Why Killing Cats Caused the World’s Deadliest Plague

Added: 2026-05-21

[00:00:00]Did you know a pope once ordered a mass killing of cats and it might have helped cause the Black Death?

[00:00:06]In the 1200s, Pope Gregory the IX believed black cats were evil.

[00:00:11]He actually thought they were servants of Satan.

[00:00:14]So, in 1233, he issued a crazy order, kill the cats.

[00:00:19]And people across Europe obeyed.

[00:00:22]Thousands of cats, especially black ones, were tortured and wiped out. But here's where it backfires. With fewer cats around, rats exploded in numbers and those rats carried the bubonic plague.

[00:00:37]Historians say this may have made the Black Death even worse, killing up to 200 million people.

[00:00:44]So, yeah, one people order to kill cats might have accidentally helped trigger one of history's deadliest pandemics.

[00:00:52]Moral of the story? Don't mess with cats.