Trust and the loss of trust are not only omnipresent in modern discourse, but also represent phenomena of timeless significance that are particularly important for the understanding of ancient societies. For the first time, the contributions to the conference volume deal with this complex topic systematically from an interdisciplinary perspective. Based on fundamental concepts of trust in the Greek and Roman world, questions about the circumstances and conditions of the erosion of trust are considered as well as the dimensions and effects of lost trust.