Several internet sources have Nicholas b. 1191, d. aft 1261 and son of William I de Cantelou and Mecelin de Braci. Many of these same sources have Nicholas having a son William b. 1225 by Eustache, who wasn't born until 1250. Even without this impossible birth, I think that the age difference of 50 to 60 years would preclude a marriage. In 1261, Eustache was only 11 years old. The younger Nicholas born to William II de Cantelou makes much more sense. Even though I find references in MCS and AR to Nicholas, they only refer to him as 1st husband of Eustache, without giving any dates or lineage.