Does "The Pied Piper of Hamlin" Describe a Real Event?

I have read that this famous story is actually founded upon a real event-the migration of young people from Germany to Transylvania (now Rumania), in the 13th century.
Is this true?
I was reading about the Transylvanian Germans (who are almost extinct)-they are a fascinating group-as they never assimilated (they kept their language and customs intact).
Anyone know a good source on this?

There’s no definitive answer to this, last I heard.

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