Sometime in 1623, seven years after Shakespeare's death, the actors John Heminges and Henry Condell published Mr William Shakespeares Comedies, Histories, & Tragedies – what we now know as the First Folio. It was the literary event of the century, recording for all time the sound of Shakespeare's English and the sweep of his imagination: Elsinore, Egypt and the Forest of Arden; a balcony, a spotted handkerchief and a skull.

Yet despite this shrine to Shakespeare's memory, erected by those who knew him, sceptics have continued to doubt his authorship of the plays. He was, they insist, inadequately educated, insufficiently travelled, and didn't know how to spell his own name. A range of alternative candidates have come and gone over the centuries, including Anne Hathaway, the Jesuits, and more recently Edward de Vere, the 17th Earl of Oxford, the subject of Roland Emmerich's film Anonymous. As always, conspiracy is more fun than consensus, and the doubters have the internet on their side. Shakespeare has thus become the focus of a global conspiracy industry, joining company with reptilian elites, self-destructing lightbulbs and skeletons on the moon....