Britain's Royal Families: The Complete Genealogy @ p 46
The cited information was published by rev. ed, Pimlico Random House, London 1989, 1996 (Ref: p 46) The author/originator was Alison Weir.
References (2)
Parent Source:
Britain's Royal Families: The Complete Genealogy
Family:
Henry Beauclerc & Matilda Dunkeld