Mathieu De Saint Simon
Mathieu De was born about 1375.  He died on October 25th, 1415 in Battle of Azincourt.

 Jeanne De Haverskerke-Wicke
Jeanne De was born about 1380.

 Gaucher De Saint Simon
Gaucher De was born about 1398.  He died after January 5th, 1458.

 Gilles De Rouvroy De Saint Simon
Gilles De Rouvroy De was born about 1400.  He died in 1477.