What's in a name? William Shapiro might be able to tell you – but you probably know him better as Shakespeare.

According to a new book by French academic Ghislain Muller, Shakespeare's grandfather was a Jewish immigrant from Bohemia. He claims Richard Shapiro settled in England sometime after 1515, but hid his religion, assuming the name Shakespeare. Jews were banned from England during the Tudor era and were only re-admitted under Cromwell, 40 years after Shakespeare's death. "If Shakespeare, or his father or grandfather had acknowledged they were Jewish, they would have been dispossessed of all of their lands, houses and goods and probably deported," said Mr Muller.

Richard's son, John, married Mary Arden, a Christian, but Mr Muller believes Shakespeare's art was influenced by his hidden heritage.

"Most of the ideas transmitted in Shakespeare's plays are directly linked to Jewish moral standards," he said. "The ideas were coming from his father."

Mr Muller's interest in Shakespeare's Jewish roots emerged following a staging of The Merchant of Venice, the only play to feature an overtly Jewish main character. He began to wonder how the play "could be interpreted in such opposite directions… displaying a Jewish Shylock as humane in the text, and as inhumane on stage?

"I came to the conclusion that there was some kind of mystery with Shakespeare, and I started to study his work."

He said that the portrayal of the moneylender Shylock – which many maintain was antisemitic – should be viewed in the context of Shakespeare's secret identity. "He could not risk being unmasked. Had he depicted a good and sympathetic Jew, he would have run the risk of this."

Mr Muller said allusions to Jewish culture could be found in many plays, including one about kashrut in King Lear: "What dost thou know me for? ... an eater of broken meats."