Latest / Trade Routes That Changed Human History Forever — Fexingo History / The Rhubarb Root: Silk Road's Forgotten Trade Boom
Transcript
- Lucas: So we've talked about pepper, nutmeg, silk, porcelain — the glamour goods of the old trade routes. But there's one commodity that was almost as valuable as silver in some eras, and it's a plant you probably have in your garden today. Luna: Wait — rhubarb? The pie filling? Lucas: Exactly. But not the strawberry-rhubarb kind. I'm talking about the dried root of Rheum palmatum and Rheum officinale — two species native to the highlands of Gansu and eastern Tibet. For over a thousand years, that root was one of China's most tightly controlled exports, and it absolutely dominated the pharmacopoeias of the Islamic world and later Europe. Lucas: See, rhubarb root is a powerful purgative — it contains anthraquinones that stimulate the bowels. In medieval medicine, where humoral theory ruled, anything that could reliably purge the body was considered a cornerstone of treatment. And Chinese rhubarb was the gold standard. Luna: So it wasn't about taste at all. It was medicine. Lucas: Entirely medicine. And it wasn't cheap. In the 9th century, a pound of good rhubarb could fetch as much as a slave in the markets of Baghdad. The Abbasid caliphs imported it by the ton. The famous physician Ibn al-Baytar, writing in the 13th century, devoted an entire chapter to rhubarb in his Compendium on Simple Medicaments and Foods, calling it 'the remedy for obstructions of the liver.' Luna: So how did it get from Tibet to Baghdad? Lucas: That's the fascinating part. There were multiple routes. The classic Silk Road route ran from the rhubarb-growing regions in Gansu and the Kokonor region — that's around Qinghai Lake — west to Kashgar, then over the Pamirs to Samarkand and Bukhara, then down through Merv and into Persia. From there, it went to Baghdad and Basra, then by ship to the Red Sea and into Europe. Lucas: But there was also a northern route: through the Tarim Basin, up to the steppes of what is now Kazakhstan, then across the Volga to the markets of the Khazars and the Rus. That route fed into the Amber Road networks we talked about in episode 60. Luna: So rhubarb was moving on the same roads as silk and slaves. Lucas: Exactly. And the Chinese authorities were very aware of its value. During the Ming dynasty, the government tried to control rhubarb exports as a strategic good — they knew that the Tibetan tribes and the Mongol khans wanted it, and they used it as a bargaining chip. There's a famous story from the 16th century: the Ming court actually cut off rhubarb shipments to the Mongols as a form of economic warfare, hoping to cause constipation and illness among their cavalry. Luna: Wait, really? That's… a weirdly specific weapon. Lucas: It sounds absurd, but it was taken seriously. The Mongol leader Altan Khan actually complained in a letter to the Ming emperor about the lack of rhubarb, saying his people were suffering. And the Ming court used that leverage in negotiations. But it wasn't just the Mongols — European demand exploded in the 16th and 17th centuries, and that's where the story gets really interesting. Lucas: By the 1600s, rhubarb was one of the most expensive drugs in European apothecaries. London, Amsterdam, Paris — every major city had a rhubarb shortage, and the price was astronomical. The problem was that European supplies came through Ottoman and Persian middlemen, and they were often adulterated with other roots. Luna: So how did Europe try to break that monopoly? Lucas: Botanical espionage. The Dutch East India Company — the VOC — was obsessed with getting live rhubarb plants or seeds out of China so they could cultivate it in Europe or in their colonies. They sent agents into the interior of China disguised as merchants, trying to acquire the seeds. But the Chinese guarded the plant carefully — they knew the secret was in the specific species and the growing conditions. Lucas: The man who finally cracked it — partially — was a Dutch botanist named Jakob Breyne. In the 1680s, he obtained dried rhubarb roots from some VOC traders and managed to germinate them in the Leiden botanical garden. But the plants he grew turned out to be a different, less potent species. It took another hundred years before European botanists identified the true Rheum palmatum from specimens collected in China by missionaries. Luna: So the VOC never really broke the Chinese monopoly? Lucas: Not completely. Even when they started cultivating rhubarb in the Cape Colony and later in Europe, the quality never matched the Tibetan and Gansu root. The climate and soil were different. So the trade continued well into the 19th century, with Chinese rhubarb still commanding a premium. It was only with the development of synthetic laxatives in the 20th century that the trade finally declined. Lucas: You know, this whole story — the value of a bitter root, the lengths people went to control it, the espionage — it really shows how non-obvious goods can drive history. And it makes me think about how we support the work that goes into uncovering these stories. Luna: Yeah, I feel that. It's easy to take for granted all the research that goes into each episode. Lucas: If this episode was worth a cup of coffee to you — honestly, that's the link. Buy me a coffee dot com slash fexingo. Just a small thing that keeps the show ad-free and independent. Luna: And it really does help. So anyway — back to rhubarb. You mentioned the Mughals also had a role? Lucas: Yes! The Mughal emperors, especially Akbar, were big consumers of rhubarb. They imported it from Central Asia and also tried to cultivate it in Kashmir. The Mughal court physicians, like the famous Hakim 'Ain al-Mulk, wrote about the superiority of Chinese rhubarb over the local varieties. And the Mughals actually controlled one of the key transit routes through the Khyber Pass — which we covered in episode 57 — so they could tax the rhubarb caravans heavily. Luna: So rhubarb was funding empires, not just curing constipation. Lucas: Exactly. And it wasn't just the Mughals. The Safavid dynasty in Persia also relied on rhubarb revenue. The shahs would grant special trading licenses for rhubarb caravans, and the crop was so important that it appears in tax records from Isfahan and Shiraz. One document from 1680 shows that a single caravan carrying rhubarb from Kashgar to the Ottoman border was assessed at over 20,000 silver tangas — a huge sum. Luna: That's a lot of pie filling. Lucas: It is. But the real value was medicinal. And there's a darker side: the demand for rhubarb drove overharvesting in the wild. By the 18th century, the best wild rhubarb stands in Gansu and Kokonor were being depleted, and the Qing dynasty had to impose regulations on gathering. They designated certain mountains as protected areas, and only licensed collectors could harvest the root — a very early example of resource management driven by global trade. Luna: So the rhubarb trade actually led to conservation laws? Lucas: In a way, yes. The Qing government created a system of 'rhubarb inspectors' who would check the quality and weight of each shipment before it left the province. And they banned the export of live plants — that's why the VOC had such a hard time. So the Chinese managed to maintain a monopoly for centuries partly through natural advantage and partly through strict controls. Luna: Were there any attempts to smuggle live plants out? Lucas: Plenty. The most famous attempt was by the British naturalist Sir Joseph Banks in the late 1700s. He persuaded the East India Company to offer a reward for anyone who could bring back viable rhubarb seed from China. Several captains tried, but the seeds either failed to germinate or produced inferior plants. The breakthrough came only in the 1870s when a missionary named Father David — the same man who discovered the giant panda — sent back seeds of Rheum palmatum from the mountains of western Sichuan. Those seeds finally produced the true medicinal rhubarb in European gardens. Luna: So it took a panda priest to crack the rhubarb code. Lucas: Exactly right. Father Armand David — he was a French Lazarist missionary and an avid naturalist. In 1869, he sent a shipment of seeds to the Muséum National d'Histoire Naturelle in Paris, and from there they spread to botanical gardens across Europe. That single act essentially ended the Chinese monopoly on rhubarb cultivation, though the Chinese root still commanded a premium for many decades. Luna: It's amazing how one plant can tie together so many different stories — espionage, economics, medicine. Lucas: And that's what I love about trade history. You start with a root, and you end up talking about Qing inspectors, Dutch botanists, Mughal tax collectors, and a missionary in Sichuan. Every commodity has a web of human stories behind it. Rhubarb's just happens to be particularly... purgative. Luna: I walked right into that one. Lucas: Next time you see rhubarb at the market, just remember: you're looking at one of the most valuable trade goods in history, fought over by empires and guarded by monks. Luna: I'll never look at a pie the same way again. Lucas: Good. That's the goal. Thanks for listening, and we'll see you next time on Trade Routes That Changed Human History Forever.