The project of Francesco Mari examines the sources for diplomatic contact among the three ancient cultures of Greece, Rome and the Near East, focusing on ritual aspects. In antiquity, ambassadors’ behaviour was guided by a ritual, shared code of communication allowing to express the mutual willingness of the parties to cooperate. By a close comparative analysis of the available evidence, however, it is possible to show that misunderstandings about the correct interpretation of specific symbolic practices were also frequent, and that it often concerned the core values upon which agreements were based.