Simon remained on his estates in France, where in 1209 he was elected captain-general of the French forces in the Albigensian Crusade by his fellow nobles, reportedly after several larger players had turned down the role. He was present at the siege and subsequent massacre at Béziers on 22 July 1209 when the entire population of twenty thousand Cathars and Catholics were slaughtered.
Thousands sought sanctuary in the Cathedral of St Nazaire which was set on fire and also in the Eglise de la Madeleine inside which all were butchered to death.”Tuez les tous, Dieu reconnaitra les siens” – “Kill them all, God will recognize his own” was the famous quotation which exonerated the rampaging Crusaders. Ironically it was Ste Madeleine’s Day. Simon was rewarded with the territory conquered from Raymond VI of Toulouse which in theory made him the most important landowner in Occitania. He became notorious and feared for his extreme cruelty, massacring whole towns, and for his “treachery, harshness, and bad faith.” In 1210 he burned 140 Cathars in the village of Minerve who refused to give up their faith. In another widely reported incident, prior to the sack of the village of Lastours, he brought prisoners from the nearby village of Bram and had their eyes gouged out and their ears, noses and lips cut off. One prisoner, left with a single good eye, led them into the village as a warning.
Simon’s part in the crusade had the full backing of his liege lord, the King of France, Philip Augustus, although historian Alistaire Horne, in his book Seven Ages of Paris states that Philippe (sic) “turned a blind eye to Simon de Montfort’s brutal crusade…of which he disapproved, but readily accepted the spoils to his exchequer”(36). Following the latter’s success in winning Normandy from John Lackland of England, he was approached by Innocent III to lead the crusade himself but turned this down being heavily committed to defend his gains against John and against the emerging alliance between England, the Empire and Flanders. However, Phillip claimed full rights over the lands of the house of St Gilles and some have seen his dispatch of de Montfort and other northern barons as at the very least an exploratory campaign to reassert the rights of the French crown in Le Midi. He may well also have been wishing to appease the papacy after the long dispute over his marriage which had led to excommunication – as well as seeking to counter any adventure by John of England – who had marriage and fealty ties also with the Toulouse comtal house. Meanwhile others have seen Phillip’s motives as including removing over-mighty subjects from the north, distracting them in adventure elsewhere where they could not threaten his increasingly successful restoration of the power of the French crown in the north.
Simon is described as a man of extreme religious orthodoxy, deeply committed to the Dominican order and the suppression of heresy. Dominic Guzman, later Saint Dominic, spent several years during the war in the Midi at Fanjeau, which was Simon’s headquarters, especially in the winter months when the crusading forces were depleted. Simon had other key confederates in this enterprise which many see as a naked seizure of southern lands by ambitious men from the north, many of whom had been involved in the notorious fourth crusade. One of these was Guy Vaux de Cernay – head of a Cistercian abbey not more than twenty miles from Simon’s patrimony of Montfort Aumary – who accompanied the crusade in the Languedoc and became bishop of Carcassonne for his pains. Meanwhile the nephew of Guy, Peter de Vaux de Cernay, arguably a stool-pigeon of De Montfort,his uncle and the papacy, wrote an account of the crusade which many have seen as a transparent piece of propaganda to justify the actions of the crusaders, whose outrages are described consistently as doing the work of God against the heretical agents of the demonic power – while outrages committed by the embattled lords of the Midi are predictably portrayed as the opposite. Simon was an energetic campaigner, making rapid movements to strike at those who had broken their faith with him – and there were many as local lords switched sides whenever the moment seemed propitious. The Midi was a warren of small fortified places, as well as home to some of the most magnificent defended cities – such as Toulouse, Carcassonne and Narbonne. Simon seems to have shown great personal valour and daring as well as being particularly brutal with those close to him who betrayed him – as for example, Martin Algae, lord of Biron. In 1213 he defeated Peter II of Aragon at the Battle of Muret. The Albigensians were now crushed, but Simon carried on the campaign as a war of conquest, being appointed lord over all the newly-acquired territory as Count of Toulouse and Duke of Narbonne (1215). He spent two years in warfare in many parts of Raymond’s former territories; he besieged Beaucaire, which had been taken by Raymond VII of Toulouse, from 6 June 1216 to 24 August 1216.
Raymond spent most of this period in Aragon, but corresponded with sympathisers in Toulouse. There were rumours that he was on his way to Toulouse in September 1216. Abandoning the siege of Beaucaire, Simon responded with a partial sacking of Toulouse, perhaps intended as punishment of the citizens. Raymond actually returned to take possession of Toulouse in October 1217. Simon hastened to besiege the city, meanwhile sending his wife, Alix de Montmorency, with bishop Foulques of Toulouse and others, to the French court to plead for support. After maintaining the siege for nine months Simon was killed on 25 June 1218 while combating a sally by the besieged. His head was smashed by a stone from a mangonel, operated, according to the most detailed source, by donas e tozas e mulhers (“ladies and girls and women”) of Toulouse. He was buried in the Cathedral of Saint-Nazaire at Carcassonne. His body was later moved, however to Montfort l’Amaury by his son. There is still a tombstone in the Cathedral called “of Simon de Montfort” in the South Transept.
Salle des illustres au Capitole de Toulouse, ville de Toulouse, région Midi-Pyrénées (France) : Raymond VI annonce à la ville de Toulouse la mort de Simon de Montfort 1218, Labatut.