When the Metropolitan Museum bought Duccio’s Madonna and Child last year for a reported $50 million, the painting was hailed as a masterpiece. Now James Beck, a leading art historian and Professor of Art History at Columbia University in New York, believes that the painting, which the Met dates to 1300, is not by Duccio at all. “It is a fake based upon indications found in works by or associated with Duccio. It is not even a good forgery.”