The conquest of the Kingdom of Sicily by Charles d’Anjou in 1266 placed the capetian dynasty in an unprecedented situation: the brother of the King of France became King himself. Relations between ‘Angevins de Naples’ and Capetiens de France have not been studied as such; they were most often caricaturated, particularly in connection with the explanation of the two cruises in Philippe III, Tunis in 1270 and Aragon in 1285. The purpose of this work is to look at the relationship between Charles d’Anjou and his nephew Philippe III in the 1270s. After nuancing the traditional interpretation of a distance between the two classes, it is possible, especially thanks to angevine sources, to show that relations have been close on the contrary: still in need of money, Charles d’Anjou has often used the French Royal Treasury; on the other hand, the King of Sicily had almost permanent representatives at the court of France, who were contacted by temporary envoys in charge of a particular point. Charles d’Anjou also maintained close contact at the court with a number of princes, including his nephew Robert d’Artois, and sought to reconcile the privilege of Philippe III’s favourite Pierre de la Broce. Finally, the surroundings of the two kidneys were so similar that there were many who, like Jean Britaud for example, were in their place in the court of France as well as in the court of Naples. In these circumstances, it is not surprising that the two king had not a common policy, but important points of convergence: after a draft candidacy for Philippe III’s imperial throne steered by Charles d’Anjou, the agreement is most obvious around the pontifical elections and the latest institutions in the Holy Earth. In the Holy Earth, the French contingent offers unwavering support to the companies of the King of Sicily, which became King of Jerusalem: this episode not only illustrates the convergence of views between the King of France and his uncle, but also shows the natural solidarity that unites the French nobility scattered in the Mediterranean, from the Kingdom of France to the Holy Earth, the Kingdom of Sicily and France. Hélary Xavier. Relations between the courts of France and Naples in the 1270s. In: The Mediterranean political space. Acts of the 128th National Congress of Historical and Scientific Societies, Relations, Exchange and Cooperation in the Mediterranean, Bastia, 2003. Paris: CTHS Editions, 2008 pp. 33-46. (Acts of the National Congress of Historical and Scientific Societies, 128-17)