The sources which report the parentage of the wife of Gilbert de Lacy are conflicting. A manuscript which narrates the descents of the founders of Lanthony Abbey records that “Gilbertus de Lacy” married “Isabellæ Mareschal”, presumably confusing her with Isabel daughter of William Marshal Earl of Pembroke who married firstly Gilbert de Clare Earl of Gloucester and Hereford and secondly Richard Earl of Cornwall. The Chronicle of Tintern Abbey, Monmouthshire names "Isabella soror Johannis" as daughter of ”Rogerus sive Radulphus Bigod, secundus filius Hugonis le Bigod com. Norfolke et Suffolke…” and his wife “Bertam de Fornivale”, adding that she married firstly "Gilberto de Lacy" and secondly "Johanni Fitz-Geffrey". This must also be incorrect, as any children of Ralph Bigod could not have been born before the late 1220s at the earliest, which is inconsistent with the timing of Isabel’s first marriage. If Isabel was a member of the Bigod family, she must have been the daughter of Hugh and Matilda Marshal of Pembroke. This is the solution adopted by the Complete Peerage. 1
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7 Sep 1233
Pro P. de Rivall' de terra Isabelle que fuit Gileberti de Lascy.—Rex commisit P. de Rivall' terram Isabelle que fuit uxor Gileberti de Lascy, que est de feodo de Grosmund' et spectat ad honorem de Grosmund', qui est in manu ejusdem P. de dono regis, custodiendam quamdiu regi placuerit.
Et mandatum est constabulario de Ewyas quod de predicta terra cum bladis et catallis in eadem terra inventis plenam saisinam habere faciat...
Calendar of Close Rolls, vol. 2, 17 Hen. III, p. 265
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12 Apr 1234, Westminster
Restitution to John son of Geoffrey and Isabel his wife, of the castle and honour of Ewyas Lascy, which were assigned to her in dower of the lands late of Gilbert de Lascy, sometime her husband; and mandate to Drogo de Barentin to deliver the same to him...
Calendar of Patent Rolls, Hen. III, vol. 3, p. 42
25 May 1234, Gloucester
Pro Johanne filio Gaufridi.Mandatum est justiciario Hibernie quod sine dilatione plenam seisinam habere faciat Johanni filio Galfridi et Isabelle uxori ejus de manerio de Conhal' eum pertinentiis, quod est maritagium ipsius Isabelle, et unde disseisiti fuerunt occasione gwerre quam .R. comes Penbr' movit in partibus Hibernie...
8 Aug 1234, Sanderford
Pro Johanne filio Galfridi et Isabella uxore ejus.Mandatum est Walramo Teutonico, constabulario de Grosso Monte, quod talem seisinam habere faciat Johanni filio Galfridi et Isabella uxori ejus de terra sua de Penbedel cum pertinentiis suis, qualem ipsa Isabella inde habuit ante guerram quam Ricardus Marescallus, quondam comes Penbr', movit domino regi, et unde disseisita fuit occasione predicte guerre, ut dicitur, nisi alia occasione inde fuisset disseisita...
Calendar of Close Rolls, vol. 2, 18 Hen. III, pp. 430, 492
Research Notes: