The 132 drawings catalogued document most of the major examples of ancient Roman pictorial art known to seventeenth-century Rome. They include early finding such as the Aldobrandini Wedding, the Nile mosaic from Palestrina, tha marble pictures from the Basilica of Junius Bassus, and later finds such as the Harbour Landscape (found in 1668) and the Tomb of Nasonii (1674). Detailed accounts are given of the discoveries, and a general introduction assesses the significance of the Cassiano assemblage within the wider context of contemporary antiquarian interest in ancient painting, its collectors and copyists. Cataogue entries describe and discuss the drawings in graet detail, relating them to the original mosaics and wallpaintings as they survive in their present state of preservation. All drawings catalogued are reproduced, mostly on a large scale and mostly in full colour. They are frequently accompanied by illustrations, also in colour, of the ancient originals.