ACCORDING to one newspaper William Shakespeare is "the ultimate English literary icon".

But is he? By which I mean, is he English? This was the iconoclastic thought that overcame me as I wandered round Beyond Macbeth, a fascinating exhibition at the National Library in Edinburgh which explores connections between Scotland and the Bard of Stratford.

It is not, I hasten to add, a question that the exhibition's organisers have sought to answer. They are more concerned with displaying rare books and manuscripts collected by Shakespeare aficionados and scholar. This is understandable. Since Shakespeare's death, his authorship of the greatest plays ever written has been hotly contested, most recently in the movie Anonymous, in which Edward de Vere, 17th Earl of Oxford, is touted as a literary genius.

As Bill Bryson noted in his short biography of Shakespeare, the claimants are legion and, in several cases, certifiable. Indeed, one them was called Looney, which did not help his case, while others were called Silliman and Battey. In all, Bryson reckons that more than 50 alternatives to Shakespeare have been proposed, none of whom has convinced him of their authenticity. The name most often mentioned is that of Francis Bacon, whose cause was taken up with eccentric fanaticism by an American, Delia Bacon, in the early 19th century. Ms Bacon, who was not related to her illustrious namesake, was a crackpot but one whom several people, including Ralph Waldo Emerson and Thomas Carlyle, took seriously. In a book published in 1857 she advanced her theory but chose not to mention Francis Bacon, leaving the reader, as Bryson wrote, "to deduce that he was the person whom she had in mind as the author of Shakespeare's plays".

Though half-baked, Ms Bacon started a trend that shows no sign of letting up. Among those who have been considered as an alternative to Shakespeare is his fellow playwright Christopher Marlowe, who in many respects seems plausible. He, however, died in 1593, before virtually all of the plays we have long assumed to be by Shakespeare were written.

The reason why there is doubt over their authorship is the lack of knowledge we have about the Bard. We cannot, for example, be sure what he looked like nor do we know exactly how he spelled his name. In biographies of him, the few facts are padded out with copious circumstantial detail. His background appears to have been humble and the extent of his education is a matter of speculation. Those who insist he did not write the plays ascribed to him base their claim largely on his perceived lack of schooling. How could someone who in his work displays such a broad depth of knowledge and experience have acquired this without wealth and connections? "The presumption," concluded Bryson, referring to the bard deniers, "is that William Shakespeare of Stratford was, at best an amiable stooge, an actor who lent his name as cover for someone of greater talent, someone who could not, for one reason or another, be publicly identified as a playwright."

But who could that person have been? There is just one who might fit the bill, namely James I and VI of Scotland, the son of Mary, Queen of Scots. James was born in 1566 and died in 1625; Shakespeare, meanwhile, was born in 1564 and died in 1616. We know that James could write and was the author of several books. Moreover, he was the inspiration behind the Authorised Version of the Bible, the other great literary achievement of the age.

On top of which, it was during James's reign that Shakespeare's theatre company was awarded a royal patent and many of the greatest plays, including King Lear, Macbeth and Anthony and Cleopatra, were produced. Of course, as king, James could not be acknowledged as their author but he could guaranteee their performance, which he did often. Who knows, he may even have written plays clandestinely while in Scotland before he succeeded Elizabeth I. Is it so preposterous to suggest that he and Shakespeare were collaborators? That the son of a tragic queen rather than that of a leather worker could write so convincingly of "the slings and arrows of outrageous fortune"?