Unexplainable

A better Black Death story

32 min
May 13, 202621 days ago
Listen to Episode
Summary

This episode reexamines the popular narrative of how the Black Death reached Europe in 1347, challenging the widely-told story of Mongols catapulting plague-infected bodies into the Italian port city of Kaffa. Through interviews with medieval historian Hannah Barker and climate researchers, the episode explores how small historical details and evidentiary gaps shape our understanding of major historical events, and how new research suggests grain shipments—not biological warfare—may have introduced the plague to Europe.

Insights
  • Historical narratives about major events often rely on single sources far removed from the actual events, requiring rigorous verification through multiple contemporary documents and evidence
  • The shift from intentional blame narratives to accidental transmission stories fundamentally changes how we understand historical causation and responsibility
  • Interdisciplinary research (climate science, genetics, medieval history) reveals previously hidden connections and mechanisms in historical events
  • Uncertainty and caveats in historical research are features, not bugs—they indicate scholarly rigor and invite deeper investigation rather than false certainty
  • Small evidentiary details (grain embargoes, climate patterns, flea biology) can completely reframe major historical explanations without changing core facts
Trends
Increasing use of DNA analysis and genetic sequencing to verify historical claims about disease origins and transmissionShift toward interdisciplinary historical research combining climate science, biology, and documentary analysisGrowing recognition of Eurocentrism in historical plague research and efforts to expand geographic scope of medieval disease studiesScholarly emphasis on distinguishing between intentional historical narratives and evidence-based reconstruction of eventsClimate and environmental factors being integrated into explanations of historical pandemics and trade patternsMethodological rigor in source criticism, including geographic verification of historical authors through document dating and location records
People
Hannah Barker
Challenged the catapult narrative and proposed grain shipments as plague vector to Italy
Ulf Böntgen
Co-authored paper on climate and Mediterranean grain trade connections to Black Death
Martin Bauch
Co-authored paper examining climate patterns preceding 1347 plague arrival in Europe
Gabriele de Mussi
Author of primary source account of plague, but located in Piacenza, not Kaffa during siege
Bird Pinkerton
Host and producer of the Unexplainable podcast episode
Noam Hassenfeld
Composer of music for Unexplainable podcast
Brian Resnick
Co-creator of the Unexplainable podcast
Quotes
"We have to be honest and always cautious. This is something that happened 700 years ago."
Ulf Böntgen or Martin BauchEarly in episode
"Rather than looking for who to blame, thinking about how this can happen in a way where no one meant for it to happen."
Hannah BarkerMid-episode discussion
"The first story is like someone did this to Europe and there's someone to blame. And the second story is just, you know, the way life works, that things travel and disease travels and sometimes it happens."
Bird PinkertonNarrative comparison section
"It's hard to tell a story about the past where something terrible happened and there isn't a bad guy."
Bird PinkertonReflection on storytelling
"Once you open a new door like this paper does, saying, you know, maybe it was grain, not biological warfare, that then invites people to walk through that door."
Bird PinkertonClosing discussion
Full Transcript
When you run a business, you want the right tools. Enter Shopify. Shopify is the commerce platform behind millions of businesses around the world, from household names to brands just getting started. With hundreds of ready-to-use templates, Shopify helps you build a beautiful online store to match your brand's style. So if you're ready to sell, you're ready for Shopify. Turn your big business idea into... with Shopify on your side. Sign up for your one euro per month trial and start selling today at Shopify.nl. Go to Shopify.nl. That's Shopify.nl. Power your business with the platform trusted by millions today. What's up, y'all? I'm Skylar Diggins, seven-time WNBA All-Star, Olympic gold medalist, and mom. And I'm Cassidy Hubbard, host and reporter for nearly 20 years, covering the biggest names and stories in sports. And mom. And this is And Mom, a community for athletes, game changers, and moms of all kinds. Dropping May 14th. Tap in with us. Noam, are you ready? Yes. Hello. Hi. Hello. I have you here today to talk about the Black Death. Fun! Yeah. Well. Wow. Kind of, actually, though. Like, interesting. at least. You had a fun take on the Black Death? Well, I got interested in the Black Death because this paper came out last year about sort of climate and the Black Death in Europe. And I wound up calling up these two lovely researchers, this guy named Ulf Bündchen and another guy named Martin Bauch. And I wanted to talk to them about their research. And I was doing the thing that we usually do, which is to basically be like, let's establish a baseline of information here. Like, let's just get our facts straight before we dive into the research. But then as I was asking sort of, what's the Black Death? Like, what are the basics here? They would sort of hit me with these caveats. We have to be honest and always cautious. This is something that happened 700 years ago. So the idea that you're saying is that we don't know what the Black Death is? So no, we do know a lot. We know there was an outbreak of disease in the 1300s. We know this was one of the biggest pandemics in recorded history. We know it had a huge effect. So historians have made the case that this caused a lot of economic upheaval, spiritual upheaval. People have talked about it having an evolutionary effect on the people who survived it because there might have been genes that helped people survive that were then passed on. Or even people have made the argument that the Black Death laid the groundwork for some public health interventions that we know today. But like, as Ulf and Martin would talk to me about specific details that I honestly would have thought would be simple, They'd often hedge. Caveat? What exactly is he caveating? So a whole range of things. But one example would be how many people died. Because obviously people weren't doing statistics in the 1300s the way that we are now. But we know it was a lot, right? Yeah, we know. So the estimates that I encountered for Europe, at least, were initially I was hearing maybe like 30 to 50 percent of everyone died. But then some people are saying it was more like 40 to 60 percent of everyone died, which is a pretty staggering percentage. Yeah, I mean, COVID was nowhere near that. Right. So any of those estimates is sort of unimaginable. Yeah. But given how big a deal it was, I guess it surprised me that we don't have a better or narrower number on what percentage of people died or how many died. Mm-hmm. And I was sort of encountering that over and over. And so that's the show today. Instead of talking about climate and the Black Death, I wound up reaching out to a medieval historian named Hannah Barker. And she really helped me understand, first, like, why this key moment in our history is so hard to pin down. But also sort of why that ends up mattering, not to be too dramatic, but why it ends up mattering for how we tell our own history. A better Black Death story. A better Black Death story. Actually, maybe. By the end of this. So, just to start, what do you know, just off the dome, about sort of what caused the Black Death? My mind immediately goes to rats. Mm-hmm. I feel like it was something like rats coming from somewhere in Asia on merchant boats or something. And then the boats come to some port in Europe, like Italy or something. And then the people on the boats get infected or the rats go off the boats and infect people. But long story short, rats is my answer. Got it. And what are they giving people in your mind? Like, what's the disease beyond just like the Black Death? Bubonic plague? Okay, so yes. This is basically exactly what I learned in school as well, right? There were rats, they were spreading the plague. This explanation goes back a long time. But for decades now, researchers have been kind of reexamining that sort of textbook basic understanding here and trying not to make assumptions. So, for example, even the most basic thing, the idea that this is plague, until as recently as the 2010s, that was being debated. Seriously? Yeah, like to me, black death and plague are inextricably linked, right? Black death is plague. But that was actually an open question. The disease that we nowadays call plague is caused by this bacterium, Yersinia pestis. Yersinia pestis. Yersinia pestis. It can have different forms if the bacteria gets into your lungs or your blood or your lymphatic system. And the version you and I had heard of, bubonic plague, is when it swells up your lymph nodes into these large buboes that can be the size of an egg. It's also pretty grim if it gets into your blood and your lungs as well. And the plague symptoms that we know of nowadays, they sound like the things medieval authors were writing that they'd experienced. but some researchers had questions because they were like well in other instances of plague it hasn't spread this fast and with these descriptions medieval authors are they're just working in like a really different model of disease so they're talking about like the four humors or whatever this was like miasma theory time too right where right right disease is disease is kind of like a cloud of I don know smelling odorous vapor Right. And so some historians were like, given that it's a little apples to oranges and comparing these, are we sure they're talking about plague? How do we know about anything about bacteria in the 14th century? What if it was a different disease? So there was a lot of debate about that. And ultimately, that wasn't resolved until they took a bunch of old bodies from Black Death mass graves and looked in their bones and their teeth and analyzed the DNA in them. And so they were able to collect teeth from the cemetery in London and test the teeth. And they found a lot of Yersinia pestis. And so that was kind of the convincing evidence that this is a plague outbreak. It is not other diseases. it is specifically plaque. So like, that is the level of kind of questioning everything that we are talking about here. And also sort of the level of proof you need for people to agree on things. You need like a smoking bacterium in a bone or a tooth. And in some other areas, we just don't quite have that level of clarity. So you mentioned rats, right? Rats. And the story I heard, very similar to the story that you heard, right, is like, okay, this bacterium, Yersinia pestis, right, it's in rats. The rats have fleas. Oh, the fleas. I totally forgot the fleas. Yeah. That's my bad. I'm sorry, rats. I blamed you. Well, I mean, the rats are also, they play a role. Yeah, but they don't want the fleas. I should have blamed the fleas. I'm sorry. Blame the fleas. And then we blame Eve. And then we blame the snake. And honestly, like, Adam's the one who ate that. Whatever. So the rats have fleas. Fleas bite the rats. And then the fleas move on to humans. They bite the humans. They give them plague. Got it. Yeah. That's already hard as a historian to sort of keep track of. Because, like, it's not just, like, what historical humans were doing. You had to keep track of what historical fleas were doing or, like, what historical rats were doing. And Hannah was like, we don't have rat histories to look at. Did fleas keep any records? You'll be shocked to learn fleas are illiterate. But the thing is that there's also now research that suggests that this is not just a story about rats. We can be looking at other kinds of rodents. We can look at other kinds of mammals. Camels, it turns out, are pretty good plague transmitters. Camels? Sheep, potentially, as well. And the same thing, it seems, is true with the insects. So there's this particular species of flea that is associated with the rats. That is kind of the go-to explanation. But there are other types of fleas, possibly also lice. On the biological side, this is one of the areas of investigation, is what other insects, what other rodents or mammals are potential carriers of the disease. Wait, wait, wait, wait. Camels? That is something that I would never have assumed camels were part of this. Right. And so as you can imagine, I went into this thinking, you know, we all know that it is about the rats. And then it was like, well, you know, and it sort of, it felt like over and over. There's more animals to blame. And don't forget the marmots. There are like lots of things about marmots as well. And they do sort of need to know which animals to pay attention to here because it is part of this sort of bigger project to figure out where did the Black Death even come from? Like, how did it get from point A to Z? And that's also more complicated than it might appear. So you mentioned when we first started this, Asia. And there have been attempts to use sort of genetics of Yersinia pestis to nail down an origin point. So basically to look at this bacteria and like its family tree and be like, can we trace things back and figure out where it might have started? And so you have papers pointing to different spots in Asia, but people sort of debate that. I gotta say, if we are still debating, like, where COVID started from six years ago, it's hard for me to imagine that we could figure out where the Black Plague started, like... 600-plus years ago? Yeah. Yeah, yeah. And then, like, from there, they're also debating sort of how did it move around? How long it took and what routes it took to move into the Middle East, into the area that's now southern Russia, the steppe, and then into Europe. That is an open question right now. That's an area of current research. And you might think, okay, bird, this seems granular. Okay, who cares if it's rats or camels? Like, who cares if it's from one place or another place? But one of the other things I realized in talking to Hannah was how a few facts kind of in one direction or another direction kind of changes our perception of things. In what way? After the break, I will tell you. Camels. that looks a certain way with my favorite pair of jeans. And what I really appreciated about Quince is that they had a whole range of different shirts for me to choose from. I wound up getting three different ones, each with variations in neckline and sleeves and material. And they were all pretty much exactly what I was hoping for. Now, you might not be looking for several different kinds of hyper-specific black shirts, But Quince also has lots of wardrobe staples for spring for you to choose from. Think 100% European linen shorts and shirts from $34 that are lightweight, breathable and comfortable, but still look put together. You can refresh your wardrobe with Quince. Go to quince.com slash unexplainable for free shipping on your order and 365 day returns now available in Canada too. That is Q-U-I-N-C-E dot com slash unexplainable. to get free shipping and 365-day returns. quince.com slash unexplainable. I'm Midge First, two-time NWL champion, championship MVP, and forward for the U.S. Women's National Team. Before I went pro, I graduated from Harvard with a degree in psychology, which comes in handy more than you think. Any athlete pursuing greatness knows there's a certain mentality you have to have. What people don't know is what that costs. In my podcast, Confessions of an Elite Athlete, I sit down with the best athletes in the world and explore the psychology, mindset, and unseen battles on the path to greatness. So take a seat and learn from the Confessions of an Elite Athlete on YouTube or wherever you get your podcasts. Hey, I'm Matt Buchel, comedian, writer, and floating head you may or may not have seen on your FYP. And I'm starting a brand new podcast. Wait, don't swipe away. It's called That Sounds Like a Lot. I'm going to start by breaking down whatever insanity is happening in the world. And then I sit down with a comedian or actor or writer or honestly anyone who responds to my DM This is not the place to get the news but it is a place to feel a little bit better about it You can watch on YouTube or listen wherever you get your podcasts That Sounds Like a Lot part of the Vox Media Podcast Network Rats! We're rats! We're the rats! We pray at night, we stalk at night. We're the rats! So, Hannah Barker, this medieval historian, zoomed in on one piece of the Black Death puzzle. The small but pretty consequential jump that people believe this bacterium, Yersinia pestis, made back in 1347. Specific. So I think that in that year, 1347, the bacteria moved from the Black Sea into parts of Italy, and then from Italy, it spreads through Europe, hits different parts of Europe in a big way in the next few years. And basically, some people think this sort of moment was a key moment for the European experience of Black Death. And there's this very long-standing story that people have told to explain what happened here. So the story starts in a port city called Kaffa, located in modern-day Crimea on the coast of the Black Sea. Kaffa had lots of Italian merchants living in it, especially Genoese merchants. And in the 1340s, they were under siege because they were fighting with the Mongol army. It can be called the Golden Horde. It can be called the Jochit Khanate. But the Mongol state that controlled the land in that area, they were fighting each other. And the Mongol army experienced this disease. People started to get sick. And so the story that people believed, the explanation for how Black Death ended up moving from Asia to Europe, was that what they did was throw bodies, catapult bodies over the walls into this besieged city. And so the people inside the city started getting sick and they abandoned the city and fled, but they took the disease with them. And so when these ships that were fleeing the siege went back to Italy, the people on the ship spread the disease to Italy. And that's how the Black Death ended up in Italy. And from there, it went to the rest of Europe. That's the story that was prevalent. Okay, so that's not rats or fleas. That's people. Well, it's fleas coming off of people. Okay, okay. Yeah, it is. It's very— But the fleas aren't going to fly over the walls. Right. It's this very intentional, like, the Mongols get the plague. They deliberately give Italians in the city the plague. Italians bring the plague home, right? It's seen as this, like, early example of biological warfare. One article I read mentioned that, like, this story is literally in the Encyclopedia Britannica. Wow. But Hannah does not believe in it. Doesn't believe it happened? She does not believe that this is how plague got to Italy. So people still kind of put it. Well, she told me, even before she got involved, people had questions about this. So, for one thing, plague apparently does not spread very easily from dead bodies. Fleas in particular, they will leave the body when it's cold. So if there's fleas in the clothing, then these are recently dead people. So are you going to take someone, you know, they died, all right, stick them in the catapult. Like, really? And people also thought this didn't totally make sense from, like, a military history perspective. flinging bodies in this particular situation. I love it. Okay. But more than kind of catapulted cold corpses, the thing that bothered Hannah about this story was essentially the source. So it comes from a text by a guy named Gabriela de Mussi, and he lived through the Black Death and wrote about it. But he was not in the besieged town of Caffa. He was in a town called Piacenza, which is thousands of kilometers away. Like in Italy, not Crimea, I assume? Yeah, exactly. He never went to CAFA. And we know that because his job was as a notary. So he wrote legal documents. He was a lawyer, but he was doing part of the lawyer's job that is writing documents. He wasn't making arguments in court. So because he was writing all these documents, every document has a date on it, right? And a place. And so we know that he was in Piacenza throughout the 1340s. He didn't travel. He was there. I'll just pause to say, like, I do really love the detective work that historians do. Like, I love that she's like, I went through all the documents and I can prove that this person notarized them. So I know where he was or where he wasn't 600 years ago. He didn't like to travel. He stayed home. But so Hannah's established, right? This guy, DeMussi, is not left Piacenza. So his information about Piacenza is fantastic. His information about Caffa in the Black Sea is not, because that's thousands of miles away, and he wasn't personally there. So as a historian, I want to ask, can we do better? Can we find someone who was in Caffa in 1345, 1347, 1350, this period, who is not only at the right time, but also at the right place? And the answer is yes. — She did find. She found a lot of sources, a lot of people writing in and around Kaffa at the time, records from the Italians, from travelers, and so on. So she read through all this material, and she found this document, this petition, actually, written after the siege was ended. Mongols were sick, they ended the siege, they left. And after that happened, some of the Genoese people in the city of Kaffa wrote this document. — They're writing back to Genoa, asking for help. They ask for a new bishop to replace the one who died. They also say in this letter, We want to re-fortify the city because the Mongols left, because they are suffering from an endless plague of death. So there it is. For Hannah, this document pretty clearly shows this story about dead bodies being catapulted into Kapha during the siege and spreading Yersinia pestis can't hold up. The disease is not transmitted during the siege because this is a petition that was written after the siege and the disease hasn't been transmitted yet. So, like, the Mongols did not deliberately give everyone in the town the disease because they'd already left. Nobody in the town had the disease. This whole thing is just kind of Kaffa-esque. Oh, a lot of people died, Noam. Too soon. Yeah, it's only been 600 years, dude. Okay, but if the dead bodies, the dead catapulted bodies, right, did not bring plague into Kapha, then what did, right? And so Hannah thinks that the answer here might be grain. Oh. In the letter. They talk about the horrors of siege. And when medieval people talk about the horrors of siege, what they usually mean is starvation. So this is a situation where they've been besieged for a little while. They were definitely running short on food. They were very afraid of that. Now the siege has been lifted. They're going to start importing food, right? From the countryside around, this is a grain-producing region. There's lots of grain there. It just wasn't coming into the city because of the siege. So one of the first things they're going to do in order to relieve the horrors of the siege is bring food. into the city. What travels with grain? Rats and mice. What travels with the rats and mice? Fleas. So there's plenty of other situations, other evidence that we have more in modern times, of grain shipments with rats or mice or other rodents that are carrying plague. There are also other historical examples of plague traveling with grain And so Hannah thought But you know what if that how plague came to the city What if it was not a Mongol act of war, but instead just something the townspeople did to themselves accidentally in a time of peace? It definitely gives it a different feeling of this was brought here aggressively to hurt people. Right. It becomes this like poignant thing. They don't understand what we understand about bacteria and plague transmission. They're aware that there's a disease. They think they probably are likely to get it, but they don't connect food shipping with disease transmission. So as far as they're concerned, what do you do to protect the population? You want them to be well-fed. They're already suffering because of the siege. bring food into the city so people can be well-fed, they don't realize that that is what is going to bring the disease into the city. And then when Hannah looks at how plague could have traveled to Italy, she also thinks, based on some digging, that, you know, Venice, Genoa, they were not getting grain from the Black Sea region during the siege. They had an embargo. So as soon as the siege is lifted, the grain shipments start to move again. and you can trace the timing of plague outbreaks in connection with the arrival of the grain chips. And so her case is that it's not intentional, you know, it's just grain chipping that brought Yersinia pestis into Italy and then spread the plague through Europe. Yeah, I mean, I'm thinking about what you said before about these small historical details shaping how we tell a story. And when I think about the difference between, okay, the plague came from Asia through Mongols catapulting dead bodies purposefully into a city that causes the residents of that city to flee and bring the plague to Italy, versus another story of there was a war, the Mongols got sick, they went away. then there was peace, but the people were hungry and they got wheat and the wheat had rats with fleas and then the people got the plague. Like that's just a totally different story. The first story is like someone did this to Europe and there's someone to blame. And the second story is just, you know, the way life works, that things travel and disease travels and sometimes it happens. And it's much more of a tragic story than a story that is one that has blame as a part of it. Yeah. Hannah said something so similar to this. This is actually a really good exercise in thinking about historical events that happened without intentionality. So I think that's something that's really important for us to think about, right? Rather than looking for who to blame, thinking about how this can happen in a way where no one meant for it to happen. It's just so interesting because even when I told the story, like when you asked me to say, what's the one thing I know about the plague? And I'm like, blame the rats. It's hard to tell a story about the past where something terrible happened and there isn't a bad guy. And I think it made me sort of even more than I already did respect the desire for caveats as people do history, the sort of desire to question everything. You love a good caveat. I love a good caveat. Because I think it's not like Hannah's totally changed all the pieces of the story, right? Like we are still talking about the Black Sea. We're still talking about Italy. We're still talking about 1347. We're still talking even about rats, right? Like, it's not like she came in and said, I think this was camels, actually. But it was camels. But it was camels. But if even a couple of small tweaks could make this story look totally different, there could also be researchers with bigger tweaks. One of the researchers I spoke to wants us to reexamine the timeline of the plague. Researchers I spoke to also emphasized that historians have been really Eurocentric in their plague research so far. And so maybe as they expand the scope of their understanding of the medieval world, there are other changes to make to the stories we tell here. I think that's part of caveating and reconsidering. I don't know, an exciting part of this to me is that once you open a new door like this paper does, saying, you know, maybe it was grain, not biological warfare, that then invites people to walk through that door. So those researchers I talked to about the climate stuff, Martin and Ulf, the people who sort of kicked this whole conversation off, Martin was saying that he was inspired to look into the Black Death because of Hannah's paper. He studies past climates. And when he saw this grain paper, he was like, climates play a role in grain. Like, maybe there's a connection here. And so he and his co-author found, you know, Europe had had a bunch of really terrible climate years leading up to 1347. There was sort of widespread famine. And so maybe it's not just that the embargo was lifted on grain from the Black Sea, but also maybe that Europeans were really desperate for grain from the Black Sea. Yeah, so if you're changing one detail here, it's not just changing this one story. By thinking about how we tell these stories, we're getting better questions. And then hopefully we can get to that better Black Death story. Hopefully. If you would like to read more about the Black Death, we will link to Hannah's paper, Laying the Corpses to Rest, in our transcript. And we will also link to the paper that was written by Martin Bauch and Ulf Böntgen, the paper on climate and the Mediterranean grain trade and the Black Death. This episode was produced by me, Bird Pinkerton. It was edited by the wonderful Lissa Soap. Thanks also to Sally Helm for some initial feedback and structuring help. Christian Ayala did the mixing and the sound design. Melissa Hirsch checked the facts. Noam Hassenfeld does our music. Meredith Hodnot and Joanna Solitaroff are the fact that camels have three eyelids. Thanks always to Brian Resnick for co-creating the show with me and Noam. And a big thanks also to Monica Green and Spike Gibbs for taking the time to speak with me about the Black Death, as well as to Martin Bauch and Ulf Böntgen for just being careful science communicators. Really appreciate it. If you have thoughts about the Black Death or if you think there are other historical diseases that we should dig into, we are at unexplainable at Vox.com. If you would like to support the show and the journalism that Vox does, we would love it if you would become a member. It is very easy to do. Just go to Vox.com slash members and you will get access to all of Vox's journalism. But you will also know that you are supporting all of Vox's journalism. And for those of you who have emailed to let us know that you signed up because of Unexplainable, thank you. And thank you to those of you who have left us a nice review on your podcast platform or told someone in your life about the show. You are all excellent. Unexplainable is part of the Vox Media Podcast Network, and we will be back very soon with another episode about everything that we do not yet know. Thank you.