Sybil was referred to as the niece of Henry I of England but is commonly believed, probably incorrectly, to be one of his illegitimate children.
Boelare is now known as NederBoelare and is part of the town of Geraardsbergen, East Flanders, Belgium.
The de Boulers were based at Hen Domen, the original site for Montgomery Castle and it is from Baldwin that Montgomery gets its Welsh name, Trefaldwyn "The Town of Baldwin".
The de Boulers continued as a prominent Shropshire family, becoming the Bowdlers.
Sibyl of Falaise married Baldwin de Boulers] 1st Lord of Montgomery (sometimes spelled Bullers), at the instigation of Henry I of England.