He was described by Matthew Paris as "a discreet and circumspect man, who was also skilled and experienced in the affairs of war".
He was a supporter and comrade-in-arms of Louis IX of France, who helped him be elected Grand Master in place of Guillaume de Sonnac, killed in Egypt at the Battle of Mansura, February 11, 1250.
Guillaume Apollinaire | Guillaume Dufay | Guillaume Brahimi | Guillaume de Machaut | Guillaume-Chrétien de Lamoignon de Malesherbes | Robert Guillaume | Guillaume | Toussaint-Guillaume Picquet de la Motte | Guillaume Thomas François Raynal | Guillaume Lejean | Arnaud Guillaume de Barbazan | Alfred Guillaume Gabriel, Count D'Orsay | Pierre Guillaume | Louis Augustin Guillaume Bosc | Jean Guillaume Bruguière | Jean Guillaume Audinet-Serville | Jean-Baptiste Claude Eugène Guillaume | Guillaume Groen van Prinsterer | Guillaume Grandidier | Guillaume Dupuytren | Guillaume Dubois | Guillaume du Bellay | Guillaume Depardieu | Guillaume de Nogaret | Guillaume Dasquié | Guillaume Couillard | Guillaume Canet | Guillaume Bigot | Guillaume-Antoine Olivier | Bois-Guillaume |