Born in 1653 to Jacques de Rouxel, Comte de Grancey and Médavy as well as Marshal of France, and his second wife Charlotte de Mornay-Villarceaux, Louise-Elisabeth (sometimes also called Isabelle) had twenty-one siblings.
Called Mademoiselle de Grancey, after her father’s property, Louise-Elisabeth found her way into the Household of the King’s brother with the help of her mother and one of her sisters. She swiftly became friends with Philippe de France and rumour has it she acted as a sort of decoy-mistress to distract the court from Philippe’s preference for men. True or not, the young Monsieur and Mademoiselle de Grancey became confidants. These rumours put her into a position of interest as did her rather beautiful face. Madame de Sévigné nicknamed her l’ange and Maurepas calls her the angel of the Palais-Royal.
Mademoiselle de Grancey was given rooms in the Palais-Royal and had a small house in the park of Saint-Cloud. She only appeared occasionally at court, but was in command at the Palais-Royal and ‘ruled’ it.
At some point, Louise-Elisabeth became friendly with the Chevalier de Lorraine and after he returned from his exile in Italy, she became his mistress. According to Monsieur’s second wife Élisabeth-Charlotte aka Liselotte, Mademoiselle de Grancey already had a child by this time. Monsieur intended to make Mademoiselle de Grancey a dame d’atour to Liselotte, but Liselotte was strongly against it. Writing that Louise-Elisabeth is indeed beautiful, but rather stupid in her opinion, and had plenty of admirers. With one of those, Liselotte writes, she had a child, adding that she was very aware there was nothing but friendship between her husband and Louise-Elisabeth, thus no reason to be jealous for her, but the amount of control Louise-Elisabeth had since she was with the Chevalier, was a bit too much for Liselotte. She did not want Louise-Elisabeth to sell positions in her Household, nor did she want others to bribe Louise-Elisabeth in order to get a position. On top of that, says Liselotte, this Mademoiselle de Grancey was quite impudent with her.
Mademoiselle de Grancey’s affair with the Chevalier, who was after all also the lover of Monsieur, did make her lose a bit of favour with the latter. Apparently Monsieur was jealous and rather disgusted at the sight of Mademoiselle de Grancey and the Chevalier de Lorraine, to the degree where he considered to kick both of them out of his house.
According to Madame de Sévigné‘s letters, Monsieur de Villarceaux, a uncle of Louise-Elisabeth, attempted to place her in the King’s bed, but the attempt was rebuffed by the King, who said he was too old to pursue such young things. Villarceaux then related the story to his niece and she refused to see him again, being so enraged about her uncle’s boldness.
Monsieur de Saint-Maurice hints the contrary. He writes “It is assumed that the King is tired of Madame de Montespan and that he looks favourably on Mademoiselle de Grancey, which Monsieur and Madame de Coetquen pushed to favour. Marshal de Grancey, who told me so, is in great alarm. I persuaded him that it will be to his advantage and that of his house. He testifies repugnance, but I believe he wishes it.” Madame de Montespan apparently told the King afterwards that Louise-Elisabeth had a child with the Chevalier de Lorraine. She became his mistress a couple of years later, but might have had something going on with him already before his exile. As Madame de Montespan told the King of them having a child, it seems to have been regarded as rumour. However Louise-Elisabeth is one of several possible mothers of the Chevalier’s son, who was born between 1668 and 1674.
The rumour of Louise-Elisabeth having a child with the Chevalier de Lorraine, apparently made Monsieur place her in the Household of his eldest daughter as dame d’atour. Although Louise-Elisabeth never married, she was called Madame de Grancey from that point on. As Marie-Louise d’Orléans married and became Queen of Spain, Louise-Elisabeth accompanied her to Madrid. She did not stay long in Spain and returned after only a few months. Monsieur made her governess of his younger daughters afterwards. Liselotte did not like this either. For long years already, the clique around the Chevalier de Lorraine, with Madame de Grancey in prominent position, did their best to make her life as hard as possible. This did not change until the late 1680’s, as the Chevalier and along with him Madame de Grancey and the Marquis d’Effiat made peace with Liselotte.
Louise-Elisabeth de Rouxel outlived Monsieur and the Chevalier de Lorraine. She died on November 26 in 1711.