There is evidence that Shakespeare’s company, the King’s Men, performed the play for King James I in May 1613—and that Shakespeare and John Fletcher, his collaborator for Henry VIII and Two Noble Kinsmen, wrote it. But the play itself is nowhere to be found.
And what a shame! From the title, scholars infer that the plot had something to do with a scene in Miguel de Cervantes’ Don Quixote involving a character named Cardenio. (A translation of Don Quixote was published in 1612 and would have been available to Shakespeare.)
A lost book that I would love to read is an account by Pytheas of Marseilles, a Fourth Century BCE Greek explorer. He is thought to have explored Britain and the Baltic Sea long before other Greek explorers reached these areas. Alas, his manuscript survives only in quotation by other ancient authors.
Link -via Marginal Revolution | Photo: Wikimedia Commons
On second thought, that might be too painful.