In the Roman world, slavery played a fundamental role: slaves performed all kinds of manual labour and domestic services, but some had highly skilled professions. Besides private slaves, owned by private masters, and imperial slaves, who were in the property of the emperors, there were the so-called public slaves (servi publici): they were non-free individuals owned not by a private person, but by a community, such as the Roman people as whole or by the citizen body of a municipality. Public slaves were considered as a state chattel, in much the same way as occurred in the Ancient Greece and in some modern slave-owning societies.

The goal of the SPES project was to provide a full-scale reconsideration of the position of public slaves in the Roman history, economy and society, through a multidisciplinary and comparative study.