,” the report reads.

“Therefore, scientists widely surmise that the mercury in the tomb was used for preservation and antitheft purposes.”

Researchers have also long suspected the importance of cinnabar.

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“Chinese legend tells of one Huang An, who prolonged his life for at least 10,000 years by eating mercury sulphide (the mineral cinnabar),” writes Ball.

“The First Emperor was said to have consumed wine and honey laden with cinnabar, thinking it would prolong his life”.

Game of Thrones

Like Emperor Qian’s mausoleum, Chinese archaeologists have been nervous about picking apart the burial casket excavated last year.

Work continues, slowly.

The 15-ton casket appears untouched by grave robbers.

Therefore, like the tomb of the Egyptian Pharaoh Tutankhamun, it’s likely to offer an immense insight into royal life in that era.

Its casing has largely collapsed. However, this has revealed approximately 6000 bronze coins, as well as jade, silver, and gold figurines. A complete set of cutlery and porcelain crockery has been recovered, as have pieces of armour and weapons.

Initially, its owner was assumed to have been a “notable warrior”.

Now speculation is centring on one of the First Emperor’s many sons.

Emperor Qian’s first son, Fusu, was supposed to inherit the throne. But royal court machinations eventually whittled their way through the succession until Prince Hu Hai rose to the top.

Prince Gao knew he was doomed. So he resolved to publicly confront his younger brother to demand an honourable death and the right to be buried with his famous father.

Or so the story goes.

“For the first time in 2000 years … we have a chance to figure out if what Sima Qian wrote is correct,” says Oxford University associate professor Hui Ming Tak Ted.

So far, the evidence is circumstantial.

Part of the skull has been recovered. Testing shows it to belong to a healthy male, aged between 18 and 22 years old.

And the youngest objects identified so far belong to the late Qin period – meaning they fit the timeline of the emperor’s death.

But a royal signet or personal seal would have to be recovered before the burial’s identity is confirmed.