When reconstructing the past, the archaeologist needs to take into account all kinds of relevant information. Where no written evidence is available, the natural sciences play an indispensable role. Troia is a remarkable site in this respect. The present Troia project, under the directorship of Manfred Korfmann, integrates various disciplines including geoarchaeology, archaeobotany, zooarchaeology, anthropology, geophysical prospection as well as chemical and technological studies of metal, stone and pottery. Hardly any other archaeological project is supported so intensely and on such a broad scale by archaeometric investigations as the international research group in Troia. In April 2001 an International Symposium was held in Heidelberg, Germany, with the aim of promoting scientific interaction and providing synopses of the various disciplines engaged in Troia. This volume contains most of the contributions presented at the symposium.