"Willelmus comes" donated property to Cluny by charter dated 28 Aug [990] signed by "Rodbaldus comes, Adalaix comitissa, Wilelmus comes et filius eius Wilelmus". According to Europäische Stammtafeln, he was the son of Comte Guillaume by his first wife but the primary source on which this is based has not been identified. It is possible that it is speculative in light of his marriage date, which suggests that he was born earlier than the date of his father's second marriage. GUILLAUME [III] Comte de Provence 992, minor until 994 .
La fecha de defunción de Arsinda, su supuesta madre, que algunos historiadores fijan en torno al 979, provoca la confusión. Para otros, que sitúan el fallecimiento de Arsinda antes del 983, no existe forzosamente imposibilidad.
