Isabeau De was born about 1328. She died before 1369.
General Notes
SOURCES: "Ancestors/Descendants of Royal Lines" (Contributors: Reynaud de Paysac, H.R. Moser <Burke Peerage>), O.Guionneau, E. Polti, A.Terlinden <Genealogy of the existing British Peerage, 1842, and E. Lodge>)