Guilliaume de Montfort He fought in the First Crusade, but was killed there in battle on 27 August 1101. Guilliaume de Montfort Guilliaume de Montfort () (died 27 August 1101) was a French bishop, most notably the Bishop of Paris from 1095 to 1101. Montfort's date of birth is not known, but it was some time before the death of his father, Simon I de Montfort in 1087. He was Bishop of Yves some time before becoming the Bishop of Paris. In 1095, Pope Urban II held the Council of Clermont at Clermont-Ferrand, France. It excommunicated Philip I of France and Bertrade de
Geoffrey of Vendôme monastery to Popes Urban and Paschal. He took part in the councils held at Clermont in 1095, by Pope Urban; at Saintes, in 1096, by the Apostolic Legate Amatus of Bordeaux; and at Reims, in 1131, by Innocent II (1130–43). He also strenuously defended the ecclesiastical principles in the question of investitures, which he qualified in several small tracts as heresy and simony; he wrote in the same spirit to Pope Paschal II when the latter made concessions (1111) to Emperor Henry V (1106–25). Finally, he always defended firmly the prerogatives, the rights, and the property of his abbey at