The curators of an exhibition in Florence have this week unveiled what they claim is the only surviving sculpture by Leonardo da Vinci. It’s always been part of Leonardo’s legend that he made sculptures, including a giant horse, but not a single extant three-dimensional work by him had been identified.

The Virgin with the Laughing Child is the miraculous exception, according to the curators of the exhibition Verrocchio: Master of Leonardo, at Palazzo Strozzi, where it has just gone on display. It has an unambiguous label: Leonardo da Vinci. He is said to have created it around 1472, when he was 19 or 20 and a pupil of the Florentine artist Andrea del Verrocchio.