¿Quién se casó con Eustaquia de Courtenay?

Guillaume de Brienne, né vers 1168 et mort en 1199, est un seigneur de Pacy-sur-Armançon. Il est le fils d'Érard II, comte de Brienne, et d'Agnès de Montbéliard.

Guillermo I de Champlitte (en francés: Guillaume de Champlitte; aprox. 1160 - 1209) fue un caballero francés que se unió a la cuarta cruzada y se convirtió en el primer príncipe de Acaya (1205–1209).​​​

William I of Sancerre (French: Guillaume de Sancerre, ca. 1176 – 1217) was the second Count of Sancerre, Lord of Saint-Brisson and La Ferté-Loupière from 1191 until his death. He was the eldest son of Stephen I, Count of Sancerre. In 1217 he accompanied his brother-in-law, Peter II of Courtenay, who had just been elected Latin Emperor, on his journey to Constantinople. Both were captured and imprisoned by the ruler of Epirus, Theodore Komnenos Doukas, and died in prison. He was succeeded by his son, Louis I.