Nicholas d'Oisy d'Avesnes
He died in 1169.¹ 

 Mathilde de Namur
Mathilde was born in 1120.¹   Mathilde is no longer alive.

 Jacques d'Avesnes
Jacques was born in 1150.¹   He died as a war casualty, battle - 3rd Crusade, at the age of 41 on September 7th, 1191 in Arsouf, Palestine.¹