Some time after these occurrences, Mme. de Longueville was stricken with smallpox which, fortunately, did not impair her beauty; it was said, on the contrary, that in taking away its first flower it left all the brilliancy which, joined to her culture and charming languor, made her one of the most attractive persons in France.  La Rochefoucauld has left the following picture of her:  “This princess had all the advantages of esprit and beauty to as great a degree as if nature had taken pleasure in completing, in her person, a perfect work; but these qualities shone less brilliantly on account of one characteristic which led her to imbibe so thoroughly the sentiments of those who adored her that she no longer recognized her own.”

After her twenty-fifth year, Mme. de Longueville became more and more imbued with the general spirit of the seventeenth century:  coquetry and bel esprit became her chief occupation.  The glory of her brother, the Duc d’Enghien, who was rapidly becoming a power, and the probability of the house of Conde becoming dangerous, made Mazarin realize that Mme. de Longueville was to be reckoned with, inasmuch as she had full control over D’Enghien and was constantly instilling new ideas into his mind and requesting from him the distribution of all sorts of favors.  Mazarin, in 1646, succeeded in causing her withdrawal to Muenster for one year; there she ruled as queen of the Congress.  On the death of her father, the Prince of Conde, and at the request of her mother to come home for her lying-in, the husband of Mme. de Longueville consented to her return to Paris.

In the meantime, everything was being done by the Importants to win over the house of Conde and cause a breach between it and Mazarin.  The court at this time was in full glory; to amuse the queen-regent, Mazarin was lavishing money on artists from Italy, and the nobility outdid itself in its attempts to rival royalty in elegance and luxury.  Upon her return, everyone paid homage to Mme. de Longueville; it was at this period that La Rochefoucauld, who was anxious about his position at court, as he was accused of being in league with the Importants and was therefore refused the favors he desired, met Mme. de Longueville who was in the height of her glory and in full control of the most prominent house of the time—­that of the Duc d’Enghien and the Prince de Conti, her brothers.

In order to conquer for himself what the cardinal would not grant him, La Rochefoucauld put forth every effort to win Mme. de Longueville; captivated by his fine appearance, his chivalry and, above all, by his powerful intellect, she gave herself up entirely, willing to share his destiny, to sacrifice all her interests, even those of her family, and the deepest sentiment of her life—­the tenderness for her brother.