The papers gathered in this volume explore the economic and social roles of exchange systems in past societies from a variety of different perspectives. Based on a broad range of individual case studies, the authors tackle problems surrounding the identification of (pre-monetary) currencies in the archaeological record. These concern the part played by weight measurement systems in their development, the changing role of objects as they shift between different spheres of exchange, e.g. from gifts to commodities, as well as wider issues regarding the role of exchange networks as agents of social and economic change. Among the specific questions the papers address is what happens when new objects of value are introduced into a system, or when existing objects go out of use, as well as how exchange systems react to events such as crises or the emergence of new polities and social constellations. One theme that unites most of the papers is the tension between what is introduced from the outside and changes that are driven by social transformations within a given group.