Cardenio, a “lost” play of 1612-13 based on Shelton's translation of Don Quixote (1612), is partly preserved, in altered form, in Lewis Theobald's Double Falshood of 1727. Theobald probably altered Cardenio drastically, as he did Richard II. To internal evidence that Cardenio was written by Shakespeare and Fletcher can be added chronological evidence and reluctant testimony to the joint authorship by the publisher Moseley, Charles Gildon, and Theobald. One of Theobald's three manuscripts can be traced in the hands of Moseley, the Davenants, Betterton, Gildon, Theobald's patron (Charles Boyle), and Theobald. A Restoration performance probably was intended. Theobald persisted in claiming that the original play was by Shakespeare alone after he learned otherwise, from Gildon and the Stationers' Register, to save his reputation as a Shakespeare scholar and please his patron. To protect his “Shakespeare” play, Theobald obtained a unique royal license, which Pope ridiculed in the Dunciad. Theobald probably sold his play and Shakespeare manuscripts outright to his publisher. He was prevented from publishing Cardenio by the copyright Act of 1710, the practice of regarding copyright as perpetual, and his quest of money and patronage.