William de PERCY - Lord of Kildale 1169 d. 1203 (VCH YOrks NR 2:250) m. Agnes de Flamville, who m. 2nd. John Birkin. As a widow, she recovered her husband's dower from his tenants. She made a grant to Guisborough Priory "for the good of the souls of both my husbands." (VCH Yorks NR 2:250)
-----------
Robert O'Connor in a post, 20 Dec 2000, adds the following to the above from the same source:
Agnes de Flamville, daughter of Roger de Flamville & his wife Ivetta de Arches (who m. 2nd Adam de Brus). He [William de Percy] was implicated in the massacre of Jews in York. Died before Michaelmas, 1204.