It seems odd to enter a room dominated by what Aldous Huxley famously called ‘the greatest picture in the world’ to find not another soul there. Looking down from an end wall of the mediaeval civic hall in the quiet little Tuscan town of Borgo San Sepolcro, Piero della Francesca’s ‘Resurrection’ is an image of astonishing power, showing a stern-faced risen Christ stepping out of his tomb in the dawn light of the first Easter morning like an unstoppable force of nature, exuding supernatural authority as he turns the leaves on the trees behind him from wintry death to the...