Diplomatic relations involve the organisation of legitimate mobility of the negotiators as well as the regulation of forms of hospitality where legal rules are reinforced by usages. In the 18th century, the Résidents de France in the Republic of Geneva faced a number of constraints related to the journeys between Paris and the Legation, constraints that were both material and symbolic in nature. In addition to travel expenses and difficulties to make progress given the poor state of the roads, the ceremonial of crossing the border expressed in a ritualised manner the interaction between two sovereign states that differed in terms of political and religious identity. Part of the exchange of diplomatic gifts, the commensality at the end of the journey mobilised economic resources and specific knowledge, while conveying the prestige of the hosts and the hierarchic ranks of the invitees. At the same time, however, the institution of commensality needs to be viewed from a perspective that construes diplomacy as a system of cultural interactions.