Robert de Pierrepont
Robert was born about 1060 in Pierrepont, Neufchatel, Seine-Inferiure, Normandy, France.  He died about 1085.

 Ermengarde de Montagu
Ermengarde was born in 1063 in Montaigu, Nantes, Anjou, France.  She died at the age of 60 in 1123.

 William de Pierrepont I
He died about 1154.