James I of Aragon dedicates a couple of chapters to his mother Maria of Montpellier and his father Peter II of Aragon (called "Peter the Catholic"), who had been given the title of ""Rex Catholicissimus"" by the Pope after the Battle of Las Navas de Tolosa in which he helped Alfonso VIII of Castile fight against the Moors, one year before his death. Peter II of Aragon died defending his vassal lords of Occitania, who were accused of allowing the Cathar heresy to proliferate in their counties. He was killed in the Battle of Muret, fighting against the Crusader troops commanded by Simon de Montfort. Though the text of the "Llibre dels fets" was dictated and edited by James I, the actual writing was done by scribes, not James himself; it is written is colloquial language, representing the native tongue as spoken, and its style is direct.