When Pope Innocent III called for a crusade against the "Albigensians," or Cathars, in Languedoc in 1208, Philip did nothing to support it, though he did not stop his nobles from joining in. The war against the Cathars did not end until 1244, when their last strongholds were finally captured. The fruits of the victory, the submission of the south of France to the crown, were to be reaped by Philip's son Louis VIII and grandson Louis IX. From 1216 to 1222, Philip also arbitrated in the War of the Succession of Champagne and finally helped the military efforts of Duke Odo III of Burgundy and Holy Roman Emperor Frederick II to bring it to an end.