 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.