The Comedy of Errors, always loved on the stage, has long been deemed less substantial than Shakespeare's ‘mature’ works. Its references to private and public law have certainly been noted: a trial, a breached contract, a stand-off between monarchical and parliamentary powers. Yet the play's legal elements are more than historical curios within an otherwise light-hearted venture. The play is pervasively structured by an array of socio-legal dualisms: master–servant, husband–wife, native–alien, parent–child, monarch–parliament, buyer–seller. All confront fraught transitions from pre-modern to early modern forms. Those fundamentally legal relationships fuel character and action, even where no conventionally legal norm or procedure is at issue. ‘Errors’ in the play serve constantly to highlight unstable and shifting relationships of dominance and submission. Law undergoes its own transition from feudal–aristocratic to commercial forms. Through a theatrical framing device, it thereby re-emerges to remind us that those dualisms, even in their new incarnations, will remain squarely within law's ambit.