HONG KONG -- A wristwatch once owned by China鈥檚 last emperor, Aisin-Gioro Puyi, has sold for $6.2 million at a sale in Hong Kong.

The eye-watering price tag is partly due to the rarity of the Patek Philippe Reference 96 Quantieme Lune, one of just eight known to exist. But according to Phillips auction house which handled the sale, the seven-figure sum is also down to the 86-year-old watch鈥檚 remarkable history 鈥 one that saw it taken to Siberia during the former ruler鈥檚 five-year imprisonment in the USSR.

The 1.2-inch-diameter platinum timepiece features an Arabic numeral dial, pink gold hands and a 鈥渕oon phase鈥 function that shows how visible the moon is from Earth at any given time. Some of its internal mechanisms date to 1929, though the model was not sold by Patek Philippe 鈥 a Swiss watchmaker known for fitting complicated movements into slim cases 鈥 until 1937.

It is not known how Puyi acquired the timepiece, though records show it was initially sold via a luxury store in Paris. Phillips added that historical documents prove the former emperor took it with him to a Soviet prison camp in Khabarovsk. He later gifted it to Georgy Permyakov, a fluent Mandarin speaker who served as his tutor and Russian translator during his time in detention.

Puyi, whose life formed the basis of the Oscar-winning 1987 movie 鈥淭he Last Emperor,鈥 ascended the throne as a mere toddler in 1908. He was forced to abdicate less than four years later when a republican revolt overthrew the Qing dynasty, though he was permitted to continue living in the imperial palace in Beijing (and was briefly reinstated as emperor in 1917).

In 1924, he fled Beijing and formed an alliance with Japan, which later installed him as the emperor of its puppet state, Manchukuo, in northeast China鈥檚 Manchuria region. After Japan鈥檚 defeat in the Second World War, Puyi was captured by Soviet forces and held as a prisoner of war. According to Phillips, he gave the watch to Permyakov in 1950, just before the former emperor returned to China to face trial for war crimes.

According to a press release, Phillips spent three years researching the object鈥檚 history and confirming its provenance 鈥 a process that Thomas Perazzi, the auction house鈥檚 head of watches for Asia, described in a statement as an 鈥渦nprecedented research project with a worldwide team of watch specialists, historians, journalists and scientists.鈥

In its catalog listing, Phillips cites Puyi鈥檚 nephew Yuyan (who was incarcerated alongside him) recalling in his memoirs that his uncle wore the watch 鈥渄ay to day鈥 while in Manchukuo. The catalog also says that Puyi had previously gifted the watch to his nephew, but later asked for it back in order to give it to Permyakov.

Almost a decade after returning to China, Puyi was pardoned and lived as a civilian in Beijing until his death in 1967. Permyakov, meanwhile, kept the watch until he died in 2005, after which it was passed to his heirs before being consigned to Phillips by its current owner in 2019. The timepiece has already been displayed in New York, Singapore, London, Taipei, and Geneva before it returned to Hong Kong, where it sold at Phillips鈥 new Asia headquarters on May 23.

The watch was offered alongside several other of Puyi鈥檚 former possessions. Among them were 15 watercolours, attributed to Puyi鈥檚 brother-in-law Gobulo Runqi, and a red paper fan also given to Permyakov, featuring a poem inscribed by the former emperor.

One of Puyi鈥檚 manuscript notebooks, which Phillips says 鈥減rovides a never-before-seen glimpse into (his) mind,鈥 was also sold alongside his copy of Confucius鈥 鈥淭he Analects,鈥 with the two items together fetching over $121,500.

The sale will be followed by a two-day watch auction at Phillips featuring some 240 timepieces. Among the historically notable items featured is a limited-edition Omega Speedmaster Apollo XI 1969 once presented to NASA astronaut Charles 鈥淧ete鈥 Conrad Jr., the third person ever to walk on the moon.