My understanding of this story's evolution:

(1) In 1282 a stranger entered the town of Hamelin/Hameln and left with a large proportion of the town's youth.

(2) In the 15th/16th centuries the story of this incident merged with the folktale of the Ratcatcher's Revenge.

Does anyone know any versions of the unpaid contractor/unpaid piper/ratcatcher's revenge story that are not associated with the Hameln incident ?

T.