Notes for Enguerrand III Couci Baron de Coucy
From Bruce McAndrew’s “Scotland’s Historic Heraldry”, p. 30, he had three wives:
1. N.N.
2. Mahaut de Saxe,
3. an heiress of Montmirail.
It is not known which of these wives was the mother of Mary. McAndrew includes that Mary had a sister Alix who m. Arnold II, count of Guines and from their second son, Enguerrand V de Coucy, descended Enguerrand VII de Coucy who was made earl of Bedford in 1366.