The historian Frederick William Maitland was fond of reminding the scholars of his generation to "think the thoughts of medieval men as they thought them" . To assess the achievements of Louis IX we must try to think his thoughts. We cannot make assessments based on what we perceive to be achievements in this age, as this will invariably lead us to false conclusions. From a detached perspective Louis was a golden king. His administration was second to none. His reputation internationally was unexcelled both in his role as arbiter for other countries, peacemaker in his own and, as William Chester Jordan remarked on his securing of the Languedoc "his rapid assimilation of this region must be accounted as one of the most extraordinary accomplishments in medieval history" . There can be no doubt that if Louis' aim was to be a just and pious ruler and create a harmonious...