Éléonore Desmier d'Olbreuse

Éléonore Desmier d'Olbreuse, was a French noblewoman, who became first the mistress and later wife of George William of Brunswick, Duke of Lauenburg and Prince of Celle. She was the mother of Sophia Dorothea of Celle, who was the wife of George I of Great Britain. Thus she was the maternal grandmother of George II.