It showed Montfort had no equal as a battlefield commander, having now after his previous exploits defeated, against all odds, a man whose status as a sovereign king, general and crusader matched or exceeded the Frenchman's own reputation.

The outcome of the battle removed Aragonese influence over the Languedoc and its surrounding provinces and allowed the Crown of France to assert its own control over them, which led to an expansion of the French royal domain further south.

[20] Simon IV de Montfort was the leader of the Albigensian Crusade aimed at destroying Catharism and bringing the Languedoc under Capetian control.

Count Raymond sought assistance from his brother-in-law, King Peter II of Aragon, who felt threatened by Montfort's conquests in Languedoc.

According to Laurence Marvin, Simon de Montfort led an army of 1,000–1,700 French Crusaders, including a small contingent of knights brought by his ally, the Viscount of Corbeil.

[1][21] Spencer C. Tucker specifically gives 700 infantry and 900 cavalry under Simon de Monfort for a total of 1,600 men,[22] which is fairly close to the former author's higher estimates.

However, Pierre des Vaux de Cernay, the primary contemporary source about the battle, puts the total allied army at an impossible 100,000 men and claims casualties to have numbered as high as 20,000.

[24] Charles Oman, however, states there may have been 1,900 to 2,100 total allied horsemen and 15,000 to 20,000 infantry, of which the burgess militia of Toulouse must have formed the most solid portion.

Oman thus implied the allied infantry ranks were not exclusively filled with Toulousain militiamen, pointing out that at the news of Peter's approach, the men of Languedoc took arms on all sides and the Counts of Toulouse and Foix were able to assemble a "large army" beneath their banners.

When they saw the Crusader horsemen returning and learned that King Peter of Aragon had been killed,[31] they broke and fled their fortified camp toward the Garonne River but were slaughtered in the rout.