"With his vivid brush stroke, Shining restored to me my long-lost youth," the emperor wrote in an amused tone, calling the painter by his Chinese name, Lang Shining. "Who is this? Those who come across it must have wondered."

In the painting, a middle-aged Qianlong, again dressed in Han style, is holding a branch of plum flowers in the company of another man. The deep blue background - an unusual touch that belies the painter's "foreignness" - adds a surreal sense and helps highlight the figures in the foreground.

Le Qiaoqiao, a researcher with the Zhejiang Museum, says: "Between these three paintings is a man who ruled over one of the world's largest empires of his time, who is ever conscious of his own cultural legacy - Qianlong pushed for the standardization of the Manchu language - and who, at the same time, fell genuinely for another culture and art tradition, which he embraced and promoted tirelessly."

To Ma, of the Palace Museum, the exhibition could not be more timely, given how misconstrued the emperor is today. "His taste is questioned," she says, referring to the emperor's love of intensely crafted and often heavily embellished pieces, a love that contrasted with the pared-down aesthetic of his father Emperor Yongzheng.

"However, it appears to me that what the emperor really was after was not any particular aesthetic, but a cultural legitimacy and a sense of undisrupted continuity," she says, referring to Qianlong's reinterpretation of Shang Dynasty (c. 16th century-11th century BC) bronze ware, in dark green jade.

"It's true that he rated art works from history and left countless stamps on them, sometimes obscuring the original work. And it's true that such practices say a lot about his personal pride. But this pride drove him to collect and preserve with even more fervor. And we all thank him for that."