"We want to invigorate and enlighten people to ideas, rather than simply inform historically." The 2200-year-old warriors have become an iconic shorthand for ancient China, and one of the country's most popular tourist attractions, yet the vast tomb where they were discovered, outside the city of Xi'an, remains largely unexplored, an enduring mystery, the body of Qin himself still entombed in his city-sized mausoleum. Discovered by chance in 1974 by local farmers digging a well, Qin's sprawling burial complex brought to light a wealth of knowledge about Chinese daily life from the time; until then, knowledge of the Qin dynasty was derived from just a few historical texts. The site is considered one of the world's greatest archaeological finds. Known as the First Emperor, he was born in 259 BC, becoming king at 13 of Qin, then one of six states comprising ancient Chinathat had been warring for more than 200 years. Qin managed to conquer them all, unifying the country and proclaiming himself emperor. He established a national road system and built the Great Wall, and standardised language, currency and weights and measures.

Sword blade with inlaid openwork hilt, Eastern Zhou Dynasty, 770–476 BCE in gold, iron and calaite. Credit:Baoji City Archaeological Team But he was also something of a tyrant and obsessed with attaining immortality, a popular concern of rulers of ancient cultures. As emperor, Qin was able to take his quest to reign in the afterlife to extremes, beginning work on his mausoleum more than 30 years before his death. It's believed a team of up to 700,000 workers - many conscripted slaves - created the massive mausoleum for Qin, spread out, beneath the ground over about 56 square kilometres, and designed to mirror the world above. His tomb was guarded by the army of life-sized terracotta warriors, standing in silent formation, each weighing 160kg, and standing 1.8 metres tall, of varying military ranks, and carrying fully functional weapons, made of bronze; dozens of spears, lances, swords, crossbow triggers and as many as 40,000 arrow heads have been recovered. The warriors also feature different facial expressions and hairstyles, (thought to have been based on real people) and are believed to number up to 8000; to date, some 2000 have been excavated and painstakingly restored by a team of archaeologists who work permanently at the site, where several hundred of the warriors are on display, still in the pits where they were buried. The site attracts up to 40,000 tourists a day in peak season.

Other pits have revealed even more luxurious accoutrements, including a facsimile of a "pleasure garden", populated by life-size bronze waterfowl and terracotta musicians, and even troupes of acrobats. Tantalisingly, there is much more that has never been disinterred; as well as a desire to respect the relics, it's believed much of the tomb is too difficult to enter, having been booby trapped to prevent tomb raiders. Then there's the presence of mercury; beneath the ground it's believed a system of flowing liquid mercury, used to recreate the natural waterways of the real China above ground still flows, while the tomb's ceiling is thought to be painted to represent the heavens above. At the site, which attracts up to 40,000 tourists a day in peak season, a permanent team of archaeologists continues to work on excavation. Ma Shengtao, who has worked at the Mausoleum Site Museum since 1999 and is the director of the collection management department, explains that there is still much to learn from the site; excavation is just a small part of the job. An unarmored officer from the tomb, dating from the Qin Dynasty 221–207 BCE.

Working on reconstructing the warriors is time consuming, he says. "Excavation is not a big part of the work right now," he says through an interpreter. "The main work right now is investigation and searching historical articles." As for what is yet to be revealed inside the main chambers, he says it may remain unknown for years yet. "For now ... exploring the three pits is a lot of work and the mausoleum is the biggest treasure," he explains. "The policy here in China is to protect and maintain, so right now we are doing that - we are not going to dig there." Despite the promise of Indiana Jones-style treasure and further insights into life in third century China, protection of these cultural relics outweighs the curiosity. "My duty is to protect (the tomb)," says Shengtao. "That's much more important that my curiosity."

Alongside eight warriors and two full-size horses, the NGV is exhibiting earthenware, bronze arrowheads and replicas of two half-scale bronze chariots decorated with gold and silver, each drawn by four horses. These were found six years after the warriors, squashed completely flat, and reconstructed. A handful of the warriors were exhibited at the NGV in 1982, just a few years after their discovery, (in the first show outside of China), but both the scale and breadth of this exhibition eclipses that one, says Crothers. "That was really just the surprise and this amazing discovery, but in the 36 years since that, and the 44 since the tomb's discovery, there's been a huge wealth of extra material found in the region, many more significant finds from other historical periods," he says. A bronze sculpture of a tiger mother with cub in its mouth from the Western Zhou Dynasty, 1046–771 BCE. "We are extending the role of the artistic creations; as well as tombware, there's carved jade, bronzeware with amazing design and decoration, and then Cai's response to these objects."

Many finds from the Han dynasty, which followed Qin's reign, will be seen for the first time, including very different terracotta figures from the tomb of the fourth Emperor Jing, which have never been seen here before. Jing's tomb held thousands of half-metre tall, nude figurines made with wooden arms as well as thousands of animals. Like Qin's soldiers, the animals - dogs, horses, sheep, oxen and chickens among them, all with different facial expressions, were found standing in formation. The works of Cai Guo-Qiang will be intermingled with these ancient treasures. The Chinese born, New York-based artist is best known for his aerial pyrotechnic displays and gunpowder artworks, made by detonating large trails of gunpowder. Cai's work combines traditional Chinese history and philosophy with contemporary subjects. Mixing the ephemeral with installations, video and performance, his works have been exhibited around the world, including at the Metropolitan Museum of Art and the Guggenheim in New York, the Museum of Contemporary Art in LA and Beijing's Museum of China. He also directed the visual effects for the 2008 Beijing Olympic ceremony.

Cai's work combines traditional Chinese history and philosophy with contemporary subjects, particularly through his materials - for this exhibition, he has worked with traditional Chinese mediums of silk, gunpowder, paper and porcelain. His works include Transience II (Peony), a massive gunpowder painting on silk measuring some 31 metres in length, which will be hung in a circular fashion, creating a 360-degree experience. Suspended above this will be a mammoth installation of 10,000 porcelain birds, also coloured by gunpowder explosion. An aerial view of Transient II (Peony) shortly after completion, created by Cai Guo-Qiang in Melbourne earlier this year. Credit:Simon Schluter Speaking through an interpreter in March, when he was in Melbourne creating the works, Cai said he was very moved when he first visited the tomb as a college student. "But when I saw an exhibition overseas with only a few on display, it was less powerful; the spirituality isn't conveyed as deeply," he says. "So when NGV decided to make a parallel exhibition ... I created the murmuration of the 10,000 birds, which are like lingering spirits of the underground army coming up into the sky of the gallery space."

The exhibition also features a sculpture of porcelain peonies; the peony is considered China's unofficial flower. "But why do they always paint the peony in its emergent state, or blossoming state," Cai asks. "Why didn't they paint any of the withering or dead flowers? For this exhibition, I visited Luoyang, the Chinese city known as the 'city of peonies', close by to the mausoleum of the Qin emperor. "But I arrived late and missed the blossoming season of the peony - all the petals had fallen on the ground and I was so touched by the layers and layers of petals - I portrayed that sentiment at the end of the painting." Cai Guo-Qiang, Transience I (Peony) 2019 (detail). © Cai Guo-Qiang From the fragility of petals to gunpowder, all of Cai's references speak to the exhibition's overarching theme of immortality; gunpowder, made from minerals that take hundreds of thousands of years to form, was discovered by the Chinese in their search for an elixir for immortality.

"The literal translation of the word for gunpowder is 'fire medicine'," explains Cai, who uses the material to explore the relationship between the ephememeral and the immortal. "Explosions are a very primal, primordial act, a natural act," he says. Cai believes that his creating a dialogue with tradition and history energises his own work. "The NGV exhibition gave me an opportunity to look at my own culture to see how meaningful it is. It's unusual to interact with such great Asian art artefacts, but I think China needs change - the exhibition will be helpful to bring changes," he says. "And the real explosions do not come from material - they come from thoughts."