The untold truth of the Black Death

The Black Death is a fascinating slice of the past, even if it is a little dark for the impressionable minds of young children. If you didn't learn much about it in elementary school, most of what you know about it comes from Monty Python. Sure, it was hilarious when the not-dead-yet guy didn't want to go on the cart, but the real thing was much, much darker.

What exactly happened to people?

How would you feel about going back in time to get away from first-world problems? Pretty good? Medical standards might change your mind. According to the World Health Organization, the plague commonly know as the Black Death killed around 50 million people.

The 14th-century plague we're talking about was bubonic plague, which inflames the lymph nodes as it multiplies, turning them first swollen "buboes" and then into open sores. That's in addition to fever, chills, fatigue, and vomiting. Ole J. Benedictow, a history professor at the University of Oslo (via History Today), estimates this medieval plague outbreak had about an 80 percent kill rate. The one consolation was that victims only lived for around three to five days after developing the first symptoms. Less consoling is the three- to five-day incubation period where a person is infected but asymptomatic, giving them plenty of time to spread it all around.

And just as death waited for victims, so did indignity. A contemporary chronicler from Florence wrote of the dead laid in a pit in the church graveyard, covered with a layer of earth, and then another layer of corpses. He likened it to "just as one makes lasagne with layers of pasta and cheese." Good imagery, bad ending.

The 14th-century Black Death wasn't the first

The devastating plague outbreak we now call the Black Death swept across Europe between 1346 and 1353. The years before are a little hazy, but we do know this wasn't the first time this happened. The first started in 542 A.D. during the reign of Justinian, and it lasted for at least 225 years.

Well, 542 is when came to Constantinople, at least. According to the Ancient History Encyclopedia, it had been lurking in the shadows of the empire for a while, and was traced from Egypt to northeast India and China, moving along the trade routes.

It was mostly bubonic plague, probably with a little septicemic and pneumonic plague mixed in. The devastation and sickness lasted for centuries because of a weird confluence of factors the Smithsonian says started in 536 with the eruptions of two volcanoes. The air was filled with debris from the eruptions and, according to LiveScience, it was made even worse when a piece of Halley's comet collided with Earth and kicked up more dust. The climate cooled, crops failed, and people were vulnerable. The planet became the perfect breeding ground for plague. The 14th century was bad, but the sixth might have been even worse.

No one is sure when or where it really started

Justinian's plague disappeared in 750, and according to the Ancient History Encyclopedia, there wasn't another large-scale pandemic recorded until the Black Death. It's not entirely clear where the 14th-century outbreak came from, but historians love to argue about it.

According to ThoughtCo, there are a couple theories. We know Europe had just been opened to eastern trade in 1346, and while there hadn't been any major outbreaks for centuries, there were pockets of plague. One was in Asia's Lake Issyk-Kul (pictured), where archaeologists have pinpointed a plague dating to 1338 and 1339. It's also been found in China throughout the 1320s. It was in Europe in 1347, and pilgrims, merchants and caravans, and soldiers carried it to Mecca and Britain in 1349.

One thing we do know is how it entered Europe: through the ports of Messina and Genoa. In October 1347, trade ships made port in Sicily, filled with lovely silks from the Far East and also with dying sailors. At the same time, a Tartar siege on a Genoese trading post ended because of Tartar plague. As a parting gift, they catapulted their dead into the city. By the time trade ships returned to Genoa in January 1348, most of their crews were dead or dying.

It may have been driven by climate change

The plague had another devastating consequence — it pretty much ruined the reputation of rats, in spite of the fact they've been found to be at least as smart as college students at some tasks. We condemn them as harboring plague and being what scientists call "generally icky," but according to research by the University of Oslo (via the Smithsonian), rats weren't responsible for keeping plague dormant before reintroducing it to humans. 

Researchers looked at pockets and outbreaks of plague during the Black Death. They found plague corresponded with climate fluctuations, even when it came to temporary lulls in the death tolls. Remember how large-scale climate change seemed to exacerbate the plague in the sixth century? The same factors could have been at work later. When the weather gets warmer and wetter, rat populations decline. That means plague-carrying fleas need to find other homes, and even though they would generally prefer rats, they're forced to migrate to domestic animals and ultimately to humans. As if we didn't have enough to worry about with modern-day climate change, now you'll be thinking about how you're becoming the last resort for plague-loving fleas. Good luck not getting itchy while thinking about it.

It spread to Norway when a ghost ship ran aground near Bergen

You know it's a strange world we live in when The Guardian actually has to run a story with the headline, "Don't worry — a ghost ship crewed by cannibal rats probably isn't about to hit the British Isles." Whether you laughed at the idea or laughed a little nervously, you probably remember hearing the viral stories that circulated in 2014. It turns out the idea isn't that far-fetched, because that's exactly how the plague spread to Norway.

Plague spread fairly slowly, and word reached Scandinavia before sickness did. According to Gizmodo, the northernmost reaches of Europe even thought they might escape the Black Death, until some time in late 1349 or early 1350. When a ship left England in 1349, it was heading north carrying a hefty cargo of wool and plague. Every single person on the ship succumbed, but the ship kept its course. It ran aground not far from Norway's Bergen harbor, dumping fleas and rats into the previously untouched country. It's unclear how many died — estimates suggest it was about a third of the country — but we do know it spread from Norway into Sweden and finally Russia. Not so funny now, is it?

It led to the world's first quarantine laws

We have a weird fascination with the post-apocalyptic today, but these folks were actually living through what must have seemed like the End Times. For many, it absolutely was. It's impossible to imagine being in a position of authority and needing to deal with the outbreak, and according to a piece published in the academic journal Clinical Infectious Diseases, one city's leaders developed a now-familiar way of dealing with plague: quarantine.

The idea of separating someone who's ill from the rest of the population dates back to the Old Testament, when lepers were condemned to a life of exile. But a formal sort of quarantine — and the word itself — goes back to the medieval port city of Ragusa, which today is Dubrovnik, Croatia. In 1377, the city's council passed a series of laws that included a month-long isolation period for newcomers to the city. Anyone who wasn't officially tasked with caring for those in isolation was forbidden from visiting them, or they'd need to serve out a 30-day stint there, too. The idea spread to other cities, and eventually the 30-day period (trentino) became 40 days (quarantino), though no one's sure why. It may have had something to do with the Biblical significance of 40 days or the Greek idea that contagious diseases needed 40 days to show symptoms. Raise your hand if you're thankful for antibiotics.

Doctors tried everything they could think of

It wasn't that long ago we thought having a uterus and drinking absinthe were causes of madness, so when scores of people started dying, the doctors trying to cure it were in hopelessly over their heads.

They tried all kinds of cures rooted in the most serious beliefs of the time. According to Rachel Hajar, MD, of Qatar's Heart Hospital, the Catholic Church's belief that God sent illness to punish the sinners of the world led to people trying to cure themselves by prayer, pilgrimage, and even self-harm. The flagellants whipped themselves to show how sorry they were, but it didn't help.

The medical community was still governed by the ancient Greek idea that illness was caused by an imbalance in the body's humors, so other cures were focused on trying to get everything back in harmony. Doctors tried blood-letting, lancing boils, burning herbs, and bathing in rosewater or vinegar. (No reports of singing lessons for harmony, though it probably wouldn't have worked.) There was even a belief that plague was caused by stiff air, so ringing bells and letting birds fly around was another practice. According to the BBC, doctors tried giving their patients drinks of vinegar, 10-year-old treacle, and minerals like mercury. Others tried rubbing things on the boils, like pigeon and snake parts, onions, or herbs. Sounds nutty to our modern selves, maybe, but those who stayed to treat their dying patients knew their own chances of survival were poor, and still did the best they could.

That terrifying plague doctor costume was carefully designed

In the 14th century, the plague doctors didn't have that infinitely creepy, bird-like mask we think of today, but they were around. According to Doctors Review, a huge number of doctors realized they were fighting a fight they couldn't win, so they high-tailed it out of town. Cities and municipalities hired in others — the plague doctors — to care for the dying. While some were complete frauds and others did it in hopes of swindling devastated families out of everything, they're one of the most iconic symbols of the Black Death.

The creepy costume wasn't designed until the 17th century, and it was the creation of the favorite physician of the Medici family and the French royal court. Charles de l'Orme created it in hopes of isolating himself from the plague his patients were carrying, so the entire head-to-toe thing had a waxy coating. Gloves, boots, and the leather hood were tied shut with leather strips, and the eyes were protected by glass domes. Finally, let's talk about that mask. The beak was filled with herbs (usually myrrh, camphor, mint, or cloves) in hopes they would filter the air. The French went a step further, and their herb-filled beaks would be set on fire to produce smoke they thought was even more cleansing.

Most of the time, it didn't work. The plague doctors who didn't die were both outcasts and the stuff of nightmares.

Plague pits are rarer than you think

Contrary to popular belief, the London Underground doesn't weave around in order to avoid plague pits. (It was a cost measure.) There are no records of construction crews uncovering human remains while digging the Underground, and most of the tunnels are 40 to 80 feet underground, much deeper than any plague pit would be. There are a few times the Underground went through cemeteries, but what about the plague pits peppered all over the country?

University of London historian Vanessa Harding (via the BBC) says that even when plague got really, really bad, most of the victims were still buried in cemeteries and other designated burial grounds. It makes sense, too. As she says, people needed "stability and comfort" during those dark times, and giving their loved ones a proper burial was part of that. Most stories of plague pits are legend and lore, and we even know who to blame for popularizing the idea: Daniel Defoe, who listed some fictional plague pits for his drama Journal of a Plague Year. Real plague pits — like the one in East Smithfield or the one at Lincolnshire's Thornton Abbey — are rare finds, but even those bodies weren't just dumped off the death cart. They were buried carefully, or, at least as carefully as they could be by people who were also dying.

It has a strange impact on overall population health

Sure, 50 million people died during the Black Death, but as the great philosopher Kanye noted, that-that-that that didn't kill us only made us stronger. When researchers from the University of South Carolina looked at the skeletons of those who had survived, they found that post-Black Death people were generally healthier and lived longer. People living to at least 70, for example, nearly tripled in the years after the pandemic. There were more people living even past 50, and it was a trend that seemed to continue for the next 200 years.

They aren't entirely sure why the trend is there, but there are a few suggestions. It might be as simple as improvements in diet and standards of living, but it might also be because the Black Death took away the weakest section of the population. According to anthropologists from the University at Albany (via LiveScience), the plague didn't kill everyone. When they looked at skeletons of those who had succumbed to the plague, they found the disease was much more likely to kill the weak, the elderly, and those who were already sick. The population rebounded to be even stronger and healthier after they were gone. Sorry, weak links.

The Black Death changed our genetics (a little)

Just in case you were feeling all safe and cozy there behind your computer, know that the plague is still around. It's still mostly the same, too. Researchers analyzed the powdery residue inside the teeth of plague victims of London's East Smithfield Cemetery and were able to map the entire genome of the bacteria that caused the Black Death (via LiveScience). When they compared that to the genome of modern plague, they found only slight differences.

Something else did change during the plague years, though, and it's us. Researchers from the Radboud University Nijmegen Medical Center (via LiveScience) found there's a difference in the genes of European and Roma peoples compared to those from India. About 20 genes seem to have evolved simultaneously in Europeans and in the Roma but not in India, where there was no major 14th-century plague outbreak. Several of the genes govern immune function, and one cluster specifically causes a major response to plague bacteria. That suggests the Black Death sped up human adaptation to help some of us survive. At least something's looking out for us.