(Sullivan: The Gondoliers). Sop. Daughter of the Duke and Duchess of Plaza‐Toro, she was married as a baby to the infant heir to the throne of Barataria. He is thought to be one of the gondoliers, but is shown to be Luiz, the Duke's drummer‐boy, with whom (fortunately) Casilda is already in love. Created (1889) by Decima Moore.