The Plantagenet Ancestry, by William Henry Turton, 1968 @ 13

(Ref: 13) This citation is considered to be direct and primary evidence used, or by dominance of the evidence.
The Plantagenet Ancestry, by William Henry Turton, 1968. 

• References (4)
  • Parent Source: The Plantagenet Ancestry, by William Henry Turton, 1968
  • Individual: William (Guillaume) III Count Of Ponthieu
  • Individual: Beatrice De St. Pol
  • Individual: Jean I de Ponthieu