The Changeling is a play about passion, deception, and the grotesque. It features a number of ill-intentioned characters who let their sexual and financial appetites govern their moral decisions. At a time when early modern English plays usually had straightforward titles – especially tragedies – The Changeling stands out among its contemporaries for its unique and somewhat enigmatic title of the performance.
At first glance, it would appear that the play's title has little to do with its subject matter. After all, the concept of a "changeling" was an ancient one based on English folklore. In this tradition, a changeling was a child given to human parents after their true child was stolen by fairies. The changeling child was meant to distract and fulfill the parents while the fairies raised the human child as their own.
Of course, there are no such fairies or children in The Changeling. However, over time, the concept of a changeling evolved to denote any kind of substitution of one thing for another. As such, stories of changelings typically involve major themes like deception, disguise, and general trickery. In this play in particular, one could argue that Diaphanta is used as a changeling for Beatrice-Joanna, who convinces her maid to have sex with her husband so that he will not discover she is not a virgin. More generally, the play interrogates the notion of substitution and deception through these various changeling plots (the disguises of the madhouse could also be viewed in this particular light), asking the audience to question the extent to which the characters can trust what they see.
