MATHILDE de Breteuil (-14 Mar 1208). The Chronicle of Alberic de Trois-Fontaines names "comitissam Clarimontis Belvacensis et uxorem Symonis Clarimontis et Emiciam" as the three daughters of "Alaydis [filia comitem de Brana Robertum domnum]" & her first husband[827], although it appears chronologically unlikely for Mathilde, wife of Simon de Clermont, to have been the daughter of Valeran [III] by his second wife. The correct parentage of Alix and her sister Mathilde is confirmed by the charter dated 1153 which records that “Galerannum de Britoglio” donated property at Champmartin at Rueil-sur-Bèche to Froidmont abbey, with the consent of “Hugone fratre suo...et Holdeburge uxore Galeranni, Aalsi et Mathilde filiabus eius”[828]. Dame d’Ailly: [the widow of her grandson] “Gertrudis domina Alliaci...Joannes filius meus” confirmed the donation of land “apud Beeleuses in decima quam emit Matilidis de Alliaco mater predicti Radulfi” made by “Radulfus de Claromonte quondam maritus meus” by charter dated 1225[829]. “Radulfus...comes Clarimontis et dominus Britolii” reached agreement with Lannoy abbey over “feodis meis in Montania”, with the consent of “uxore mea comitissa Aeliza et filia mea Katerina et fratre meo Symone cum uxore sua Matilde”, by charter dated 1174[830]. "Dnus Symon de Alliaco" donated property to Saint-Leu d’Esserent, with the consent of "Matildis uxor eius et filii eius Radulfus et Guido et Dnus Robertus de Bova", by charter dated to before 1191, but received 1193, signed by "Rodulfus comes de Claromonte…"[831]. m SIMON de Clermont Seigneur de'Ailly-sur-Noye, son of RENAUD Comte de Clermont-en-Beauvaisis & his [second wife Clémence ---] (-after 1187).