by Nicholas Hilliard and Isaac Oliver at the National Portrait Gallery
For the same sentimental reason that we carry around with us photos of loved ones, the wealthy Elizabethan - 400 years ago - might be wearing a small jewelled locket. Inside it, a tiny portrait painted in water colours. Two of these exquisite little pictures came up for auction earlier this year. Roy Strong bid over £60,000 of the tax-payers' money to acquire them for the National Portrait Gallery and, he believes, it was money well spent.