Robert IV Le Gros De Béthune
Robert IV Le Gros was born in 1065.  Robert IV Le Gros is no longer alive.

 Alix De Péronne
Alix was born in 1075.  Alix is no longer alive.

 Guillaume Ier De Béthune
Guillaume Ier was born in 1100.  He died at the age of 44 in 1144.