In addition to the roundels with Saint Bonaventure and Saint Louis, the Basilica  dell’Osservanza is house to another two marvellous masterpieces by Andrea della Robbia (1435 – 1525). He came from a  famous family of sculptures, specialised in the manufacture of glazed polychrome terracotta creations, a technique invented around 1440 by Luca della Robbia. This process, which entails the . . .