He is married to Mabel van Engeland.
They got married about 1122.Source 3
Child(ren):
Ook Willem IV van Montmiral
https://nl.wikipedia.org/wiki/Theobald_IV_van_Blois
https://fr.wikipedia.org/wiki/Perche-Gou%C3%ABt#Guillaume_Gou%C3%ABt_IV
https://fr.wikipedia.org/wiki/Perche-Gou%C3%ABt#Guillaume_Gou%C3%ABt_III
https://fr.wikipedia.org/wiki/Perche-Gou%C3%ABt#Guillaume_Gou%C3%ABt_II