The 400-year-old mystery of whether William Shakespeare was the author of an unattributed play about Edward III may have been solved by a computer program designed to detect plagiarism.

Sir Brian Vickers, an authority on Shakespeare at the Institute of English Studies at the University of London, believes that a comparison of phrases used in The Reign of King Edward III with Shakespeare’s early works proves conclusively that the Bard wrote the play in collaboration with Thomas Kyd, one of the most popular playwrights of his day.

The professor used software called Pl@giarism, developed by the University of Maastricht to detect cheating students, to compare language used in Edward III — published anonymously in 1596, when Shakespeare was 32 — with other plays of the period.

He discovered that playwrights often use the same patterns of speech, meaning that they have a linguistic fingerprint. The program identifies phrases of three words or more in an author’s known work and searches for them in unattributed plays. In tests where authors are known to be different, there are up to 20 matches because some phrases are in common usage. When Edward III was tested against Shakespeare’s works published before 1596 there were 200 matches.

Sir Brian said: “There might be ten to 20 common phrases between two plays by different authors. The computer is picking out three-word sequences that could just be chunks of grammar. But when you get metaphors or unusual parts of speech, it is different.”

The Shakespeare matches came from four scenes, about 40 per cent of the play. The remaining scenes had about 200 matches with works by Kyd, best known for The Spanish Tragedy, a play known to have influenced Shakespeare, indicating that he wrote the other 60 per cent of the play.

The suggestion that Shakespeare had a hand in Edward III has been debated for about 150 years but has found favour only recently. It was ignored by mainstream publications until 1997, when it was included in The Riverside Shakespeare, and has subsequently been accepted by The Oxford Shakespeare: The Complete Works.

Sir Brian said: “When you have 200 [matches] you can be pretty sure. Everyone can see that certain scenes are very Shakespearean, but no one could see why there were verses that are definitely not his. There is a real difference in quality between the two authors.”

The mystery has endured because some academics refuse to believe that Shakespeare collaborated with other playwrights at that stage of his career, he said. “They think, Shakespeare has been elevated to the position of the Bard, so why would he have collaborated with anyone else?”

Stanley Wells, chairman of the Shakespeare Birthplace Trust, said: “I am sceptical, frankly, that we have yet reached a stage where these computer-assisted investigations can prove authorship. It is difficult to judge the results without doing the research oneself. [But] it is part of the willingness to see Shakespeare not as an eminence, not as a person topping everyone else, but to see Shakespeare as a working dramatist collaborating with everyone else. He is one among many, rather than a god-like figure on his own.”

Jonathan Bate, Professor of Shakespeare and Renaissance Literature at the University of Warwick, said: “I think it creates a more realistic image of Shakespeare than perhaps the romantic view some have of him as a solitary genius.”

www.britac.ac.uk/literatureweek

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