A collection of bronzes sculpted by Renaissance master Donatello has been moved for the first time from the Italian churches where he installed them 600 years ago so that they can be displayed at a ground-breaking exhibition in Florence

Three of the four pieces, a relief, a statue and two bronze doors, from Siena Cathedral and San Lorenzo baptistery in Florence, are also being restored to their former glory using techniques ranging from chiselling with porcupine needles to thermographing to discover structural weaknesses.