The gold ingots are roughly the size of iPhones, and the company gets them from the Nanjing bank. Then then put them through a machine that hammers them, repeatedly, until one gold ingot is nine metres long and as thin as a sheet of paper. Then they hammer them again, and again and again. And when they are small CD-sized roundels of thin gold, they cut them into squares and cut the squares into smaller squares, and then they hammer them again, until they are literally as thin as a cicada’s wings.

Miss Li is part of the process. She has to take a roundel of beaten gold, tease it gently off the paper with a goose feather, and then move it onto a new piece of paper, blowing gently on it to flatten it and move it around.

“It is very difficult training,” she says. “You have to pass exam where you blow middle candle out of three, without blowing out other two. Training for blow job took me eighteen months.”

I nod sagely.

Nanjing used to be called Jinling (Gold Hill), so the gold foil company based here couldn’t resist calling itself Jinling. Mr Ge, who is the sixth generation of his family to oversee Miss Li and her colleagues, takes me around the factory, and we have fun banging on an anvil with hammers, which was the way things were done before they automated so many elements of the process.

He takes me to the showroom, which is a Trumpish extravaganza of gold leaf on everything – gold leaf pianos, gold leaf Buddhas and other tat. Waiting for us there, unexpectedly, is his foreign liaison Viviana, a young Italian artist of some renown, who works with gold leaf in some of her paintings, and has ended up as a part-time greeter for foreign bigwigs who come to talk about painting their toilets gold, or something.

Viviana is very easy on the eye, and I think she would make a striking interviewee as both artist and employee, a welcome change from our usual run of middle-aged men, but the director immediately assumes that she works in another capacity and shouts at me to “stop chatting up the Russian” and to get on my marks ready to interview Mr Ge. He talks for a while about the history of gold leaf in Nanjing, and delicately describes his customers as devout religious believers, and not, say, ghastly billionaires. And that is another day done.

Jonathan Clements is the author of A Brief History of China. These events featured in Route Awakening S05E06 (2019).

In 886, during the last days of the Tang dynasty, the poet Wei Zhuang dropped in on Nanjing, once a great capital, now a forgotten backwater, its walls in disrepair, and its canals choked with weeds. He wrote:

Drizzle on the river, and the reeds grow high / The Six Dynasties are but a dream, and the birds call in the sky / Cares not the willow by the walls / Ten leagues around in the smoky mist.

Nanjing has improved a lot in the sun. The remains of the walls still bracket a sizeable chunk of Xuanwu Lake, just to the north of the old city, and are dotted with Ming- and Qing-era cannons poking from the crenellations. The park is nice with autumn trees and the Jiming temple looms above outside the city walls. So we ought to get some nice shots that make Nanjing look less like an urban jungle in the rain, and more like a pleasant bit of park life. The Propaganda Bureau should be pleased, as well they should be when the woman who mans the gate to the city walls insists on taking a photograph of us filming the sign so she can send it to her boss.

We put on the most ridiculous charade of setting up a shot by the sign, with me not bothering to take off my sunglasses, Mickey the sound man not bothering to boom, and Eric the cameraman not even starting the camera.

“Are we rolling?” calls the director.

“Nope!” says Eric, with a thumbs-up.

“Action!”

“I’m standing here next to a sign,” I say earnestly, “while a woman in a mustard yellow puffa jacket films me with her phone.”

“And cut!”

Michelle rushes in with her clapperboard and brightly says: “Waste of Time Fake Thing, Take One!”

We lurk around the walls for a while, which are picturesque but thick with flies, and then head off to the Longjiang Shipyard Ruins.

The layout will be familiar to anyone who has been to London Docklands. Three long strips of water, each the size of an airport runway, run in parallel through what is now billed as a park. But this park was the site of the Ming-era shipyards where the Treasure Fleet was built, and from where it set sail, down the Yangtze and as far as Africa. The lakes are all that remains of docks four, five and six. One, two and three, of similar size, are buried somewhere under the nearby housing estate.

Everybody knows the story of Zheng He, or at least thinks they know: the boy captured at the fall of Yuan-era Yunnan, castrated and shipped off to Beijing aged ten as a slave to the Yongle Emperor. Originally named Ma, short for Mohammed, for he was a Muslim, he was renamed Zheng in honour of his spirited defence of the Zhengcunba reservoir during the dastardly Yongle’s grab for power. Eventually put in charge of the Treasure Fleet, he set sail for the south and the west in 1405 on the first of what would become seven voyages, designed to tell all the natives in far-flung kingdoms just how awesome China was. When he came home, he turned up with a giraffe, so everybody was happy. Just for kicks, I pace out the rudder in the museum, which is 14 metres long, with a flappy bit that comprises the bottom six metres. The people from Propaganda, ever willing to say no to everything, have told us that we can film in the dockyards but that we can’t film the replica ship at one end of it, because it might be moved by the time our film broadcasts. Or it might not.

Suspicious, I pace out the length of the ship and find it to be 73 metres – a perfectly reasonable size for a Chinese trading galleon, but nothing like the aircraft-carrier sized behemoths claimed by some of the world’s more breathless popular historians. The shipyards are very long indeed, but even the artists’ impressions in the nearby museum show several ships being built at once in any single dock. They were not, and never were intended to hold single giant galleons. If they were, there would not have been enough turning space to get them out of the gate and into the Qinhuai River to sail down to the Yangtze and out to sea.

Jonathan Clements is the author of The Emperor’s Feast: A History of China in Twelve Meals. These events featured in Route Awakening S05E06 (2019).