John I of Brienne, Count of Eu French count (1250–1294) Parents Marie of Lusignan, Countess of Eu Alphonso of Brienne Children John II of Brienne, Count of Eu Jeanne de Brienne Maud de Brienne Isabeau de Brienne Margaret de Brienne Margaret d'Eu Siblings Hugh, Count of Brienne Raoul d'Eu Blanche d'Eu Isabeau de Brienne Margaret d'Eu Partners Béatrice de Châtillon