Facts:
• Occurred in Europe from 1346 to 1353.
• 50 million people died = 50% of Europe
• Caused by the bacterium Yersinia pestis
• Spread by fleas and through the air.
• Probably came from the Black Sea area
There are many theories on why it appeared. After all, the pandemic was not the first one. The Plague of Justinian (541–549 CE, with recurrences until 750) was the plague. And there were indeed other occurrences.
The accepted wisdom )Wiki) is: “Plague was reportedly first introduced to Europe via Genoese traders from their port city of Kaffa in the Crimea in 1347. During a protracted siege of the city in 1345–1346, the Mongol Golden Horde army of Jani Beg—whose mainly Tatar troops were suffering from the disease—catapulted infected corpses over the city walls of Kaffa to infect the inhabitants, though it is also likely that infected rats travelled across the siege lines to spread the epidemic to the inhabitants.
As the disease took hold, Genoese traders fled across the Black Sea to Constantinople, where the disease first arrived in Europe in summer 1347.
However, there is a lot of speculation about all of this. Like, why did the rodents (rats!) move out of Asia, carrying the plague? One theory is climate change. The grass lands became dry so they moved on to cities and better pastures.
A fact is that the rodents also got to feed from the granaries (grain silos) and thereby shedding the fleas carrying the disease. The fleas could also feed on corn dust, so they survived a trip from the Black Sea to the Italian coastal cities.
But there is a catch: why would the merchants around the Black Sea ship grain to Italy and other cities along the Mediterranean Sea?
This is where I found a most interesting article here
It is rather speculative, but it does have a bid on why the importation of grain from Black Sea to Mediterranean took place.
quote: “The study authors believe an eruption occurred around 1345, about two years before the start of the pandemic, from either a single volcano or a cluster of volcanoes of unknown location, likely in the tropics.
The resulting haze from volcanic ash would have partially blocked sunlight across the Mediterranean region over multiple years, causing temperatures to drop and crops to fail” and “An ensuing grain shortage threatened to spark a famine or civil unrest, so Italian city-states, such as Venice and Genoa, resorted to emergency imports from the Black Sea region, which helped keep the population fed”.
This is the trigger of it all. A few sailors going home after the siege could not have caused such a massive outbreak. But an import of infected grains in the hundred of tons probably could.
Ice core samples confirm that there indeed was volcanic eruptions at the ‘correct’ time. That supports this theory.
But there is another ‘anomaly’: Why did some cities like Rome and Milan not have the plague? At least not to the same extent as Venice and genoa? What was the difference between them?
This is where it becomes captivating: Rome and Milan were both situated in crop-growing areas. There was no need to import grain, at least not by the ship-load. So maybe there were cities and regions that did not get impacted to the same degree as other areas?
It is a theory that explains the missing parts of the puzzle, most importantly the big WHY.
Let us just look at one thing: the plague spread along trade routes and it might very well have started with the increase in grain imports to Italy.
The map spells out that it was not a uniform spread of deaths. So Poland did not import grain, but they also had very strict quarantine regimes.
Maybe the siege of Kaffa was a part of it all, but not the entire explanation and cause of it all?
The article suggests that a volcanic eruption could have caused the why. First out, it sounds like something science-fiction. Something to do with space bats and aliens or something. But it is actually a well-founded theory.
It is a matter of tonnage. Grain import was far bigger than a few sailors going home.
Grain trade was established, but the famine occurred some 2 years prior to the plague arriving in Europe.
That might have been another link in the chain of events.
Did you know:
The word quarantine comes from the Italian sentence ‘quaranta giorni” which was 40 days of isolation for all who arrived in Venice during the Black Death.