Was the most famous poet and writer of all time a fraud and a plagiarist? Was Shakespeare the 'upstart crow' described by Greene as strutting in borrowed feathers, or Jonson's 'Poet-Ape' who patched plays together from others' work? Was his name merely a pseudonym for a well-known contemporary figure?

These questions have been furiously debated ever since the eighteenth century, when the writing styles of Marlowe and other playwrights were discerned in plays such as Titus Andronicus. The orthodox view is that the author of the works of Shakespeare was, of course, the actor and businessman of Stratford-upon-Avon.

But the known facts about this man are surprisingly meagre, and contrast puzzlingly with the learned, courtly philosopher revealed in the Sonnets and plays - the universal genius and supreme stylist.

Respected scholars and obsessive eccentrics have devoted years to the search for evidence, and many different theories have been put forward. Some believe that the great lawyer Francis Bacon may have used the name of an obscure actor to disseminate his philosophy. Many others, including Freud, see the Earl of Oxford mirrored in Hamlet. Yet others suggest that Marlowe was not killed, as thought, in a drunken brawl, nor even in a secret service execution, but lived on to write secretly as Shakespeare.

John Michell's enthralling investigation of the many claims and counter-claims reads like a series of detective stories. He lays out the evidence and the arguments for the various candidates, not forgetting Shakespeare himself, and provides a drily humorous commentary on the research and prejudices of their champions while adding new insights of his own. By the end of the book, even the most faithful disciples of the Bard will find themselves questioning 'Who Wrote Shakespeare?'.