 From that moment on, Pierre de La Brosse was Philip's mentor.His father, Louis, also provided him with advice, writing in particular "Enseignements", which inculcated the notion of justice as the first duty of a king.According to the terms of the Treaty of Corbeil (1258), concluded on 11 March 1258 between Louis IX and James I of Aragon, Philip was married in 1262 to Isabella of Aragon in Clermont by the archbishop of Rouen, Eudes Rigaud.