Guillaume took part in the Third (1188–92) and Fourth Crusades (1201–4), and died in Romania as part of the latter. A reference in the Vidame's song "Combien que j'aie demouré" to a forced sojourn in a "hated land" probably refers to Guillaume's stay in southwestern France in 1188, before the departure of the Crusade, while the leaders (Richard the Lionheart and Philip Augustus) were squabbling. Further evidence linking the trouvère with Guillaume includes a quotation of two stanzas of the Vidame's most popular song, "Quant la saison du dous tens s'asseure", in the chivalric romance "Guillaume de Dole", which was written probably in the 1220s. "Quant la saison" was, by implication, written some years prior. The rather garbled and uncertain melodies which accompany the Vidame's poems further support an early (pre-1200) date for the trouvère. One piece of evidence relating to the identity of the Vidame has not yet been adequately explained. The coat of arms with which the trouvère is depicted in his miniature portrait in the Chansonnier du Roi belonged mid-century to the Meslay family, who became vidames of Chartres only in 1224.