An article in the Smithsonian Magazine gives an overview of a recent publication suggesting that a major source for some of Shakespeare’s plays were those of the now little remembered Thomas North. Those are apparently lost, and positing lost texts can be a dangerous “short cut” of course, but the evidence looks to be substantial for identifying North as a writer whose works were subsequently used by Shakespeare. On the basis of the report, this appears to be a credible argument, even if the case is not proven.
It has long been appreciated that Shakespeare and other dramatists of the period re-wrote plays by other writers, bringing their own greater skills to bear and thus creating their own enduring achievements. In this case it is the identification of North as potentially the author of major sources that is important.
Shakespearean studies have over the years generated all kinds of eccentric theories as to other people who “wrote” Shakespeare. This however is a much more realistic and credible identification of source material. It does not really detract from Shakespeare’s genius any more than does his use of Plutarch or Holinshead. It might help explain however how it was that in a busy life as an actor-manager and travelling between bases in London and Stratford on Avon in a short period of years one man could be so remarkably productive of great work. As C.S.Lewis commented writers then saw their creativity in how they told an established story rather than it being a new one.
The article, which includes references to recent publications about the theory, can be read at Did Shakespeare Base His Masterpieces on Works by an Obscure Elizabethan Playwright?