Isabeau de Châtillon
Isabeau de Châtillon (c. 1295 – 19 May 1360) was the daughter of Guy IV, Count of Saint-Pol, and Marie of Brittany. As lady of Encre she married in 1311 at Pontoise, before Philip the Fair, the Picard baron Guillaume I de Coucy.
Her children included Enguerrand VI, killed at Crécy in 1346, and Raoul. Widowed in 1335, she kept Oisy as her dower and was styled its lady in 1351.