Browning, Robert.
The pied piper of Hamelin. (London : Edward Moxon, 1842).
http://www.gutenberg.org/ebooks/16376.
Notes
"The poem is based on an old myth found in many forms, all turning upon the attempt to cheat a magician out of his promised reward. See Brewer's Reader's Handbook, Baring-Gould's Curious Myths of the Middle Ages, Grimm's Deutsche Sagen, and the Encyclopaedia Britannica. There are Persian and Chinese analogues."