In 2003 a collection of Medieval and Renaissance pottery was put on display in the castle at Ostia built in the second half of the fifteenth century by Cardinal Giuliano Della Rovere. The aim of this project was a greater use of the monument, including the opening to the public of some formerly closed rooms on the first floor of the Papal apartment and in the keep. The pottery on view, recovered in the course of 20th century excavations and restorations within the castle and the neighboring hamlet, includes both cookware (Red Band Ware, glazed cookware of the fifteenth-seventeenth century), and tableware (Monochrome Late Medieval Glaze, Maiolica Arcaica, Graffita, Renaissance Marmorizzata and Maiolica). The study of such materials has comprise a series of archeometric analyses on a large sample of Renaissance glaze typologies. These resulted in a more precise analysis of the technologies used and the methods of wear, and in particular a greater objectivity in the identification of the different productions, local and imported, on the basis of the petrographical analyses of the clays and surface treatments, and comparison with the major Italian production centers known from the bibliography. (Simona Pannuzi)