Interlude: More Mongol Destruction

The Mongol Empire didn't just spread culture, art, and ideas. It also spread the Black Death. All these people going around, low sanitary standards... yeah, it was likely to happen.

They've traced the Black Death to rodents in Central Asia. It was spread through the trade routes that the Mongols protected as well as through maritime trade on the Mediterranean Sea. But it didn't reach Europe until the Mongols reached Kaffa.

Kaffa was a city in what is now the Crimea, in the Ukraine, on the coast of the Black Sea. The Mongols were besieging it, like they were wont to do, but their army was not doing well. They were infested with the plague. So what's a Mongol army to do in a pinch but innovate?

They catapulted the dead bodies of the afflicted over the walls of Kaffa.

Whether or not this story accounts for the spread of the disease in Europe (Kaffa was full of maritime traders, who would've sailed west after the Mongols gave up and the siege was over) is far from proved. I'm not sure that the dead bodies were even contagious. But dude, flinging the dead over to the other side in a primitive attempt at biological warfare? Genius.