Guillaume II Chatelain De St. Omer
Guillaume II Chatelain De was born in 1070 in France.  He died about 1143.

 Melisinde De Picquigny
Melisinde was born in 1070 in Picquigny,Picardy,France.¹   Melisinde is no longer alive.¹ 

 Guillaume III De St. Omer
Guillaume III De was born in 1105 in France.  He died at the age of 65 in 1170.

 Mahaut De St. Omer
Mahaut De was born in 1110 in St. Omer,Pas-De-Calais,Normandy,France.