His personal research mainly lies in the field of ancient sculpture, including Roman provincial art and the sculpture collection at Wilton House, for which he is completing the history and catalogue. His past publications include, Statues in Roman Society: Representation and Response (Oxford, 2003); Roman Art (Oxford/Cambridge, 2004); and The Social History of Roman Art (Cambridge 2008). As Director of the Classical Art Research Centre he is responsible for the Beazley Archive and he oversees research on a range of subjects, including connections between Graeco-Roman art and the Buddhist sculpture of Gandhara.