Jewish hat

Exactly.

And this decree led to various forms of identifying badges across Europe, but specifically in the Germanic regions, it popularized the enforcement of something called the Judenhut, or the Jewish hat.

What did the Judenhut actually look like?

It was a tall, conical hat, often with a knob or a point at the top.

Now, here is a crucial nuance.

The Judenhut wasn't entirely invented by the church as a punishment.

It actually originated as a traditional piece of headwear worn voluntarily by some Jewish men in the Islamic world and parts of Europe long before 1215.

It was culturally organic.