Rylance, the artistic director of The Globe Theatre in London, called the book THE TRUTH WILL OUT: UNMASKING THE REAL SHAKESPEARE "pioneering" and was asked to write an introduction by authors Brenda James and WILLIAM RUBINSTEIN.
In the intriguing investigation, James and Rubinstein claim the Shakespeare moniker was used by his distant relative SIR HENRY NEVILLE, who was the real Bard behind classic plays like HAMLET and OTHELLO.
The authors insist the real Shakespeare was not educated or experienced enough to pen the plays he's famous for, while his cousin was a well-travelled and well-educated courtier, who once served as England's ambassador to France.
James and Rubinstein claim there are hidden codes in Shakespeare's work that lead to Neville - an idea thrills Rylance.
In the book's foreword, he writes, "As this book rightly suggests, if the plays had not been attributed to Shakespeare in 1623, he would be the last person you would imagine able to write such matter."
It isn't the first time the authenticity of Shakespeare has been challenged - scholars have claimed the real writer of his plays was perhaps Christopher Marlowe, FRANCIS BACON or the Earl of Oxford, EDWARD DE VERE.