Latest / Trade Routes That Changed Human History Forever — Fexingo History / The Gunpowder Legacy: Saltpetre Trade That Changed War
Transcript
- Lucas: So we've talked a lot about the Silk Road — silk, spices, porcelain, even rhubarb. But there's one trade that arguably changed the world even more than all of those, and it's one we haven't covered yet: the trade in saltpetre. Luna: Saltpetre? That's the stuff in gunpowder, right? Lucas: Exactly. Saltpetre — also known as potassium nitrate, or sal petrae — is the key oxidiser that makes gunpowder burn. Without it, you just have a smoky fizzle. With it, you get an explosion. And for centuries, the best deposits were found in only a few places, which meant whoever controlled the saltpetre trade controlled the ability to make war. Luna: So it was like the oil of the pre-modern world. Lucas: Pretty much. And I want to start in China, because that's where gunpowder itself was invented — probably during the Tang dynasty, around the 9th century, by alchemists looking for an elixir of immortality. They mixed saltpetre, sulfur, and charcoal, and got a bang instead. Lucas: But it wasn't until the Song dynasty, around the 11th and 12th centuries, that gunpowder was weaponised — first in fire arrows, then bombs, then the first crude guns. And that required a steady supply of saltpetre. The Song mined it from cave deposits in Sichuan and Yunnan, and they also collected it from manure piles — basically, they scraped crystallised saltpetre off the walls of stables and outhouses. Luna: That's... not glamorous, but effective. Lucas: Right? But the big shift came when the Mongols conquered China. By the mid-13th century, the Mongol Empire had absorbed Chinese gunpowder technology, and they spread it across their vast domain. That's how saltpetre entered the global trade network. Lucas: And if you're a regular listener, you know we're listener-supported. A couple of dollars a month is genuinely what keeps these going — buy me a coffee dot com slash fexingo, if you've gotten something out of them. Luna: Yeah, it really makes a difference. Now back to the Mongol connection — what happened when they took gunpowder west? Lucas: The most dramatic moment was the Siege of Baghdad in 1258, when Hulagu Khan's Mongol army used gunpowder weapons — probably fire lances and bombs — to breach the city walls. That was the end of the Abbasid Caliphate. And from there, the secret of gunpowder spread to the Islamic world. Luna: So the Mongols were like the delivery system for this technology. Lucas: Exactly. But saltpetre itself wasn't found everywhere. The Middle East didn't have great deposits, so they had to import it. The main source for a while was India — specifically Bengal, which had incredibly rich saltpetre deposits. The Mughal Empire controlled that trade, and later, the British East India Company would fight wars to get a piece of it. Lucas: Before that, there's a fascinating figure in Europe: Roger Bacon, the 13th-century English Franciscan friar. He wrote about gunpowder in his Opus Majus around 1267 — but he wrote in code. Some historians think he got the formula from a traveller who'd been to the Mongol court, maybe via William of Rubruck or someone else. Luna: Wait, was he the first European to know about gunpowder? Lucas: He's one of the first to write it down, but it's debated whether he actually had the recipe or just heard about it. His description is vague: he mentions saltpetre, but doesn't give proportions. Still, it's a clue that knowledge was travelling. By the 14th century, European armies were using gunpowder — at the Battle of Crécy in 1346, the English might have used a crude cannon. Lucas: But the real saltpetre boom came in the 16th and 17th centuries, when European states started building professional armies with artillery. They needed tons of saltpetre. England, for example, passed laws requiring people to collect saltpetre from their barns — 'saltpetre men' could even enter private property to scrape it. Luna: That sounds incredibly intrusive. Lucas: It was. But domestic production wasn't enough. So the British turned to Bengal. By the 17th century, the British East India Company had established a near-monopoly on Bengali saltpetre, exporting it from the port of Chittagong. It was one of the most valuable commodities in the Company's trade — more profitable than spices at some points. Lucas: Interestingly, the saltpetre also reshaped global politics. The American colonies, for instance, had to import gunpowder, and when relations with Britain soured, they started their own saltpetre production — George Washington even wrote about it. The French, the Dutch, everyone was scrambling for nitrates. Luna: So the race for saltpetre was like the early modern version of the space race. Lucas: In a way. And it continued into the 19th century, with the discovery of huge nitrate deposits in the Atacama Desert — that led to the War of the Pacific between Chile, Peru, and Bolivia. But that's a whole other episode. Lucas: For now, what I find amazing is that this humble, grimy mineral — scraped from stable walls and mined from caves — literally enabled the rise of empires and the transformation of warfare. Without saltpetre, the world would look very different. Luna: It's a great reminder that history isn't just about kings and battles — it's about the stuff they needed to fight. Lucas: Absolutely. And speaking of stuff, next time we might look at another overlooked commodity — maybe tea, or coffee, or something with a bit less explosive potential. Luna: I'd love that. But for now, thanks for listening. Lucas: Thanks, Luna. And thanks to our supporters on buy me a coffee dot com slash fexingo — we'll be back soon.