The Big Picture: The greatest picture in the world

Work has begun to preserve The Resurrection, a 15th Century fresco by Piero della Francesca once described as "the greatest picture in the world" by novelist Aldous Huxley. Businessman Aldo Osti has donated half of the 200,000 euro (£160,000) needed to fund the two-year restoration project near Sansepolcro in central Italy.