«The Pied Piper of Hamelin is the subject of a legend concerning the departure or death of a great many children from the town of Hamelin (Hameln), Germany, in the Middle Ages. The earliest references describe a piper, dressed in pied (multicolored) clothing, leading the children away from the town never to return. In the 16th century the story was expanded into a full narrative, in which the piper is a rat-catcher hired by the town to lure rats away with his magic pipe. When the citizenry refuses to pay for this service, he retaliates by turning his magic on their children, leading them away as he had the rats. This version of the story spread as a fairy tale.
This version has also appeared in the writings of, among others, Johann Wolfgang von Goethe, the Brothers Grimm, Robert Browning and Megadeth.»
Source: Wikipedia