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In page Isabel de Clare, 4th Countess of Pembroke:

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In July 1219 she was in France, where she successfully negotiated with King Philip Augustus the possession of her Norman inheritance and did homage to him. While there, she and her son opened negotiations with the king for the marriage of the younger William Marshal with his first cousin, a ploy which caused panic at the English court and a counter-offer of marriage to King Henry III's youngest sister Eleanor.[1] There is evidence that she made good use of her eldest son as her agent in managing the great estates that were hers to dispose of in the months she had them, both of them stonewalling her late husband's executors to avoid paying the debts he left[citation needed].