Quem se casou com Mary d'Enghien?

John, Count of Brienne (c. 1235 – c. 1260) was the eldest son of Walter IV of Brienne and Marie of Cyprus.

He inherited the County of Brienne on his father's passing in 1246, but preferred to live among his mother's relatives at the court of Cyprus, and played little part in international politics. In 1255, he married Marie, Lady of Thieusies (in Hainaut), the daughter of Sohier II of Enghien. His wife and he had no children, and when he died, he was succeeded by his brother Hugh.

Hugh IV, Count of Rethel (1244–1285) was a son of Manasses V and his wife, Isabelle of Écry. In 1272, he succeeded his father as Count of Rethel.

Hugues IV was married to:

• Agnes of Chiny
• Marie of Enghien
• Isabelle of Grandpré

With Isabelle, he had a daughter, Jeanne, Countess of Rethel, who succeeded him. In 1290, Jeanne married Louis I, Count of Flanders.