As reported by both Albert of Aix and William of Tyre, Lambert and his brother Gozelo took a major role in the First Crusade,[1] participating in the Siege of Nicaea in 1097.
Lambert was present at the siege of Acre in 1098, which finally fell after four years.
He commanded one of the corps of the army of Godfrey of Bouillon, resulting in the capture of Antioch in 1098.
Along with his father and Peter the Hermit, he founded Neufmoustier Abbey.
The speculation on the second possibility is based on the connection between Lambert and the Counts of Clermont, but that connection is best explained by his paternal grandmother’s relationship with Clermont.