He is married to Béatrix de Clermont en Beauvais.
They got married about 1104.Source 1
Child(ren):
euweb.direaumont1.html
B1. [2m.] Cte Mathieu I de Beaumont, +1.1.1155; m.before 1101 Beatrix, dau.of Hugues de Clermont-en-Beauvaisis by Marguerite de Montdidier
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file:///M:/!GRABS/OlijuseB_Frans/src/olijuseb.free.fr/ascendant/pafg55.htm#107
Mathieu I de Beaumont sur Oise | |||||||||||||||||||||||||||||||||||
± 1104 | |||||||||||||||||||||||||||||||||||
Béatrix de Clermont en Beauvais |
http://vandermerwede.net// n/a