Thierry I De Walcourt
Thierry I De was born about 1110.  He died about 1148.

 Mathilde De La+ Roche
Mathilde De La+ was born about 1120 in La Roche-en-Ardennes, Luxembourg, Belgium.

 Wery III De Walcourt
Wery III De was born about 1145.  He died on June 29th, 1206.