Lord Walter d'Oisy I of Avesnes
Walter was born in 1110.  He died at the age of 37 in 1147.

 Ada of Montagne
Ada was born in 1100.

 Lord Nicholas ("Plukiel") d'Avesnes
Nicholas, known as "Plukiel", was born in 1129 in Oizy, Namur, Belgium.  He died at the age of 42 in 1171 in Avesnes, Artois/Pas-de-Calais, France.