*Eustace III de Rouex

*Eustace III's father was *Eustace II de Rouex and his mother was *Bertha de Gavre.  His paternal grandparents were *Eustace I de Rouex and *Marie le Mons; his maternal grandparents were *Bertrand (Rasse IV) de Gavre and *Ida (Domnison) de Chievres.  He was an only child.

They had a daughter named *unknown.