An exquisite 18th century imperial Chinese musket made for the Qianlong Emperor (1711-1799) is set to auction in London in November.
The piece is expected to make around £1m-1.5m ($1.3m-1.9m).
Imperial muskets are very rare objects, meticulously crafted from the finest materials by some of the nation's most skilled craftsmen.
This example features gold and silver decorations and displays motifs derived from Zhou dynasty (1046-246 BC) bronze vessels.
The Qianlong Emperor was a keen hunter and used his guns regularly.
He extolled the musket in his writings: "…an Emperor must rely on divine appliances to hone martial skills and demonstrate masculine magnanimity, and the musket is wonderfully efficient and pleasing."
The lot is the most important of a group of seven imperial muskets made for the emperor.
It's inscribed with the characters te deng di yi, meaning Supreme Grade, Number One.
Robert Bradlow, sotheby's senior director of Chinese works of art, said: "This remarkable object epitomises the pinnacle of imperial craftsmanship during the Qing dynasty.
"The gun's historical importance cannot be overstated - it ranks as one of the most significant Chinese treasures ever to come to auction."
The lot's historical importance and spectacular design could see it substantially exceed its estimate when it crosses the block on November 19.
A recent sale of lots from the Qianlong emperor's personal collection included a guqin (a kind of zither), produced to a similarly high standard, that made $7.1m.
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