Julie, born between 1665 and 1668, was the natural daughter of Henri-Jules de Bourbon, at that time Duc d’Enghien, and Françoise-Charlotte de Montalais, Comtesse de Marans. She is known under various names: Julie de Bourbon, Julie de Gheneni, an anagram of Enghien, or in a slightly different spelling as Julie de Guenani. At court, as Mademoiselle de Châteaubriant.
Her papa was married to Anne-Henriette-Julie de Bavière and started an affair with the Comtesse de Marans, who was the governess of his children, shortly after their wedding. At that point, the Comtesse was widowed for three years already.
Mademoiselle de Châteaubriant was raised at the convent of Maubuisson, there known as Julie de Guenani, and the Abbaye-aux-Bois. As she was fifteen years old, pretty, witty, capricious and a bit fickle, she apparently became the mistress of Louis XIV for a brief time, which would make her his last one. According to rumour, her papa shoved her into the King’s direction in hopes to regain a bit of favour.
He legitimised her in 1683, with the King’s permission, under the name Guenani, and she was meant to become a nun…. but did not want to.
Said to be a very gallant girl, she was courted by Armand de Madaillan Lesparre, Marquis de Lassay, with much fervour. He was madly in love with her and wrote her plenty of emotional love letters….. she wasn’t that much in love with him… but married him anyway, on 5 March 1696 at the Hôtel de Conde, becoming his third wife.
The Marquis was filled with joy that he found himself such a lovely Marquise, but only a day after the vows had been exchanged, Julie made it clear to him that she did not intend to actually live with him. She only married him to gain more independence… and to be with her lover. They separated and she forbade him to make any moves on her, a lady of quality, thus he moved out and she put her lover, the Abbé de Chaulieu, into the conjugal bed.
A year after the marriage, Julie gave birth to a daughter on June 24 in 1697. The girl received the name Anne-Louise de Madaillan Lesparre.
Julie continued to life a rather wild and gallant life with various lovers and plenty of amusements. In the end, it took its toll and she died, apparently insane, in her early forties at the Hôtel de Condé in Paris on March 10 in 1710. Her husband had her buried at the prieuré de Lassay, near Le Mans.