A portrait of William Shakespeare thought to be the only picture made of him during his lifetime has been unveiled in Warwickshire.

The painting is on show at The Shakespeare Birthplace Trust, Stratford-upon-Avon, to celebrate the playwright's birthday on 23 April.

The trust said it was convinced the artwork, thought to date back to 1610, was an authentic portrait.

But some critics have gone on record to say the picture is not of Shakespeare.