Louise Françoise de Bourbon, Duchess of Bourbon
Louise Françoise de Bourbon (1 June 1673 – 16 June 1743) was an illegitimate daughter of King Louis XIV of France and his famous mistress Madame de Montespan. Her marriage to a prince of the blood in 1685 caused great scandal and she had an open rivalry with her older sister Françoise Marie, Duchess of Orléans. She was also responsible for the construction of the Palais Bourbon in Paris which is today used by the French National government. She had a very close relationship with her older half-brother the Grand Dauphin. Several of her children were thought to be illegitimate as, for a majority of her marriage she was having an affair with the Prince of Conti. Even when her husband succeeded to the Condé title the young princess was always known as Madame la Duchesse or the Duchess of Bourbon.