 In the theological debates in the early 13th century between the Cathars and the Papal representatives, he presented the Cathar arguments, thus at the Debate at Montreal in 1206 and at the last Debate at Pamiers where he encountered Saint Dominic in 1207, prior to the Albigensian Crusades.In 1193, Guilhabert settled in Fanjeaux where he attended to a group of Perfects and believers until Simon de Montfort took the town during the Albigensian Crusade in 1209.Guilhabert withdrew to the Château de Montségur and ministered from its safety.