The Six Swans is a German fairy tale collected by the Brothers Grimm.It is tale number 49. Andrew Lang included a variant in The Yellow Fairy Book.It is Aarne-Thompson type 451: the brothers who were turned into birds.Other tales of this type include The Magic Swan Geese, The Seven Ravens, The Twelve Wild Ducks, Udea and her Seven Brothers, The Wild Swans, and The Twelve Brothers.
http://en.wikipedia.org/wiki/The_Six_Swans
