The polychromy of ancient white marble sculpture has for the last 20 years become a focus of international awareness; from academics and the general public alike. Research results are gathered from scientific examinations of the “white” marbles, which unit e museums and universities in ambitious, cross - disciplinary projects all over the world. Yet, the research into ancient sculptural polychromy struggles with being accepted as an integrated part of - and not just curious contribution to - archaeological studies. Finding a common theoretical and methodological ground in this rapidly expanding research remains largely uncharged territory. This thesis tackles a yet unexplored area within this research field: the polychromy of Roman white marble portraiture. In the thesis results from examinations of 15 portraits from the collections of the Ny Carlsberg Glyptotek are presented, analysed , reco nstructed and discussed in detail. The thesis seeks to merge the results from scientific examinations with the archaeological and art historical research tradition into ancient portraiture. By doing so it represents the first book-length contribution in English that engages with the many controversial issues of colour on sculptural marble form, and which seeks to establish polychromy research in general within a traditional archaeological research field.