The descent cited below is undocumented.

According to Medieval Lands, Guillaume's parentage is unknown and he had only one wife, Havoise (parentage unknown). It would further appear that the Rochefort connection stems from Guillaume's son Anseau marrying a daughter of Guy II "le Rouge" (de Montlhery), Comte de Rochefort.
http://fmg.ac/Projects/MedLands/PARIS%20REGION%20NOBILITY.htm#_Toc4...

Gui de Monthlery, Count of ROCHEFORT

   * Father: Guy, Seigneur of MONTHLERY

* Mother: Hodierne de GOMERTZ
* Birth: 1025/1055
* Partnership with: (Unknown)
o Child: Anselm de Garlande, Count of ROCHEFORT Birth: 1042/1078
o Child: Gilbert dit Payen de GARLANDE Birth: 1042/1072
o Child: Etienne (Stephen) de GARLANDE Birth: 1042/1078
o Child: Guillaume de GARLANDE Birth: 1042/1078
Ancestors of Gui de Monthlery, Count of ROCHEFORT

       /-Guy, Seigneur of MONTHLERY

Gui de Monthlery, Count of ROCHEFORT

       |         /-William I De Gometz, Seigneur of BURES

\-Hodierne de GOMERTZ
Descendants of Gui de Monthlery, Count of ROCHEFORT

1 Gui de Monthlery, Count of ROCHEFORT

 =(Unknown)

2 Anselm de Garlande, Count of ROCHEFORT
= MONTLHERY
3 Agnes of GARLANDE
=Amauri II (or IV) of Montfort, Count of EVREUX Marriage: 1095/1126
2 Gilbert dit Payen de GARLANDE
2 Etienne (Stephen) de GARLANDE
2 Guillaume de GARLANDE

For his heraldic shield, see "My Lines"

( http://homepages.rootsweb.ancestry.com/~cousin/html/p214.htm#i24152 )

from Compiler: R. B. Stewart, Evans, GA

( http://homepages.rootsweb.ancestry.com/~cousin/html/index.htm )