The action of the play revolves mostly around S. Antipholus, though calling him the protagonist is definitely arguable, as he seems to be acted upon more than he acts in this play. S. Antipholus is definitely out of sorts – fearing he’s enchanted, dreaming, or mad – for much of the play, but to his credit, he keeps his wits about him and is constantly trying to get out of Ephesus, rather than being conquered by it. Further, S. Antipholus is our central character insofar as we know the most about him. He has no less than six soliloquies and asides, while we have no such personal insight into his twin. As the Antipholuses (or Antipholi) are the center(s) of the action, and S. Antipholus is the more fleshed out of the two, he earns our vote for being the protagonist.