Italian architect. On the basis of a document of 1239, he was appointed by Frederick II, Emperor and King of Sicily as supervisor of all castles constructed in Sicily that time. Accordingly, scholars believe that Riccardo may have built a series of buildings (maybe designed or just directed on construction sites): the Augusta Castle, a nursery in San Cosmo, the Maniace Castle in Syracuse, the castle of Caltagirone (no longer existing), the castle of Milazzo, the castle of Lentini (no longer existing). In 1246, he was in Prato to work on the enlargement of the Castello dell'Imperatore, the seat of Frederick I (also known as Frederick Barbarossa), the predecessor of Frederick II. //