Elisabeth of Lorraine (Elisabeth Therese; 5 April 1664 – 7 March 1748) was a French noblewoman and the Princess of Epinoy by marriage. She is often styled as the princesse de Lillebonne. She was the mother of Louis de Melun, Duke of Joyeuse who disappeared under mysterious circumstances in 1724 and of Anne Julie de Melun, princesse de Soubise.
A member of a cadet branch of the House of Guise, her father was the youngest son of Charles II de Lorrain, Duke of Elbeuf and Catherine Henriette de Bourbon, a natural daughter of Henry IV of France and Gabrielle d'Estrees. Her mother, Anne, was her father's distant cousin and was the only daughter of Charles IV of Lorraine and his secret wife Beatrice de Cusance.
The fifth of her parents' nine children, she was the only one of her siblings to marry or have children. She was styled Mademoiselle de Commercy at the French royal court, the princedom of Commercy being a subsidiary domain of the House of Lorraine.
On 7 October 1691, Mademoiselle de Commercy married Louis de Melun, Prince of Epinoy and Duke of Joyeuse, who was nine years younger than his bride). The couple had two children, one son born in 1694 and a daughter born in 1698. Only the latter would have issue.
Elisabeth Therese was the Duchess of Luxembourg-Saint-Pol in her own right. She bought the duchy from Marie d'Orleans
She was a lady in waiting to Marie Anne de Bourbon, Princess of Conti (1666–1739), a legitimised daughter of Louis XIV of France.
She and her sister were said, by Saint-Simon, to be spies for Madame de Maintenon. While in the circle of the Grand Dauphin, she became close to his other half sister Louise Francoise de Bourbon known as Madame la Duchesse. She was also close to her uncle Charles Henri, Prince of Vaudemont and to Louis Joseph, Duke of Vendome.
In 1721, at the death of her great-aunt, Marguerite Louise d'Orleans, Grand Duchess of Tuscany, Elisabeth Therese was designated her heiress, despite Marguerite Louise having allegedly promised that she would make her children her heirs.
She lost both her children in 1724: Louis, having secretly married Marie Anne de Bourbon (1697–1741), disappeared while at a ball at the Chateau de Chantilly in July. Anne Julie had died earlier from smallpox, leaving five young children.
She and her husband died on 7 March 1748 at the Hotel de Mayenne. She was aged eighty-three.
Through her daughter, she is an ancestor of the present Duke of Montbazon of the House of Rohan.Louis de Melun, Duke of Joyeuse (October 1694 – 31 July 1724) married first to Armande de La Tour d'Auvergne, no issue; married secondly to Marie Anne de Bourbon (1697–1741), no issue;
Anne Julie de Melun (1698 – 18 May 1724) married Jules de Rohan, Prince of Soubise and had issue; was grandmother of Charlotte de Rohan, wife of Louis Joseph, Prince of Conde.
5 April 1664 – 7 October 1691 Her Highness Mademoiselle de Commercy
7 October 1691 – 7 March 1748 Her Highness Madame d'Epinoy