After successfully chasing the Mongols out of China, the first emperor of the Ming dynasty, Hongwu, tried to erase his humble, rebellious origins by aspiring to be the perfect ruler. And the perfect emperor needed an ideal capital, so he planned one out in Nanjing. The Nanjing Museum is set in the grounds of his palace, a Forbidden City manqué climbing up the side of a hill with a view of the city walls. And since it’s Monday and the museum is closed to the public, we have it to ourselves except for the fidgeting security guards, and a man from the propaganda office, who is putting a brave face on the fact that he is incredibly bored.

Nanjing’s history goes back to the Stone Age, although the museum concentrates on those moments in Chinese history when it was a capital. When the Han dynasty fell in 220 AD, China spent 350 years in a state of disunity, and Zhuge Liang, a ministerial adviser to one of the upstart kingdoms, recommended Nanjing as the ideal location for capital. It had, he said, mountains around it like a crouching tiger and a coiling dragon, and the river Yangtze acted as a natural moat. When northern China fell to barbarian invaders, the nomads couldn’t make it south of the Yangtze, turning Nanjing into a bastion of old culture and a guardian of Chinese heritage.

I have to do pieces to camera in front of the museum’s various displays – Nanjing has been a sort of capital of China for several cumulative centuries, but for most of those times, it was in one of the squib dynasties of the Dark Ages, when it was only really the capital not of an empire, but of a glorified kingdom in the lower Yangtze area. When even educated foreigners are unlikely to be able to name half a dozen major Chinese dynasties, it is tough to run through the likes of the Liu Song, the Chen and the Southern Qi, none of which lasted for more than a few decades, but all of which were centred on Nanjing, quite probably the greatest city in the world at the time. I pick a giant stone pixiu, a chimera-like mythological beast from the squib emperors’ tombs, as a means of pointing out that they achieved some big things and had an enduring culture, even if the family at the top switched around a few times.

I am actually a huge fan of the Six Dynasties — I love it as one of those neglected periods in Chinese histories, and I am a sad enough Six Dynasties nerd that I could indeed be found on the day of the release of the Cambridge History of China: Six Dynasties, waiting outside the Cambridge University Press bookshop for it to open. Good job, too, because they only had one copy in stock of their new £115 monster, so I got in there ahead of the rush.

We point the camera at ceramic, open-mouthed rhinos, made as bespoke piss-pots for Six Dynasties emperors, as well as fragments of Nanjing’s famous Porcelain Tower, a diorama of the old Yuecheng (Fortress of the Viet) built on the future site of Nanjing by the king of Wu to watch over the conquered 5th century BC kingdom of Yue. The security guards lurk glumly, ordered to be on their feet whenever we are around, and hence forced to be on their feet all day.

A bunch of them sit around in their office smoking fags, leading to the fantastically Chinese moment when their closed circuit TV monitors show our director lighting up behind the toilets in the park, and they rush out to tell her that the whole facility is Non-Smoking. Except, apparently, their office, which has so much smoke billowing out of it that you would be forgiven for thinking it was on fire.

The curator Wu Tian starts off a little timid and unsure of himself. But we get him to show us some of his favourite pieces in the museum, and he starts talking with true passion and excitement about truly weird items. One is a bit of road with ruts worn by four hundred years of ox-carts. Another looks like a mini bedpan, but turns out to be a Six Dynasties iron for smoothing clothes flat. Another looks like half a toilet seat on legs, but is instead a sort of arm rest for people on divans in a culture that has yet to invent the chair.

“I suppose not,” I wonder aloud, “because after all, the chair is a Song-dynasty innovation.”

Mr Wu stands bolt upright, as if poked with a cattle prod. Not for the first time on this shoot, the fact that I am not only listening, but can say something relevant in Chinese makes his eyes stick out on stalks, and suddenly he is twice as animated and excited. The interview goes swimmingly well, since he has worked out that I am not some fat white sock puppet, but an actual historian who knows his Han from his Ming. So he chats excitedly about Dark Age hairstyles and roof tiles, and saves the best till last.

“Now this, he says, “is my favourite. We found it smashed into a hundred pieces in a Nanjing grave, and we put it back together. It’s a glass cup, from a time when China didn’t have any glass blowers. We think it came from the Eastern Roman Empire, by sea, and ended up in Guangzhou, from where it made its way north to Nanjing as some sort of curio to impress visitors. The grave was a wealthy merchant’s, but this isn’t the only Roman glass we’ve found in Nanjing. It’s actually the twelfth.”

Camera A on the interviewee, B-roll on the interviewer, me interjecting with actual questions that make it clear we are not some bored school party fubbing with our phones, but a bunch of people who have come to Nanjing specifically to talk about the Six Dynasties, the squib dynasties that everybody usually ignores. Mr Wu is very pleased, and thanks us profusely for actually knowing what he is talking about. I get the feeling it’s a rare occurrence.

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