Eleonore d'Esmier d'Olbreuse

Eleonore d'Olbreuse (Olbreuse near La Rochelle, January 3 1639 – Celle, February 5 1722), was Countess of Wilhelmsburg from 1674 and Duchess of Braunschweig-Lüneburg from 1676. She is the great grandmother of Frederick the Great and grandmother of George II of Great Britain.

Eleonore was born in a Huguenot family of lower nobility. Her father was Alexander II d'Esmier d'Olbreuse and her mother Jacquette Poussard de Vandré, Lady of Harburg. She came to the Court in Paris as Lady-in-waiting in the service of the Duchess of Thouars, whose son had married Emily of Hesse-Kassel (or Hesse-Cassel) in 1648.

In the winter of 1664 Eleonore accompanied the Duchess of Thouars who visited her son in Kassel. There the beautiful Eleonore met the unmarried George William, Duke of Brunswick-Lüneburg, who immediately fell in love with her.

Eleonore became his mistress and received the title "Lady of Harburg". In 1666 their only child Sophie Dorothea was born. In 1674 the child was legitimised and Eleonore became Duchess of Wilhelmsburg. Two years later the couple could finally marry. It was a happy marriage.

Their daughter was married in 1682 to George Louis, the son of her father's brother Ernest Augustus, Elector of Hanover for dynastical reasons. The marriage was a disaster. Finally Sophie Dorothea was imprisoned by her husband in the Castle of Ahlden for the rest of her life. Eleonore cared during the last years of her life for her daughter and tried to obtain her release, without success.