De Montfort's son could make no headway against a people in arms. But in 1222 Raymond VI and Philip of France vainly tried to promote a peaceful settlement between Amaury de Montfort and Raymond VII. Amaury, despairing of success, offered his claims to the French King, and in 1223 Philip's successor, Louis VIII, overpersuaded by the Pope, accepted them. The young Count Raymond vainly endeavoured to ward off the threatened invasion and showed every desire to be reconciled with the Church. There was scarcely any longer a pretence of religious war. From the first it had been largely a war of races, promoted by northern jealousy at the wealth and civilisation of the south and by a desire for the completion of the Frank conquest of Gaul. Thus from the beginning of hostilities the whole population of the south, Catholic as well as heretic, had stood together in resistance to the crusading army, and despite his tergiversations Raymond VI had never lost their affection and support. The war lasted for three years (1226-9); Louis VIII led an expedition southwards, which for some inexplicable reason turned back before it had achieved complete success; and after his death the Queen-Regent, Blanche of Castile, with the encouragement of Pope Gregory IX, came to terms with Raymond VII. By the Treaty of Meaux (1229) Count Raymond agreed to hunt down all heretics, to assume the cross as a penance, to give up at once about two-thirds of his lands, while the remainder was to go to his daughter, who was to be married to a French prince, with the ultimate reversion to the French Crown. In 1237 Jeanne of Toulouse was married to Alfonso, brother of Louis IX; in 1249, on the death of Raymond VII, they succeeded to his dominions, and on their death in 1271 without children Philip III annexed all their possessions to the dominions of the French Crown. [Sidenote: Punishment for heresy.]