GEOFFROY [III] de Mayenne (-18 Feb or 25 Jul 1169). "Juhello principe Meduane et uxore eius Clementia et filio eorum Gaufrido primogenito" subscribed a charter dated 12 and 26 Jul 1128, under which property was restored to the abbey of Mont-Saint-Michel[726]. He succeeded his father in 1161 as Seigneur de Mayenne. He went on crusade in 1163[727]. m firstly CONSTANCE de Bretagne, daughter of CONAN III Duke of Brittany & his wife Matilda [of England] (-1148). The primary source which confirms her parentage and marriage has not yet been identified. m secondly ([1161]) as her first husband, ISABELLE de Meulan, daughter of GALERAN de Beaumont-le-Roger Comte de Meulan & his wife Agnes de Montfort Dame de Gournay-sur-Marne (-10 May 1220, bur Savigny). The primary source which confirms her parentage has not yet been identified. Her two marriages are confirmed by the undated charter by which her son "Mauritius dominus Credoni" confirmed the donation by "Constantia soror mea" of revenue set by "dominus Juhellus frater meus" at "apud Harperiam" to the abbey of Clarei, by undated charter, witnessed by "…domina Isabel matre mea, domina Gervasia…"[728]. She married secondly ([1170]) Maurice [II] Sire de Craon. Henry II King of England confirmed a donation to Savigny by "Ysabell filie Gualerandi comitis de Mellento", with the consent of "filiis suis Juhello…filio Gaufridi de Meduana, et Mauricio et Petro, filiis Mauricii de Creon", by charter dated to [Apr 1180/Jan 1183][729]. "…Isabel uxore mea et filiis meis Mauritio et Petro et Philippo de Sauconeio, Paganus de Sancto Amatore, Guillelmi de Vitreio et Mauritius frater eius" witnessed the charter dated 1191 under which "Mauritius de Credone Hugonis filius" confirmed donations to "ecclesiæ de Rota"[730]. "Mauritius de Credone filius Hugonis" appointed "meæ uxoris Isabel" as guardian of his lands and his children in his undated testament when leaving for Jerusalem[731]. The Chronicon Savigniacensis Monasterii records the death in 1220 of "Juhellus de Meduana…domina Isabel mater eius"[732]. The Gesta Guillelmi Majoris Andegavensis Episcopi names "dominis de Credonio…et Isabella Domina de Credonio" among those present at the burial of Bishop Guillaume, undated but stated to be during the reign of Philippe II King of France[733]. The Chronicon Savigniacensis Monasterii records the death in 1220 of "Juhellus de Meduana…domina Isabel mater eius"[734]. Geoffroy and his [first][735] wife had one child