Isabella Mac William

Isabella mac William (ca. 1165 - ) (Gaelic:Isibéal nic Uilliam) was the illegitimate daughter of William the Lion King of Scots by a daughter of Robert Avenel. She married Robert III de Brus in 1183. They had no children. After his death in 1191, Isabella was married to Robert de Ros, Baron Ros of Wark, (died 1227). They had the following children:

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