Confronting the Iranian negotiation culture to French legal traditions casts a new light on two key events i.e. the Islamic conquest of Iran and the French Revolution. In Iran, a thousand years of invasions have given birth to a culture running counter to French legal traditions. Whereas an aristocratic negotiation style survives in medieval France, the Persian elites, brought into disrepute by Arabic conquerors, invent sophisticated conflict-resolution means in order to ensure their own survival. Inertia is thus used as a means to resist foreign domination. A spontaneous law system spawns, set up by brokers. The vanquished élites, haunted by foreign conspiracies, use ambiguous and indirect speeches in order to retain power. Simultaneously, Iranian legal sources reveal striking similarities between Safavid Persia and early modern French culture. The weight of the clergy within the State, the importance of history or the art of conversation are shared by both French and Persians. Parallels can be drawn between the Persian metaphorical speeches and the baroque taste for illusion or the politeness of the Iranian merchants with the French court etiquette. The early modern period proved a time of cultural proximity which, however ended with the French revolution. Its cultural and legal consequences can be considered as the starting point of a growing gap between France and Persia. Remembering invasions and searching for the perfect ambassador thus constitute two major features, whose neglect has led to wide cultural and legal misunderstandings between Persia and France.