 Verdi and Boito filleted The Merry Wives of Windsor and combined it with parts from Henry IV to flesh out the central character. They combined Shallow and Slender into Dr. Caius and transferred Anna slash Nanetta's parentage, eliminated Mr. Page, and so you only have two instead of three gullings of Falstaff. We lose his disguise as the old woman of Brainford. But a brilliant piece nonetheless.