Guillaume III (I) De+ Bethune
Guillaume III (I) De+ was born about 1184 in Meulebeke, Flandre-Ouest, Belgium.  He died on August 24th, 1243 in Lokeren, Flandre-Orientale, Belgium.

 Elizabeth De Roesbrugge
Elizabeth De was born about 1185.

 Guillaume II De Bethune
Guillaume II De was born about 1217.  He died after 1247.