He participated in the First Crusade (1096–99) with his son Enguerrand, where they both won fame as military leaders.
Being vassals of Eustace III of Boulogne, they probably travelled east in his company, among the retinue of Godfrey of Bouillon.
Hugh and Enguerrand participated in the Siege of Antioch in 1098, where they were central in raiding the Turkish forces.
After Baldwin's death, he entered the coalition formed by Robert's widow Clementia of Burgundy, with the aim of unseating Charles the Good from the county Flanders and giving it to William of Ypres.
Charles triumphed over this coalition and, upon entering the county of Saint-Pol, razed all the fortresses and forced the count to offer peace in exchange for restoring the sovereignty of Flanders in the region.