Guy de Beauchamp married 1st by 11 May 1297 (annulled, possibly due to non-completion or even non-consummation), as her 1st husband, Lady Isabel de Clare (married 2nd c1316, as his 2nd wife, 2nd Lord (Baron) Berkeley), daughter of 6th Earl of Gloucester and Hertford of the 1122 creation. [Burke's Peerage]
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He [Maurice de Berkeley] m. 2ndly, about 1316, Isabel, daughter of Gilbert de Clare, Earl of Gloucester and Hertford, by his 1st wife Alice, daughter of Hugh XI, called le Brun, Sire de Lusignan, Count of la Marche and Angouleme (uterine brother of Henry III). He d. as aforesaid, 31 May 1326 , and was buried at Wallingford, but removed to St. Augustine's, Bristol. Inq.p.m. Feb 1326/7. His widow, who was b. 10 Mar 1262/3, dsp 1333. [Complete Peerage II:128-9]