This collective volume, originating from an interdisciplinary conference at Heidelberg University, deals with the expansion of the so-called oriental cults in the Roman Empire. The concept of 'oriental cults' itself has come under discussion in recent years because it has been questioned whether the cults in question really formed a coherent group and to what degree they might be called 'oriental' at all. This discussion is reflected throughout the papers of the volume which focus on the three cults of Isis (and Osiris), Mithras and Jupiter Dolichenus. Of special interest are the (alleged) origins of these cults in Egypt, Persia and Northern Syria, their expansion and adaptation within the Roman Empire (through some sort of 'religious flows'), their linguistic and visual expressions as well as the architecture and decoration of sanctuaries and the rituals connected with them.