Witches and fairies were supposed to be given to stealing beautiful and promising children, and substituting their own ugly and mischievous offspring. Shakespeare alludes to these "changelings," as they were called, in the Midsummer-Night's Dream (ii. 1. 23), where Puck says that Oberon is angry with Titania
"Because that she as her attendant hath
A lovely boy, stolen from an Indian king;
She never had so sweet a changeling."
This "changeling boy" is alluded to several times afterwards in the play.
In the Winter's Tale (iii. 3. 122), when the Shepherd finds Perdita, he says: "It was told me I should be rich by the fairies; this is some changeling"; and the money left with the infant he believes to be "fairy gold." As the child is beautiful he does not take it to be one of the ugly elves left in exchange for a stolen babe, but a human changeling which the fairy thieves have for some reason abandoned. If it were not for the gold left with it, he might suppose that the stolen infant had been temporarily hidden there. We have an allusion to such behavior on the part of the fairies in Spenser's Faerie Queene (i. 10. 65):—
"For well I wote thou springst from ancient race
Of Saxon kinges, that have with mightie hand,
And many bloody battailes fought in face,
High reard their royall throne in Britans land,